fix(browser): place imports before module const in TimeBasedDebouncer

RENDER_DEBOUNCE_THRESHOLD_MS was declared above the import, which
breaks ES module conventions and can confuse tooling. Move the import
to the top of the module after the license header.

Co-authored-by: Cursor <cursoragent@cursor.com>

.github/workflows/ci.yml

@@ -11,9 +11,9 @@ jobs:
     runs-on: ubuntu-latest
     timeout-minutes: 10
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v3
     - name: Use Node.js 22.x
-      uses: actions/setup-node@v5
+      uses: actions/setup-node@v3
       with:
         node-version: 22.x
         cache: 'npm'
@@ -69,7 +69,7 @@ jobs:
           ./addons/addon-webgl/out/* \
           ./addons/addon-webgl/out-*st/*
     - name: Upload artifacts
-      uses: actions/upload-artifact@v6
+      uses: actions/upload-artifact@v4
       with:
         name: build-artifacts
         path: compressed-build.zip
@@ -79,9 +79,9 @@ jobs:
     runs-on: ubuntu-latest
     timeout-minutes: 10
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v3
     - name: Use Node.js 22.x
-      uses: actions/setup-node@v5
+      uses: actions/setup-node@v3
       with:
         node-version: 22.x
         cache: 'npm'
@@ -100,16 +100,16 @@ jobs:
     runs-on: ubuntu-latest
     timeout-minutes: 10
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v3
     - name: Use Node.js 22.x
-      uses: actions/setup-node@v5
+      uses: actions/setup-node@v3
       with:
         node-version: 22.x
         cache: 'npm'
     - name: Install dependencies
       run: |
         npm ci
-    - uses: actions/download-artifact@v7
+    - uses: actions/download-artifact@v4
       with:
         name: build-artifacts
     - name: Unzip artifacts
@@ -129,7 +129,6 @@ jobs:
         exit $EXIT_CODE
 
   test-unit:
-    needs: build
     timeout-minutes: 20
     strategy:
       matrix:
@@ -137,16 +136,21 @@ jobs:
         runs-on: [ubuntu, macos, windows]
     runs-on: ${{ matrix.runs-on }}-latest
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v3
     - name: Use Node.js ${{ matrix.node-version }}.x
-      uses: actions/setup-node@v5
+      uses: actions/setup-node@v3
       with:
         node-version: ${{ matrix.node-version }}.x
         cache: 'npm'
     - name: Install dependencies
       run: |
         npm ci
-    - uses: actions/download-artifact@v7
+    - name: Wait for build job
+      uses: NathanFirmo/wait-for-other-job@v1.1.1
+      with:
+        token: ${{ secrets.GITHUB_TOKEN }}
+        job: build
+    - uses: actions/download-artifact@v4
       with:
         name: build-artifacts
     - name: Unzip artifacts
@@ -162,7 +166,6 @@ jobs:
       run: npm run test-unit --forbid-only
 
   test-integration:
-    needs: build
     timeout-minutes: 20
     strategy:
       matrix:
@@ -171,9 +174,9 @@ jobs:
         browser: [chromium, firefox, webkit]
     runs-on: ${{ matrix.runs-on }}
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v3
     - name: Use Node.js ${{ matrix.node-version }}.x
-      uses: actions/setup-node@v5
+      uses: actions/setup-node@v3
       with:
         node-version: ${{ matrix.node-version }}.x
         cache: 'npm'
@@ -182,7 +185,12 @@ jobs:
         npm ci
     - name: Install playwright
       run: npx playwright install --with-deps ${{ matrix.browser }}
-    - uses: actions/download-artifact@v7
+    - name: Wait for build job
+      uses: NathanFirmo/wait-for-other-job@v1.1.1
+      with:
+        token: ${{ secrets.GITHUB_TOKEN }}
+        job: build
+    - uses: actions/download-artifact@v4
       with:
         name: build-artifacts
     - name: Unzip artifacts
@@ -232,9 +240,9 @@ jobs:
       matrix:
         node-version: [22]
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v3
     - name: Use Node.js ${{ matrix.node-version }}.x
-      uses: actions/setup-node@v5
+      uses: actions/setup-node@v3
       with:
         node-version: ${{ matrix.node-version }}.x
         cache: 'npm'
@@ -243,7 +251,7 @@ jobs:
         npm ci
     - name: Install playwright
       run: npx playwright install
-    - uses: actions/download-artifact@v7
+    - uses: actions/download-artifact@v4
       with:
         name: build-artifacts
     - name: Unzip artifacts

.github/workflows/codeql-analysis.yml

@@ -24,12 +24,12 @@ jobs:
 
     steps:
     - name: Checkout repository
-      uses: actions/checkout@v5
+      uses: actions/checkout@v3
     - name: Initialize CodeQL
-      uses: github/codeql-action/init@v4
+      uses: github/codeql-action/init@v2
       with:
         languages: ${{ matrix.language }}
     - name: Autobuild
-      uses: github/codeql-action/autobuild@v4
+      uses: github/codeql-action/autobuild@v2
     - name: Perform CodeQL Analysis
-      uses: github/codeql-action/analyze@v4
+      uses: github/codeql-action/analyze@v2

.github/workflows/copilot-setup-steps.yml

@@ -18,9 +18,9 @@ jobs:
 
     steps:
       - name: Checkout code
-        uses: actions/checkout@v5
+        uses: actions/checkout@v4
       - name: Use Node.js 22.x
-        uses: actions/setup-node@v5
+        uses: actions/setup-node@v3
         with:
           node-version: 22.x
           cache: 'npm'

.github/workflows/release.yml

@@ -10,9 +10,9 @@ jobs:
   release:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v3
     - name: Use Node.js 22.x
-      uses: actions/setup-node@v5
+      uses: actions/setup-node@v3
       with:
         node-version: 22.x
         cache: 'npm'

CONTRIBUTING.md

@@ -39,7 +39,7 @@ The preferred way to report bugs or request features is to use
 
 It's pretty common for maintainers of large open source projects to suffer from burnout, especially when needing to triage a large number of incoming issues instead of actually building things. Here are some of the steps we take to try mitigate this:
 
-- Support questions live in [GH discussions](https://github.com/xtermjs/xterm.js/discussions), issues may be transferred there without further comment and core maintainers may or may not participate in discussions.
+- Support questions live in [GH discussions](https://github.com/xtermjs/xterm.js/discussions), issues may be transfered there without further comment and core maintainers may or may not participate in discussions.
 - Issues are strictly for well defined features or bugs that are _actionable_.
 - Sometimes features are out of scope. A common example of this is a niche feature that the pricipal implementation ([VS Code](https://code.visualstudio.com/)) won't leverage and therefore would be difficult to maintain and likely suffer from bitrot. The reporter may not agree with this, but you could always create an addon if that works or maintain your own fork if it comes to that.
 - If a feature does not have a clear way forward or needs more discussion it may be closed ro moved to a discussion.

addons/addon-attach/test/AttachAddon.test.ts

@@ -15,7 +15,7 @@ test.beforeAll(async ({ browser }) => {
 });
 test.afterAll(async () => await ctx.page.close());
 
-test.describe('AttachAddon', () => {
+test.describe('Search Tests', () => {
 
   test.beforeEach(async () => {
     await ctx.proxy.reset();

addons/addon-clipboard/src/ClipboardAddon.ts

@@ -78,43 +78,13 @@ export class BrowserClipboardProvider implements IClipboardProvider {
   }
 }
 
-/**
- * TODO: Once the base64 handling on Uint8Arrays is more common,
- * remove the btoa/atob fallbacks below.
- */
-interface IUint8ArrayB64 extends Uint8Array {
-  toBase64(): string;
-}
-interface IUint8ArrayB64Ctor extends Uint8ArrayConstructor {
-  fromBase64(s: string): IUint8ArrayB64;
-}
-
 export class Base64 implements IBase64 {
   public encodeText(data: string): string {
-    const bytes = new TextEncoder().encode(data) as IUint8ArrayB64;
-    if (bytes.toBase64 !== undefined) {
-      return bytes.toBase64();
-    }
-    let bin = '';
-    for (let i = 0; i < bytes.length; i++) {
-      bin += String.fromCharCode(bytes[i]);
-    }
-    return btoa(bin);
+    return btoa(data);
   }
   public decodeText(data: string): string {
-    if ((Uint8Array as IUint8ArrayB64Ctor).fromBase64 !== undefined) {
-      try {
-        return new TextDecoder().decode((Uint8Array as IUint8ArrayB64Ctor).fromBase64(data));
-      } catch {}
-      return '';
-    }
     try {
-      const bin = atob(data);
-      const bytes = new Uint8Array(bin.length);
-      for (let i = 0; i < bin.length; ++i) {
-        bytes[i] = bin.charCodeAt(i);
-      }
-      return new TextDecoder().decode(bytes);
+      return atob(data);
     } catch {}
     return '';
   }

addons/addon-clipboard/test/ClipboardAddon.test.ts

@@ -29,7 +29,7 @@ test.describe('ClipboardAddon', () => {
       await ctx.page.context().grantPermissions(['clipboard-read', 'clipboard-write']);
     }
     await ctx.page.evaluate(`
-      window.term.reset();
+      window.term.reset()
       window.clipboard?.dispose();
       window.clipboard = new ClipboardAddon();
       window.term.loadAddon(window.clipboard);
@@ -92,22 +92,4 @@ test.describe('ClipboardAddon', () => {
       deepEqual(await ctx.page.evaluate(() => window.navigator.clipboard.readText()), '');
     });
   });
-
-  test.describe('non-ASCII', () => {
-    const testDataEncoded = '4oKsbWzDpMO8dMOf';
-    const testDataDecoded = '€mläütß';
-    test('write simple string', async () => {
-      await ctx.proxy.write(`\x1b]52;c;${testDataEncoded}\x07`);
-      deepEqual(await ctx.page.evaluate(() => window.navigator.clipboard.readText()), testDataDecoded);
-    });
-    test('read simple string', async () => {
-      await ctx.page.evaluate(`
-        window.data2 = [];
-        window.term.onData(e => data2.push(e));
-      `);
-      await ctx.page.evaluate((d) => window.navigator.clipboard.writeText(d), testDataDecoded);
-      await ctx.proxy.write(`\x1b]52;c;?\x07`);
-      deepEqual(await ctx.page.evaluate('window.data2'), [`\x1b]52;c;${testDataEncoded}\x07`]);
-    });
-  });
 });

addons/addon-clipboard/typings/addon-clipboard.d.ts

@@ -82,7 +82,7 @@ declare module '@xterm/addon-clipboard' {
   /**
    * The clipboard provider interface that enables xterm.js to access the browser clipboard.
    *
-   * Note that this clipboard provider does not implement own cut buffers as xterm does,
+   * Note this this clipboard provider does not implement own cut buffers as xterm does,
    * but redirect the selection parameter always to navigator.clipboard.
    */
   export class BrowserClipboardProvider implements IClipboardProvider{

addons/addon-image/README.md

@@ -90,7 +90,7 @@ terminal.loadAddon(imageAddon);
   therefore palette animations cannot be used.
 
 - **SIXEL Raster Attributes Handling**  
-  If raster attributes were found in the SIXEL data (level 2), the image will always be truncated to the given height/width extent. We deviate here from the specification on purpose, as it allows several processing optimizations. For level 1 SIXEL data without any raster attributes the image can freely grow in width and height up to the last data byte, which has a much higher processing penalty. In general encoding libraries should not create level 1 data anymore and should not produce pixel information beyond the announced height/width extent. Both is discouraged by the >30 years old specification.
+  If raster attributes were found in the SIXEL data (level 2), the image will always be truncated to the given height/width extend. We deviate here from the specification on purpose, as it allows several processing optimizations. For level 1 SIXEL data without any raster attributes the image can freely grow in width and height up to the last data byte, which has a much higher processing penalty. In general encoding libraries should not create level 1 data anymore and should not produce pixel information beyond the announced height/width extend. Both is discouraged by the >30 years old specification.
 
   Currently the SIXEL implementation of the addon does not take custom pixel sizes into account, a SIXEL pixel will map 1:1 to a screen pixel.
 
@@ -149,9 +149,9 @@ The addon provides the following API endpoints to retrieve raw image data as can
 
 ### Memory Usage
 
-The addon does most image processing in JavaScript and therefore can occupy a rather big amount of memory. To get an idea where the memory gets eaten, let's look at the data flow and processing steps:
-- Incoming image data chunk at `term.write` (terminal)  
-  `term.write` might stack up incoming chunks. To circumvent this, you will need proper flow control (see xterm.js docs). Note that with image output it is more likely to run into this issue, as it can create lots of MBs in very short time.
+The addon does most image processing in Javascript and therefore can occupy a rather big amount of memory. To get an idea where the memory gets eaten, lets look at the data flow and processing steps:
+- Incomming image data chunk at `term.write` (terminal)  
+  `term.write` might stock up incoming chunks. To circumvent this, you will need proper flow control (see xterm.js docs). Note that with image output it is more likely to run into this issue, as it can create lots of MBs in very short time.
 - Sequence Parser (terminal)  
   The parser operates on a buffer containing up to 2^17 codepoints (~0.5 MB).
 - Sequence Handler - Chunk Decoding (addon)  
@@ -177,18 +177,18 @@ const totalActive = storageBytes + decodingBytes;
 ```
 
 Note that browsers have offloading tricks for rarely touched memory segments, esp. `storageBytes` might not directly translate into real memory usage. Usage peaks will happen during active decoding of multiple big images due to the need of 2 full pixel buffers at the same time, which cannot be offloaded. Thus you may want to keep an eye on `pixelLimit` under limited memory conditions.  
-Further note that the formulas above do not respect the JavaScript object's overhead. Compared to the raw buffer needs the bookkeeping by these objects is rather small (<<5%).
+Further note that the formulas above do not respect the Javascript object's overhead. Compared to the raw buffer needs the book keeping by these objects is rather small (<<5%).
 
 _Why should I care about memory usage at all?_  
-Well you don't have to, and it probably will just work fine with the addon defaults. But for bigger integrations, where much more data is held in the JavaScript context (like multiple terminals on one page), it is likely to hit the engine's memory limit sooner or later under decoding and/or storage pressure.
+Well you don't have to, and it probably will just work fine with the addon defaults. But for bigger integrations, where much more data is held in the Javascript context (like multiple terminals on one page), it is likely to hit the engine's memory limit sooner or later under decoding and/or storage pressure.
 
 _How can I adjust the memory usage?_  
 - `pixelLimit`  
-  A constructor setting, thus you would have to anticipate, whether (multiple) terminals in your page gonna do lots of concurrent decoding. Since this is normally not the case and the memory usage only peaks temporarily, a rather high value should work even with multiple terminals in one page.
+  A constructor setting, thus you would have to anticipate, whether (multiple) terminals in your page gonna do lots of concurrent decoding. Since this is normally not the case and the memory usage is only temporarily peaking, a rather high value should work even with multiple terminals in one page.
 - `storageLimit`  
-  A constructor and a runtime setting. In conjunction with `storageUsage` you can do runtime checks and adjust the limit to your needs. If you have to lower the limit below the current usage, images will be removed in FIFO order and may turn into a placeholder in the terminal's scrollback (if `showPlaceholder` is set). When adjusting keep in mind to leave enough room for peak memory use during decoding.
+  A constructor and a runtime setting. In conjunction with `storageUsage` you can do runtime checks and adjust the limit to your needs. If you have to lower the limit below the current usage, images will be removed in FIFO order and may turn into a placeholder in the terminal's scrollback (if `showPlaceholder` is set). When adjusting keep in mind to leave enough room for memory peaking for decoding.
 - `sixelSizeLimit | iipSizeLimit | kittySizeLimit`  
-  Constructor settings. This has only a small impact on peak memory during decoding. It is meant to avoid processing of overly big or broken image sequences at an earlier phase, thus may stop the invoked decoders from entering memory intensive tasks for potentially invalid data.
+  Constructor settings. This has only a small impact on peaking memory during decoding. It is meant to avoid processing of overly big or broken image sequences at an earlier phase, thus may stop the invoked decoders from entering memory intensive tasks for potentially invalid data.
 
 
 ### Terminal Interaction

addons/addon-image/src/ImageStorage.ts

@@ -436,9 +436,9 @@ export class ImageStorage implements IDisposable {
       for (let col = 0; col < cols; ++col) {
         let e: IExtendedAttrsImage;
         if (line.getBg(col) & BgFlags.HAS_EXTENDED) {
-          e = line._extendedAttrs?.[col] ?? EMPTY_ATTRS;
+          e = line._extendedAttrs[col] ?? EMPTY_ATTRS;
         } else {
-          const maybeImg = line._extendedAttrs?.[col] as IExtendedAttrsImage | undefined;
+          const maybeImg = line._extendedAttrs[col] as IExtendedAttrsImage | undefined;
           if (!maybeImg || maybeImg.imageId === undefined || maybeImg.imageId === -1) {
             continue;
           }
@@ -461,7 +461,7 @@ export class ImageStorage implements IDisposable {
            * Also check _extendedAttrs directly for cells where text cleared HAS_EXTENDED.
            */
           while (++col < cols) {
-            const nextE = line._extendedAttrs?.[col] as IExtendedAttrsImage | undefined;
+            const nextE = line._extendedAttrs[col] as IExtendedAttrsImage | undefined;
             if (!nextE || nextE.imageId !== imageId || nextE.tileId !== startTile + count) {
               break;
             }
@@ -515,7 +515,7 @@ export class ImageStorage implements IDisposable {
     for (let row = 0; row < rows; ++row) {
       const line = buffer.lines.get(row) as IBufferLineExt;
       if (line.getBg(oldCol) & BgFlags.HAS_EXTENDED) {
-        const e: IExtendedAttrsImage = line._extendedAttrs?.[oldCol] ?? EMPTY_ATTRS;
+        const e: IExtendedAttrsImage = line._extendedAttrs[oldCol] ?? EMPTY_ATTRS;
         const imageId = e.imageId;
         if (imageId === undefined || imageId === -1) {
           continue;
@@ -560,7 +560,7 @@ export class ImageStorage implements IDisposable {
     const buffer = this._terminal._core.buffer;
     const line = buffer.lines.get(y) as IBufferLineExt;
     if (line && line.getBg(x) & BgFlags.HAS_EXTENDED) {
-      const e: IExtendedAttrsImage = line._extendedAttrs?.[x] ?? EMPTY_ATTRS;
+      const e: IExtendedAttrsImage = line._extendedAttrs[x] ?? EMPTY_ATTRS;
       if (e.imageId && e.imageId !== -1) {
         const orig = this._images.get(e.imageId)?.orig;
         if (window.ImageBitmap && orig instanceof ImageBitmap) {
@@ -580,7 +580,7 @@ export class ImageStorage implements IDisposable {
     const buffer = this._terminal._core.buffer;
     const line = buffer.lines.get(y) as IBufferLineExt;
     if (line && line.getBg(x) & BgFlags.HAS_EXTENDED) {
-      const e: IExtendedAttrsImage = line._extendedAttrs?.[x] ?? EMPTY_ATTRS;
+      const e: IExtendedAttrsImage = line._extendedAttrs[x] ?? EMPTY_ATTRS;
       if (e.imageId && e.imageId !== -1 && e.tileId !== -1) {
         const spec = this._images.get(e.imageId);
         if (spec) {
@@ -611,7 +611,7 @@ export class ImageStorage implements IDisposable {
 
   private _writeToCell(line: IBufferLineExt, x: number, imageId: number, tileId: number): void {
     if (line._data[x * Cell.SIZE + Cell.BG] & BgFlags.HAS_EXTENDED) {
-      const old = line._extendedAttrs?.[x];
+      const old = line._extendedAttrs[x];
       if (old) {
         if (old.imageId !== undefined) {
           // found an old ExtendedAttrsImage, since we know that
@@ -627,13 +627,13 @@ export class ImageStorage implements IDisposable {
           return;
         }
         // found a plain ExtendedAttrs instance, clone it to new entry
-        (line._extendedAttrs ??= {})[x] = new ExtendedAttrsImage(old.ext, old.urlId, imageId, tileId);
+        line._extendedAttrs[x] = new ExtendedAttrsImage(old.ext, old.urlId, imageId, tileId);
         return;
       }
     }
     // fall-through: always create new ExtendedAttrsImage entry
     line._data[x * Cell.SIZE + Cell.BG] |= BgFlags.HAS_EXTENDED;
-    (line._extendedAttrs ??= {})[x] = new ExtendedAttrsImage(0, 0, imageId, tileId);
+    line._extendedAttrs[x] = new ExtendedAttrsImage(0, 0, imageId, tileId);
   }
 
   private _evictOnAlternate(): void {
@@ -652,7 +652,7 @@ export class ImageStorage implements IDisposable {
       }
       for (let x = 0; x < this._terminal.cols; ++x) {
         if (line._data[x * Cell.SIZE + Cell.BG] & BgFlags.HAS_EXTENDED) {
-          const imgId = line._extendedAttrs?.[x]?.imageId;
+          const imgId = line._extendedAttrs[x]?.imageId;
           if (imgId) {
             const spec = this._images.get(imgId);
             if (spec) {

addons/addon-image/src/Types.ts

@@ -64,7 +64,7 @@ export interface IExtendedAttrsImage extends IExtendedAttrs {
 
 /* eslint-disable */
 export interface IBufferLineExt extends IBufferLine {
-  _extendedAttrs: {[index: number]: IExtendedAttrsImage | undefined} | undefined;
+  _extendedAttrs: {[index: number]: IExtendedAttrsImage | undefined};
   _data: Uint32Array;
 }
 

addons/addon-image/test/ImageAddon.test.ts

@@ -118,10 +118,7 @@ test.describe('ImageAddon', () => {
     }
     // bufferline privates
     strictEqual(await ctx.page.evaluate('window.term._core.buffer.lines.get(0)._data instanceof Uint32Array'), true);
-    strictEqual(await ctx.page.evaluate(`(() => {
-      const ea = window.term._core.buffer.lines.get(0)._extendedAttrs;
-      return ea === undefined || (typeof ea === 'object' && ea !== null);
-    })()`), true);
+    strictEqual(await ctx.page.evaluate('window.term._core.buffer.lines.get(0)._extendedAttrs instanceof Object'), true);
     // inputhandler privates
     strictEqual(await ctx.page.evaluate('window.term._core._inputHandler._curAttrData.constructor.name'), '_AttributeData');
     strictEqual(await ctx.page.evaluate('window.term._core._inputHandler._parser.constructor.name'), 'EscapeSequenceParser');

addons/addon-ligatures/src/index.ts

@@ -21,7 +21,7 @@ const CACHE_SIZE = 100000;
 
 /**
  * Enable ligature support for the provided Terminal instance. To function
- * properly, this must be called after `open()` is called on the terminal. If
+ * properly, this must be called after `open()` is called on the therminal. If
  * the font currently in use supports ligatures, the terminal will automatically
  * start to render them.
  * @param term Terminal instance from xterm.js

addons/addon-search/src/DecorationManager.test.ts

@@ -1,81 +0,0 @@
-/**
- * Copyright (c) 2026 The xterm.js authors. All rights reserved.
- * @license MIT
- */
-
-import { assert } from 'chai';
-import { DecorationManager } from './DecorationManager';
-import { SearchEngine } from './SearchEngine';
-import { SearchLineCache } from './SearchLineCache';
-import { Terminal } from 'browser/public/Terminal';
-import type { ISearchDecorationOptions } from '@xterm/addon-search';
-import type { IDecorationOptions } from '@xterm/xterm';
-import { DisposableStore } from 'common/Lifecycle';
-
-function writeP(terminal: Terminal, data: string): Promise<void> {
-  return new Promise(r => terminal.write(data, r));
-}
-
-describe('DecorationManager', () => {
-  let store: DisposableStore;
-  let terminal: Terminal;
-  let decorationManager: DecorationManager;
-
-  beforeEach(() => {
-    store = new DisposableStore();
-    terminal = store.add(new Terminal({ cols: 10, rows: 5 }));
-    decorationManager = store.add(new DecorationManager(terminal));
-  });
-
-  it('should split highlight decorations for a wrapped match', async () => {
-    await writeP(terminal, '0123456789abcde');
-    const searchEngine = new SearchEngine(terminal, store.add(new SearchLineCache(terminal)));
-    const match = searchEngine.find('9abc', 0, 0);
-    assert.ok(match);
-
-    const decorationOptions: IDecorationOptions[] = [];
-    const registerDecoration = terminal.registerDecoration.bind(terminal);
-    terminal.registerDecoration = (options: IDecorationOptions) => {
-      decorationOptions.push(options);
-      return registerDecoration(options);
-    };
-
-    const options: ISearchDecorationOptions = {
-      matchOverviewRuler: '#ff0000',
-      activeMatchColorOverviewRuler: '#00ff00'
-    };
-    decorationManager.createHighlightDecorations([match], options);
-
-    assert.strictEqual(decorationOptions.length, 2);
-    assert.strictEqual(decorationOptions[0].x, 9);
-    assert.strictEqual(decorationOptions[0].width, 1);
-    assert.strictEqual(decorationOptions[1].x, 0);
-    assert.strictEqual(decorationOptions[1].width, 3);
-
-    const withOverviewRuler = decorationOptions.filter(o => o.overviewRulerOptions !== undefined);
-    assert.strictEqual(withOverviewRuler.length, 2);
-  });
-
-  it('should only add one overview ruler marker per buffer line', async () => {
-    await writeP(terminal, 'abcdefghij');
-    const decorationOptions: IDecorationOptions[] = [];
-    const registerDecoration = terminal.registerDecoration.bind(terminal);
-    terminal.registerDecoration = (options: IDecorationOptions) => {
-      decorationOptions.push(options);
-      return registerDecoration(options);
-    };
-
-    const options: ISearchDecorationOptions = {
-      matchOverviewRuler: '#ff0000',
-      activeMatchColorOverviewRuler: '#00ff00'
-    };
-    decorationManager.createHighlightDecorations([
-      { term: 'a', col: 0, row: 0, size: 1 },
-      { term: 'f', col: 5, row: 0, size: 1 }
-    ], options);
-
-    const withOverviewRuler = decorationOptions.filter(o => o.overviewRulerOptions !== undefined);
-    assert.strictEqual(withOverviewRuler.length, 1);
-    assert.strictEqual(withOverviewRuler[0].x, 0);
-  });
-});

addons/addon-search/src/SearchEngine.ts

@@ -60,7 +60,7 @@ export class SearchEngine {
       this._terminal.clearSelection();
       return undefined;
     }
-    if (startCol >= this._terminal.cols) {
+    if (startCol > this._terminal.cols) {
       throw new Error(`Invalid col: ${startCol} to search in terminal of ${this._terminal.cols} cols`);
     }
 

addons/addon-search/test/SearchAddon.test.ts

@@ -417,7 +417,7 @@ test.describe('Search Tests', () => {
     test.describe('#2444 wrapped line content not being found', () => {
       let fixture: string;
       test.beforeAll(async () => {
-        fixture = (await new Promise<Buffer>((res, rej) => readFile(resolve(__dirname, '../fixtures/issue-2444'), (err, data) => err ? rej(err) : res(data)))).toString();
+        fixture = (await new Promise<Buffer>(r => readFile(resolve(__dirname, '../fixtures/issue-2444'), (err, data) => r(data)))).toString();
         if (process.platform !== 'win32') {
           fixture = fixture.replace(/\n/g, '\n\r');
         }
@@ -501,7 +501,7 @@ test.describe('Search Tests', () => {
         window.search.onDidChangeResults(e => window.calls.push(e));
       `);
       // Move cursor forward 1 time to create a null character, as opposed to regular whitespace
-      await ctx.proxy.write('\x1b[CHi Hi');
+      await ctx.proxy.write('\\x1b[CHi Hi');
       strictEqual(await ctx.page.evaluate(`window.search.findPrevious('h', { decorations: { activeMatchColorOverviewRuler: '#ff0000' } })`), true);
       deepStrictEqual(await ctx.page.evaluate('window.calls'), [
         { resultCount: 2, resultIndex: 1 }

addons/addon-serialize/src/SerializeAddon.ts

@@ -173,7 +173,7 @@ class StringSerializeHandler extends BaseSerializeHandler {
   private _thisRowLastSecondChar: IBufferCell = this._buffer.getNullCell();
   private _nextRowFirstChar: IBufferCell = this._buffer.getNullCell();
   protected _rowEnd(row: number, isLastRow: boolean): void {
-    // if there is colorful empty cell at line end, we must pad it back, or the color block
+    // if there is colorful empty cell at line end, whe must pad it back, or the the color block
     // will missing
     if (this._nullCellCount > 0 && !equalBg(this._cursorStyle, this._backgroundCell)) {
       // use clear right to set background.
@@ -221,7 +221,7 @@ class StringSerializeHandler extends BaseSerializeHandler {
             // you can't use control sequence to move cursor to (x === row)
             (thisRowLastChar.getChars() || thisRowLastChar.getWidth() === 0) &&
             // change background of the first wrapped cell also affects BCE
-            // so we mark it as invalid to simplify the process to determine line separator
+            // so we mark it as invalid to simply the process to determine line separator
             equalBg(thisRowLastChar, nextRowFirstChar)
           ) {
             isValid = true;
@@ -233,7 +233,7 @@ class StringSerializeHandler extends BaseSerializeHandler {
             isNextRowFirstCharDoubleWidth &&
             (thisRowLastSecondChar.getChars() || thisRowLastSecondChar.getWidth() === 0) &&
             // change background of the first wrapped cell also affects BCE
-            // so we mark it as invalid to simplify the process to determine line separator
+            // so we mark it as invalid to simply the process to determine line separator
             equalBg(thisRowLastChar, nextRowFirstChar) &&
             equalBg(thisRowLastSecondChar, nextRowFirstChar)
           ) {

addons/addon-serialize/test/SerializeAddon.test.ts

@@ -192,7 +192,7 @@ test.describe('SerializeAddon', () => {
     const cols = 10;
     const line = '+'.repeat(cols);
     const lines: string[] = [
-      sgr(FG_P16_GREEN) + line,  // Workaround: If we clear all flags at the end, serialize will use \x1b[0m to clear instead of the specific disable sequence
+      sgr(FG_P16_GREEN) + line,  // Workaround: If we clear all flags a the end, serialize will use \x1b[0m to clear instead of the sepcific disable sequence
       sgr(INVERSE) + line,
       sgr(BOLD) + line,
       sgr(UNDERLINED) + line,

addons/addon-unicode-graphemes/src/UnicodeGraphemesAddon.ts

@@ -2,7 +2,7 @@
  * Copyright (c) 2023 The xterm.js authors. All rights reserved.
  * @license MIT
  *
- * UnicodeVersionProvider for V15 with grapheme cluster handling.
+ * UnicodeVersionProvider for V15 with grapeme cluster handleing.
  */
 
 import type { Terminal, ITerminalAddon, IUnicodeHandling } from '@xterm/xterm';

addons/addon-web-links/src/WebLinkProvider.ts

@@ -57,8 +57,7 @@ function isUrl(urlString: string): boolean {
 
 export class LinkComputer {
   public static computeLink(y: number, regex: RegExp, terminal: Terminal, activate: (event: MouseEvent, uri: string) => void): ILink[] {
-    const flags = regex.flags.includes('g') ? regex.flags : `${regex.flags}g`;
-    const rex = new RegExp(regex.source, flags);
+    const rex = new RegExp(regex.source, (regex.flags || '') + 'g');
 
     const [lines, startLineIndex] = LinkComputer._getWindowedLineStrings(y - 1, terminal);
     const line = lines.join('');

addons/addon-web-links/src/WebLinksAddon.ts

@@ -7,13 +7,13 @@ import type { Terminal, ITerminalAddon, IDisposable } from '@xterm/xterm';
 import type { WebLinksAddon as IWebLinksApi } from '@xterm/addon-web-links';
 import { ILinkProviderOptions, WebLinkProvider } from './WebLinkProvider';
 
-// consider everything starting with http:// or https://
+// consider everthing starting with http:// or https://
 // up to first whitespace, `"` or `'` as url
 // NOTE: The repeated end clause is needed to not match a dangling `:`
 // resembling the old (...)*([^:"\'\\s]) final path clause
 // additionally exclude early + final:
 // - unsafe from rfc3986: !*'()
-// - unsafe chars from rfc1738: {}|\^~[]` (minus [] for ipv6 addresses, also allow ~)
+// - unsafe chars from rfc1738: {}|\^~[]` (minus [] as we need them for ipv6 adresses, also allow ~)
 // also exclude as finals:
 // - final interpunction like ,.!?
 // - any sort of brackets <>()[]{} (not spec conform, but often used to enclose urls)

addons/addon-webgl/README.md

@@ -23,7 +23,7 @@ See the full [API](https://github.com/xtermjs/xterm.js/blob/master/addons/addon-
 
 ### Handling Context Loss
 
-The browser may drop WebGL contexts for various reasons like OOM or after the system has been suspended. There is an API exposed that fires the `webglcontextlost` event on the canvas so embedders can handle it however they wish. An easy, but suboptimal way, to handle this is by disposing of WebglAddon when the event fires:
+The browser may drop WebGL contexts for various reasons like OOM or after the system has been suspended. There is an API exposed that fires the `webglcontextlost` event fired on the canvas so embedders can handle it however they wish. An easy, but suboptimal way, to handle this is by disposing of WebglAddon when the event fires:
 
 ```ts
 const terminal = new Terminal();

addons/addon-webgl/src/GlyphRenderer.ts

@@ -220,7 +220,7 @@ export class GlyphRenderer extends Disposable {
   public updateCell(x: number, y: number, code: number, bg: number, fg: number, ext: number, chars: string, width: number, lastBg: number): void {
     // Since this function is called for every cell (`rows*cols`), it must be very optimized. It
     // should not instantiate any variables unless a new glyph is drawn to the cache where the
-    // slight slowdown is acceptable for the developer ergonomics provided as it's a one-off for
+    // slight slowdown is acceptable for the developer ergonomics provided as it's a once of for
     // each glyph.
     this._updateCell(this._vertices.attributes, x, y, code, bg, fg, ext, chars, width, lastBg);
   }
@@ -389,9 +389,8 @@ export class GlyphRenderer extends Disposable {
     gl.bindTexture(gl.TEXTURE_2D, this._atlasTextures[i].texture);
     gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE);
     gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE);
-    gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR);
-    gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.LINEAR);
     gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, gl.RGBA, gl.UNSIGNED_BYTE, atlas.pages[i].canvas);
+    gl.generateMipmap(gl.TEXTURE_2D);
     this._atlasTextures[i].version = atlas.pages[i].version;
   }
 

addons/addon-webgl/src/TextureAtlas.ts

@@ -69,7 +69,7 @@ export class TextureAtlas implements ITextureAtlas {
   private _overflowSizePage: AtlasPage | undefined;
 
   private _tmpCanvas: HTMLCanvasElement;
-  // A temporary context that glyphs are drawn to before being transferred to the atlas.
+  // A temporary context that glyphs are drawn to before being transfered to the atlas.
   private _tmpCtx: CanvasRenderingContext2D;
 
   private _workBoundingBox: IBoundingBox = { top: 0, left: 0, bottom: 0, right: 0 };
@@ -152,7 +152,7 @@ export class TextureAtlas implements ITextureAtlas {
   }
 
   private _createNewPage(): AtlasPage {
-    // Try merge the set of the 4 most used pages of the largest size. This is deferred to a
+    // Try merge the set of the 4 most used pages of the largest size. This is is deferred to a
     // microtask to ensure it does not interrupt textures that will be rendered in the current
     // animation frame which would result in blank rendered areas. This is actually not that
     // expensive relative to drawing the glyphs, so there is no need to wait for an idle callback.
@@ -191,7 +191,7 @@ export class TextureAtlas implements ITextureAtlas {
         return newPage;
       }
 
-      const sortedMergingPagesIndexes = mergingPages.map(e => e.glyphs[0].texturePage).sort((a, b) => a - b);
+      const sortedMergingPagesIndexes = mergingPages.map(e => e.glyphs[0].texturePage).sort((a, b) => a > b ? 1 : -1);
       const mergedPageIndex = this.pages.length - mergingPages.length;
 
       // Merge into the new page
@@ -1080,33 +1080,17 @@ class AtlasPage {
     size: number,
     sourcePages?: AtlasPage[]
   ) {
+    if (sourcePages) {
+      for (const p of sourcePages) {
+        this._glyphs.push(...p.glyphs);
+        this._usedPixels += p._usedPixels;
+      }
+    }
     this.canvas = createCanvas(document, size, size);
     // The canvas needs alpha because we use clearColor to convert the background color to alpha.
     // It might also contain some characters with transparent backgrounds if allowTransparency is
     // set.
     this.ctx = throwIfFalsy(this.canvas.getContext('2d', { alpha: true }));
-    if (sourcePages) {
-      if (sourcePages.length === 4) {
-        // optimized for quadmerge
-        this._glyphs = this._glyphs.concat(
-          sourcePages[0].glyphs,
-          sourcePages[1].glyphs,
-          sourcePages[2].glyphs,
-          sourcePages[3].glyphs
-        );
-        this._usedPixels = sourcePages[0]._usedPixels +
-          sourcePages[1]._usedPixels +
-          sourcePages[2]._usedPixels +
-          sourcePages[3]._usedPixels;
-      } else {
-        // fallback for non quadmerges (should never be used)
-        for (let i = 0; i < sourcePages.length; ++i) {
-          this._glyphs = this._glyphs.concat(sourcePages[i].glyphs);
-          this._usedPixels += sourcePages[i]._usedPixels;
-        }
-
-      }
-    }
   }
 
   public clear(): void {
@@ -1141,7 +1125,7 @@ function clearColor(imageData: ImageData, bg: IColor, fg: IColor, enableThreshol
   // were covered (fg=#8ae234, bg=#c4a000).
   const threshold = Math.floor((Math.abs(r - fgR) + Math.abs(g - fgG) + Math.abs(b - fgB)) / 12);
 
-  // Set alpha channel of relevant pixels to 0
+  // Set alpha channel of relevent pixels to 0
   let isEmpty = true;
   for (let offset = 0; offset < imageData.data.length; offset += 4) {
     // Check exact match

addons/addon-webgl/src/WebglAddon.ts

@@ -40,7 +40,7 @@ export class WebglAddon extends Disposable implements ITerminalAddon, IWebglApi
       };
       const gl = document.createElement('canvas').getContext('webgl2', contextAttributes) as IWebGL2RenderingContext;
       if (!gl) {
-        throw new Error('WebGL2 is only supported on Safari 16 and above');
+        throw new Error('Webgl2 is only supported on Safari 16 and above');
       }
     }
     super();

addons/addon-webgl/src/WebglRenderer.ts

@@ -456,18 +456,7 @@ export class WebglRenderer extends Disposable implements IRenderer {
 
     for (y = start; y <= end; y++) {
       row = y + terminal.buffer.ydisp;
-      const bufferLine = terminal.buffer.lines.get(row);
-      if (!bufferLine) {
-        this._model.lineLengths[y] = 0;
-        for (x = 0; x < terminal.cols; x++) {
-          j = ((y * terminal.cols) + x) * RenderModelConstants.INDICIES_PER_CELL;
-          modelUpdated = true;
-          this._nullModelCell(x, y, j, 0, 0, 0);
-        }
-        this._setRowBlinkState(y, false);
-        continue;
-      }
-      line = bufferLine;
+      line = terminal.buffer.lines.get(row)!;
       let rowHasBlinkingCells = false;
       this._model.lineLengths[y] = 0;
       isCursorRow = cursorY === row;
@@ -598,9 +587,13 @@ export class WebglRenderer extends Disposable implements IRenderer {
           // Null out non-first cells
           for (x++; x <= lastCharX; x++) {
             j = ((y * terminal.cols) + x) * RenderModelConstants.INDICIES_PER_CELL;
+            this._glyphRenderer.value!.updateCell(x, y, NULL_CELL_CODE, 0, 0, 0, NULL_CELL_CHAR, 0, 0);
+            this._model.cells[j] = NULL_CELL_CODE;
             // Don't re-resolve the cell color since multi-colored ligature backgrounds are not
             // supported
-            this._nullModelCell(x, y, j, this._cellColorResolver.result.bg, this._cellColorResolver.result.fg, this._cellColorResolver.result.ext);
+            this._model.cells[j + RenderModelConstants.BG_OFFSET] = this._cellColorResolver.result.bg;
+            this._model.cells[j + RenderModelConstants.FG_OFFSET] = this._cellColorResolver.result.fg;
+            this._model.cells[j + RenderModelConstants.EXT_OFFSET] = this._cellColorResolver.result.ext;
           }
           x--; // Go back to the previous update cell for next iteration
         }
@@ -614,14 +607,6 @@ export class WebglRenderer extends Disposable implements IRenderer {
     this._updateTextBlinkState();
   }
 
-  private _nullModelCell(x: number, y: number, cellIndex: number, bg: number, fg: number, ext: number): void {
-    this._glyphRenderer.value!.updateCell(x, y, NULL_CELL_CODE, bg, fg, ext, NULL_CELL_CHAR, 0, 0);
-    this._model.cells[cellIndex] = NULL_CELL_CODE;
-    this._model.cells[cellIndex + RenderModelConstants.BG_OFFSET] = bg;
-    this._model.cells[cellIndex + RenderModelConstants.FG_OFFSET] = fg;
-    this._model.cells[cellIndex + RenderModelConstants.EXT_OFFSET] = ext;
-  }
-
   private _resetBlinkingRowState(): void {
     this._rowHasBlinkingCells = new Array(this._terminal.rows).fill(false);
     this._rowHasBlinkingCellsCount = 0;
@@ -679,10 +664,10 @@ export class WebglRenderer extends Disposable implements IRenderer {
     this.dimensions.device.canvas.height = this._terminal.rows * this.dimensions.device.cell.height;
     this.dimensions.device.canvas.width = this._terminal.cols * this.dimensions.device.cell.width;
 
-    // The size of the canvas on the page. It's important that this rounds to nearest integer
+    // The the size of the canvas on the page. It's important that this rounds to nearest integer
     // and not ceils as browsers often have floating point precision issues where
     // `window.devicePixelRatio` ends up being something like `1.100000023841858` for example, when
-    // it's actually 1.1. Ceiling may cause blurriness as the backing canvas image is 1 pixel too
+    // it's actually 1.1. Ceiling may causes blurriness as the backing canvas image is 1 pixel too
     // large for the canvas element size.
     this.dimensions.css.canvas.height = Math.round(this.dimensions.device.canvas.height / this._devicePixelRatio);
     this.dimensions.css.canvas.width = Math.round(this.dimensions.device.canvas.width / this._devicePixelRatio);

addons/addon-webgl/typings/addon-webgl.d.ts

@@ -23,12 +23,12 @@ declare module '@xterm/addon-webgl' {
     public readonly onChangeTextureAtlas: IEvent<HTMLCanvasElement>;
 
     /**
-     * An event that is fired when a new page is added to the texture atlas.
+     * An event that is fired when the a new page is added to the texture atlas.
      */
     public readonly onAddTextureAtlasCanvas: IEvent<HTMLCanvasElement>;
 
     /**
-     * An event that is fired when a page is removed from the texture atlas.
+     * An event that is fired when the a page is removed from the texture atlas.
      */
     public readonly onRemoveTextureAtlasCanvas: IEvent<HTMLCanvasElement>;
 

bin/esbuild_all.mjs

@@ -19,17 +19,14 @@ for (const addon of addons) {
 // Demo job - This requires the others to be built so it's not included when building all
 // jobs.push(createJob('demo-client', [`--demo-client`]));
 
-const codes = await Promise.all(jobs.map(job => {
+await Promise.all(jobs.map((job, i) => {
   return new Promise(r => {
     job.cp.on('exit', code => {
       log(`Finished \x1b[32m${job.name}\x1b[0m${code ? ' \x1b[31mwith errors\x1b[0m' : ''}`);
-      r(code ?? 1);
+      r(code);
     });
   });
 }));
-if (codes.some(code => code !== 0)) {
-  process.exit(1);
-}
 
 /**
  * @param {string} message

bin/setup-full.mjs

@@ -5,7 +5,7 @@ import { spawnSync } from 'node:child_process';
 import { basename, dirname, resolve, sep } from 'node:path';
 import { fileURLToPath } from 'node:url';
 
-const repoRoot = resolve(dirname(fileURLToPath(import.meta.url)), '..');
+const repoRoot = resolve(dirname(fileURLToPath(import.meta.url)), '../..');
 const nodeModulesPath = resolve(repoRoot, 'node_modules');
 const npmExecutable = process.platform === 'win32' ? 'npm.cmd' : 'npm';
 
@@ -13,7 +13,7 @@ const npmExecutable = process.platform === 'win32' ? 'npm.cmd' : 'npm';
 
 /** @param {string} message */
 function log(message) {
-  console.info(`[setup-full] ${message}`);
+  console.info(`[setup-fast] ${message}`);
 }
 
 /** @param {string[]} args */

bin/test_integration.js

@@ -12,7 +12,7 @@ let argv = process.argv.slice(2);
 let suiteFilter = undefined;
 while (argv.some(e => e.startsWith('--suite='))) {
   const i = argv.findIndex(e => e.startsWith('--suite='));
-  const match = argv[i].match(/--suite=(?<suitename>.+)/);
+  const match = argv[i].match(/--suite=(?<suitename>.+)/)
   suiteFilter = match?.groups?.suitename ?? undefined;
   argv.splice(i, 1);
 }
@@ -42,18 +42,12 @@ if (suiteFilter) {
   configs = configs.filter(e => e.name === suiteFilter);
 }
 
-if (suiteFilter && configs.length === 0) {
-  console.error(`Unknown suite: ${suiteFilter}`);
-  process.exit(1);
-}
-
 function npmBinScript(script) {
   return path.resolve(__dirname, `../node_modules/.bin/` + (process.platform === 'win32' ?
     `${script}.cmd` : script));
 }
 
 async function run() {
-  let exitCode = 0;
   for (const config of configs) {
     const command = npmBinScript('playwright');
     const args = ['test', '-c', config.path, ...argv];
@@ -68,13 +62,10 @@ async function run() {
 
     if (run.error) {
       console.error(run.error);
-      process.exit(run.status ?? 1);
+      process.exit(run.status ?? -1);
     }
 
-    if (run.status) {
-      exitCode = run.status;
-    }
+    process.exit(run.status);
   }
-  process.exit(exitCode);
 }
 run();

bin/test_mousemodes.js

@@ -177,7 +177,7 @@ const ENC = {
 }
 
 function printMenu() {
-  console.log('\x1b[2J\x1b[HTest mouse reports [Ctrl-C to exit]');
+  console.log('\x1b[2J\x1b\[HTest mouse reports [Ctrl-C to exit]');
   console.log();
   console.log('  Selected protocol [Ctrl-A to switch]');
   const protocols = Object.keys(PROTOCOLS);

bin/test_unit.js

@@ -21,7 +21,7 @@ if (process.argv.length > 2) {
   flagArgs = args.filter(e => e.startsWith('--'));
   // ability to inject particular test files via
   // npm run test [testFileA testFileB ...]
-  const files = args.filter(e => !e.startsWith('--'));
+  files = args.filter(e => !e.startsWith('--'));
   if (files.length) {
     testFiles = files;
   }
@@ -39,6 +39,8 @@ if (checkCoverage) {
     ...testFiles,
     ...flagArgs
   ];
+  console.info('executable', executable);
+  console.info('args', args);
   const run = cp.spawnSync(
     executable,
     args,
@@ -49,7 +51,7 @@ if (checkCoverage) {
       stdio: 'inherit'
     }
   );
-  process.exit(run.status ?? -1);
+  process.exit(run.status);
 }
 
 const run = cp.spawnSync(

demo/client/components/window/webglWindow.ts

@@ -11,33 +11,8 @@ export class WebglWindow extends BaseWindow implements IControlWindow {
   public readonly label = 'webgl';
 
   private _textureAtlasContainer!: HTMLElement;
-  private _stressRunning = false;
-  private _stressScrolling: HTMLInputElement | undefined;
 
   public build(container: HTMLElement): void {
-    const stressDiv = document.createElement('div');
-    const stressStart = document.createElement('button');
-    stressStart.id = 'stress-start';
-    stressStart.textContent = 'atlas stress start';
-    stressStart.addEventListener('click', () => this._stress());
-    stressDiv.appendChild(stressStart);
-
-    const stressStop = document.createElement('button');
-    stressStop.id = 'stress-stop';
-    stressStop.textContent = 'atlas stress stop';
-    stressStop.addEventListener('click', () => this._stressRunning = false);
-    stressDiv.appendChild(stressStop);
-
-    this._stressScrolling = document.createElement('input');
-    this._stressScrolling.type = 'checkbox';
-    this._stressScrolling.id = 'stress-scrolling';
-    stressDiv.appendChild(this._stressScrolling);
-    const stressScrollingLabel = document.createElement('label');
-    stressScrollingLabel.htmlFor = 'stress-scrolling';
-    stressScrollingLabel.textContent = 'stress scrolling';
-    stressDiv.appendChild(stressScrollingLabel);
-    container.appendChild(stressDiv);
-
     const zoomCheckbox = document.createElement('input');
     zoomCheckbox.type = 'checkbox';
     zoomCheckbox.id = 'texture-atlas-zoom';
@@ -73,33 +48,4 @@ export class WebglWindow extends BaseWindow implements IControlWindow {
     canvas.style.width = `${canvas.width / dpr}px`;
     canvas.style.height = `${canvas.height / dpr}px`;
   }
-
-  private async _stress(): Promise<void> {
-    const TEXT = '!"#$%&\'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_`abcdefghijklmnopqrstuvwxyz{|}~';
-    if (this._stressRunning) {
-      return;
-    }
-    this._stressRunning = true;
-    const scrolling = !!(this._stressScrolling?.checked);
-    for (let r = 0; r < 256; r += 2) {
-      for (let g = 0; g < 256; g += 2) {
-        let s: string[] = [];
-        for (let b = 0; b < 256; b += 2) {
-          if (!this._stressRunning) {
-            return;
-          }
-          const rbg = `RGB: ${[r, g, b]}`;
-          s.push(`\r\x1b[38;2;${r};${g};${b}m${rbg.padEnd(18, ' ')}${TEXT}`);
-          if (s.length >= 16) {
-            if (scrolling) {
-              await new Promise<void>(r => this._terminal.write(s.join('\r\n') + '\r\n', r));
-            } else {
-              await new Promise<void>(r => this._terminal.write('\x1b[H' + s.join('\r\n'), r));
-            }
-            s = [];
-          }
-        }
-      }
-    }
-  }
 }

package-lock.json

@@ -6689,6 +6689,16 @@
         "url": "https://github.com/sponsors/ljharb"
       }
     },
+    "node_modules/randombytes": {
+      "version": "2.1.0",
+      "resolved": "https://registry.npmjs.org/randombytes/-/randombytes-2.1.0.tgz",
+      "integrity": "sha512-vYl3iOX+4CKUWuxGi9Ukhie6fsqXqS9FE2Zaic4tNFD2N2QQaXOMFbuKK4QmDHC0JO6B1Zp41J0LpT0oR68amQ==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "safe-buffer": "^5.1.0"
+      }
+    },
     "node_modules/range-parser": {
       "version": "1.2.1",
       "resolved": "https://registry.npmjs.org/range-parser/-/range-parser-1.2.1.tgz",
@@ -6922,6 +6932,27 @@
         "tslib": "^2.1.0"
       }
     },
+    "node_modules/safe-buffer": {
+      "version": "5.2.1",
+      "resolved": "https://registry.npmjs.org/safe-buffer/-/safe-buffer-5.2.1.tgz",
+      "integrity": "sha512-rp3So07KcdmmKbGvgaNxQSJr7bGVSVk5S9Eq1F+ppbRo70+YeaDxkw5Dd8NPN+GD6bjnYm2VuPuCXmpuYvmCXQ==",
+      "dev": true,
+      "funding": [
+        {
+          "type": "github",
+          "url": "https://github.com/sponsors/feross"
+        },
+        {
+          "type": "patreon",
+          "url": "https://www.patreon.com/feross"
+        },
+        {
+          "type": "consulting",
+          "url": "https://feross.org/support"
+        }
+      ],
+      "license": "MIT"
+    },
     "node_modules/safer-buffer": {
       "version": "2.1.2",
       "resolved": "https://registry.npmjs.org/safer-buffer/-/safer-buffer-2.1.2.tgz",
@@ -7047,13 +7078,13 @@
       }
     },
     "node_modules/serialize-javascript": {
-      "version": "7.0.5",
-      "resolved": "https://registry.npmjs.org/serialize-javascript/-/serialize-javascript-7.0.5.tgz",
-      "integrity": "sha512-F4LcB0UqUl1zErq+1nYEEzSHJnIwb3AF2XWB94b+afhrekOUijwooAYqFyRbjYkm2PAKBabx6oYv/xDxNi8IBw==",
+      "version": "6.0.2",
+      "resolved": "https://registry.npmjs.org/serialize-javascript/-/serialize-javascript-6.0.2.tgz",
+      "integrity": "sha512-Saa1xPByTTq2gdeFZYLLo+RFE35NHZkAbqZeWNd3BpzppeVisAqpDjcp8dyf6uIvEqJRd46jemmyA4iFIeVk8g==",
       "dev": true,
       "license": "BSD-3-Clause",
-      "engines": {
-        "node": ">=20.0.0"
+      "dependencies": {
+        "randombytes": "^2.1.0"
       }
     },
     "node_modules/serve-static": {

package.json

@@ -11,9 +11,6 @@
   "workspaces": [
     "addons/*"
   ],
-  "overrides": {
-    "serialize-javascript": "^7.0.3"
-  },
   "keywords": [
     "cli",
     "command-line",
@@ -64,9 +61,9 @@
     "test-integration-firefox": "node ./bin/test_integration.js --workers=75% \"--project=FirefoxStable\"",
     "test-integration-webkit": "node ./bin/test_integration.js --workers=75% \"--project=WebKit\"",
     "test-integration-debug": "node ./bin/test_integration.js  --workers=1 --headed --timeout=30000",
-    "benchmark": "NODE_PATH=./out xterm-benchmark -r 5 -c test/benchmark/benchmark.json",
-    "benchmark-baseline": "NODE_PATH=./out xterm-benchmark -r 5 -c test/benchmark/benchmark.json --baseline out-test/benchmark/*benchmark.js",
-    "benchmark-eval": "NODE_PATH=./out xterm-benchmark -r 5 -c test/benchmark/benchmark.json --eval out-test/benchmark/*benchmark.js",
+    "benchmark": "xterm-benchmark -r 5 -c test/benchmark/benchmark.json",
+    "benchmark-baseline": "xterm-benchmark -r 5 -c test/benchmark/benchmark.json --baseline out-test/benchmark/*benchmark.js",
+    "benchmark-eval": "xterm-benchmark -r 5 -c test/benchmark/benchmark.json --eval out-test/benchmark/*benchmark.js",
     "clean": "rm -rf lib out addons/*/lib addons/*/out",
     "vtfeatures": "node bin/extract_vtfeatures.js src/*/*.ts src/*/*/*.ts src/*.ts addons/**/src/*.ts",
     "prepackage": "npm run build",

src/browser/CoreBrowserTerminal.ts

@@ -102,7 +102,7 @@ export class CoreBrowserTerminal extends CoreTerminal implements ITerminal {
   private _keyDownHandled: boolean = false;
 
   /**
-   * Records whether a keydown event has occurred since the last keyup event, i.e. whether a key
+   * Records whether a keydown event has occured since the last keyup event, i.e. whether a key
    * is currently "pressed".
    */
   private _keyDownSeen: boolean = false;
@@ -1072,6 +1072,10 @@ export class CoreBrowserTerminal extends CoreTerminal implements ITerminal {
    * Clear the entire buffer, making the prompt line the new first line.
    */
   public clear(): void {
+    if (this.buffer.ybase === 0 && this.buffer.y === 0) {
+      // Don't clear if it's already clear
+      return;
+    }
     this.buffer.clearAllMarkers();
     this.buffer.lines.set(0, this.buffer.lines.get(this.buffer.ybase + this.buffer.y)!);
     this.buffer.lines.length = 1;

src/browser/RenderDebouncer.ts

@@ -31,7 +31,9 @@ export class RenderDebouncer implements IRenderDebouncerWithCallback {
 
   public addRefreshCallback(callback: FrameRequestCallback): number {
     this._refreshCallbacks.push(callback);
-    this._animationFrame ??= this._coreBrowserService.window.requestAnimationFrame(() => this._innerRefresh());
+    if (this._animationFrame === undefined) {
+      this._animationFrame = this._coreBrowserService.window.requestAnimationFrame(() => this._innerRefresh());
+    }
     return this._animationFrame;
   }
 

src/browser/input/Mouse.ts

@@ -31,7 +31,7 @@ export function getCoordsRelativeToElement(window: Pick<Window, 'getComputedStyl
  * select that cell and the right half will select the next cell.
  */
 export function getCoords(window: Pick<Window, 'getComputedStyle'>, event: Pick<MouseEvent, 'clientX' | 'clientY'>, element: HTMLElement, colCount: number, rowCount: number, hasValidCharSize: boolean, cssCellWidth: number, cssCellHeight: number, isSelection?: boolean): [number, number] | undefined {
-  // Coordinates cannot be measured if there is no valid character size.
+  // Coordinates cannot be measured if there are no valid
   if (!hasValidCharSize) {
     return undefined;
   }
@@ -41,7 +41,7 @@ export function getCoords(window: Pick<Window, 'getComputedStyle'>, event: Pick<
   coords[1] = Math.ceil(coords[1] / cssCellHeight);
 
   // Ensure coordinates are within the terminal viewport. Note that selections
-  // need an additional point of precision to cover the end point (as characters
+  // need an addition point of precision to cover the end point (as characters
   // cover half of one char and half of the next).
   coords[0] = Math.min(Math.max(coords[0], 1), colCount + (isSelection ? 1 : 0));
   coords[1] = Math.min(Math.max(coords[1], 1), rowCount);

src/browser/renderer/dom/DomRenderer.ts

@@ -536,14 +536,9 @@ export class DomRenderer extends Disposable implements IRenderer {
     for (let y = start; y <= end; y++) {
       const row = y + buffer.ydisp;
       const rowElement = this._rowElements[y];
-      if (!rowElement) {
-        continue;
-      }
       const lineData = buffer.lines.get(row);
-      if (!lineData) {
-        rowElement.replaceChildren();
-        this._setRowBlinkState(y, false);
-        continue;
+      if (!rowElement || !lineData) {
+        break;
       }
       rowElement.replaceChildren(
         ...this._rowFactory.createRow(
@@ -615,14 +610,9 @@ export class DomRenderer extends Disposable implements IRenderer {
     for (let i = y; i <= y2; ++i) {
       const row = i + buffer.ydisp;
       const rowElement = this._rowElements[i];
-      if (!rowElement) {
-        continue;
-      }
       const bufferline = buffer.lines.get(row);
-      if (!bufferline) {
-        rowElement.replaceChildren();
-        this._setRowBlinkState(i, false);
-        continue;
+      if (!rowElement || !bufferline) {
+        break;
       }
       rowElement.replaceChildren(
         ...this._rowFactory.createRow(

src/browser/selection/SelectionModel.test.ts

@@ -64,13 +64,6 @@ describe('SelectionModel', () => {
       assert.deepEqual(model.finalSelectionStart, undefined);
       assert.deepEqual(model.finalSelectionEnd, undefined);
     });
-    it('should reset selection start to origin when start row is trimmed', () => {
-      model.selectionStart = [50, 0];
-      model.selectionEnd = [10, 2];
-      assert.equal(model.handleTrim(1), true);
-      assert.deepEqual(model.finalSelectionStart, [0, 0]);
-      assert.deepEqual(model.finalSelectionEnd, [10, 1]);
-    });
   });
 
   describe('finalSelectionStart', () => {

src/browser/selection/SelectionModel.ts

@@ -135,10 +135,9 @@ export class SelectionModel {
       return true;
     }
 
-    // If the selection start row is trimmed away, reset to the buffer origin.
+    // If the selection start is trimmed, ensure the start column is 0.
     if (this.selectionStart && this.selectionStart[1] < 0) {
-      this.selectionStart = [0, 0];
-      return true;
+      this.selectionStart[1] = 0;
     }
     return false;
   }

src/browser/services/CharacterJoinerService.ts

@@ -100,7 +100,6 @@ export class CharacterJoinerService implements ICharacterJoinerService {
 
     const ranges: [number, number][] = [];
     const lineStr = line.translateToString(true);
-    const trimmedLength = line.getTrimmedLength();
 
     // Because some cells can be represented by multiple javascript characters,
     // we track the cell and the string indexes separately. This allows us to
@@ -112,7 +111,7 @@ export class CharacterJoinerService implements ICharacterJoinerService {
     let rangeAttrFG = line.getFg(0);
     let rangeAttrBG = line.getBg(0);
 
-    for (let x = 0; x < trimmedLength; x++) {
+    for (let x = 0; x < line.getTrimmedLength(); x++) {
       line.loadCell(x, this._workCell);
 
       if (this._workCell.getWidth() === 0) {
@@ -148,7 +147,7 @@ export class CharacterJoinerService implements ICharacterJoinerService {
     }
 
     // Process any trailing ranges.
-    if (trimmedLength - rangeStartColumn > 1) {
+    if (this._bufferService.cols - rangeStartColumn > 1) {
       const joinedRanges = this._getJoinedRanges(
         lineStr,
         rangeStartStringIndex,
@@ -217,8 +216,7 @@ export class CharacterJoinerService implements ICharacterJoinerService {
       return;
     }
 
-    const trimmedLength = line.getTrimmedLength();
-    for (let x = startCol; x < trimmedLength; x++) {
+    for (let x = startCol; x < this._bufferService.cols; x++) {
       const width = line.getWidth(x);
       const length = line.getString(x).length || WHITESPACE_CELL_CHAR.length;
 
@@ -266,7 +264,7 @@ export class CharacterJoinerService implements ICharacterJoinerService {
     // If there is still a range left at the end, it must extend all the way to
     // the end of the line.
     if (currentRange) {
-      currentRange[1] = trimmedLength;
+      currentRange[1] = this._bufferService.cols;
     }
   }
 

src/browser/services/MouseService.test.ts

@@ -176,7 +176,7 @@ describe('MouseService _triggerMouseEvent', () => {
       for (let i = 0; i < bufferService.cols; ++i) {
         assert.equal(trigger({ col: i, row: 0, x: 0, y: 0, button: CoreMouseButton.LEFT, action: CoreMouseAction.DOWN }), true);
         if (i > 222) {
-          // suppress mouse reports if we are out of addressable range (max. 222)
+          // supress mouse reports if we are out of addressible range (max. 222)
           assert.deepEqual(toBytes(reports.pop()), []);
         } else {
           assert.deepEqual(toBytes(reports.pop()), [0x1b, 0x5b, 0x4d, 0x20, i + 33, 0x21]);

src/browser/services/SelectionService.ts

@@ -704,7 +704,7 @@ export class SelectionService extends Disposable implements ISelectionService {
         if (this._activeSelectionMode !== SelectionMode.COLUMN) {
           this._model.selectionEnd[0] = this._bufferService.cols;
         }
-        this._model.selectionEnd[1] = Math.min(buffer.ydisp + this._bufferService.rows - 1, buffer.lines.length - 1);
+        this._model.selectionEnd[1] = Math.min(buffer.ydisp + this._bufferService.rows, buffer.lines.length - 1);
       } else {
         if (this._activeSelectionMode !== SelectionMode.COLUMN) {
           this._model.selectionEnd[0] = 0;

src/browser/services/ThemeService.ts

@@ -132,7 +132,7 @@ export class ThemeService extends Disposable implements IThemeService {
         colors.ansi[i + 16] = parseColor(theme.extendedAnsi[i], DEFAULT_ANSI_COLORS[i + 16]);
       }
     }
-    // Clear the cache
+    // Clear our the cache
     this._contrastCache.clear();
     this._halfContrastCache.clear();
     this._updateRestoreColors();

src/common/Color.ts

@@ -373,7 +373,7 @@ export function toPaddedHex(c: number): string {
 /**
  * Gets the contrast ratio between two relative luminance values.
  * @param l1 The first relative luminance.
- * @param l2 The second relative luminance.
+ * @param l2 The first relative luminance.
  * @see https://www.w3.org/TR/WCAG20/#contrast-ratiodef
  */
 export function contrastRatio(l1: number, l2: number): number {

src/common/InputHandler.test.ts

@@ -16,10 +16,8 @@ import { MockCoreService, MockBufferService, MockOptionsService, MockLogService,
 import { IBufferService, ICoreService, type IOscLinkService } from './services/Services';
 import { DEFAULT_OPTIONS } from './services/OptionsService';
 import { BufferService } from './services/BufferService';
-import { CharsetService } from './services/CharsetService';
 import { CoreService } from './services/CoreService';
 import { OscLinkService } from './services/OscLinkService';
-import { CHARSETS } from './data/Charsets';
 
 
 function getCursor(bufferService: IBufferService): number[] {
@@ -641,38 +639,19 @@ describe('InputHandler', () => {
   });
   describe('print', () => {
     it('should not cause an infinite loop (regression test)', () => {
+      const inputHandler = new TestInputHandler(
+        new MockBufferService(80, 30),
+        new MockCharsetService(),
+        new MockCoreService(),
+        new MockLogService(),
+        new MockOptionsService(),
+        new MockOscLinkService(),
+        new MockMouseStateService(),
+        new MockUnicodeService()
+      );
       const container = new Uint32Array(10);
       container[0] = 0x200B;
-      const lineCountBefore = bufferService.buffer.lines.length;
       inputHandler.print(container, 0, 1);
-      assert.strictEqual(bufferService.buffer.y, 0);
-      assert.strictEqual(bufferService.buffer.lines.length, lineCountBefore);
-    });
-    it('should join combining characters in a single print', async () => {
-      await inputHandler.parseP('e\u0301');
-      assert.strictEqual(bufferService.buffer.translateBufferLineToString(0, true), 'e\u0301');
-      assert.strictEqual(bufferService.buffer.x, 1);
-    });
-    it('should join combining characters split across parse calls', async () => {
-      await inputHandler.parseP('e');
-      await inputHandler.parseP('\u0301');
-      assert.strictEqual(bufferService.buffer.translateBufferLineToString(0, true), 'e\u0301');
-      assert.strictEqual(bufferService.buffer.x, 1);
-    });
-    it('should repeat preceding grapheme cluster via REP', async () => {
-      await inputHandler.parseP('e\u0301\x1b[2b');
-      assert.strictEqual(bufferService.buffer.translateBufferLineToString(0, true), 'e\u0301e\u0301e\u0301');
-      assert.strictEqual(bufferService.buffer.x, 3);
-    });
-    it('should not repeat when REP has no preceding join state', async () => {
-      await inputHandler.parseP('\x1b[2b');
-      assert.strictEqual(bufferService.buffer.translateBufferLineToString(0, true), '');
-      assert.strictEqual(bufferService.buffer.x, 0);
-    });
-    it('should not repeat after an intervening escape sequence', async () => {
-      await inputHandler.parseP('a\x1b[0m\x1b[2b');
-      assert.strictEqual(bufferService.buffer.translateBufferLineToString(0, true), 'a');
-      assert.strictEqual(bufferService.buffer.x, 1);
     });
     it('should clear cells to the right on early wrap-around', async () => {
       bufferService.resize(5, 5);
@@ -689,49 +668,6 @@ describe('InputHandler', () => {
     });
   });
 
-  describe('ISO-2022 character sets', () => {
-    let charsetService: CharsetService;
-
-    beforeEach(() => {
-      charsetService = new CharsetService();
-      inputHandler = new TestInputHandler(
-        bufferService,
-        charsetService,
-        coreService,
-        new MockLogService(),
-        optionsService,
-        oscLinkService,
-        new MockMouseStateService(),
-        new MockUnicodeService()
-      );
-    });
-
-    it('should map G0 line drawing via ESC ( 0', async () => {
-      await inputHandler.parseP('\x1b(0q\x1b(Bq');
-      assert.strictEqual(bufferService.buffer.translateBufferLineToString(0, true), '\u2500q');
-    });
-
-    it('should map G1 line drawing after ESC ) 0 and SO', async () => {
-      await inputHandler.parseP('\x1b)0\x0eq\x0f\x1b(Bq');
-      assert.strictEqual(bufferService.buffer.translateBufferLineToString(0, true), '\u2500q');
-    });
-
-    it('should restore charset and glevel on ESC 7 / ESC 8', async () => {
-      await inputHandler.parseP('\x1b)0\x0e');
-      assert.strictEqual(charsetService.glevel, 1);
-      assert.strictEqual(charsetService.charset, CHARSETS['0']);
-      await inputHandler.parseP('\x1b7');
-      await inputHandler.parseP('\x0f\x1b(B');
-      assert.strictEqual(charsetService.glevel, 0);
-      assert.ok(charsetService.charset === undefined);
-      await inputHandler.parseP('\x1b8');
-      assert.strictEqual(charsetService.glevel, 1);
-      assert.strictEqual(charsetService.charset, CHARSETS['0']);
-      await inputHandler.parseP('q');
-      assert.strictEqual(bufferService.buffer.translateBufferLineToString(0, true), '\u2500');
-    });
-  });
-
   describe('alt screen', () => {
     let bufferService: IBufferService;
     let handler: TestInputHandler;
@@ -1246,19 +1182,6 @@ describe('InputHandler', () => {
       await inputHandler.parseP('\x1b[100;100H');
       assert.deepEqual(getCursor(bufferService), [9, 9]);
     });
-    it('cursor position (CUP) with DECOM and scroll margins', async () => {
-      await inputHandler.parseP('\x1b[?6h\x1b[2;3r\x1b[1;1H');
-      assert.deepEqual(getCursor(bufferService), [0, 1]);
-      await inputHandler.parseP('X');
-      assert.strictEqual(getLines(bufferService, 3)[1], 'X');
-      await inputHandler.parseP('\x1b[2;1H');
-      assert.deepEqual(getCursor(bufferService), [0, 2]);
-      await inputHandler.parseP('\x1b[10;10H');
-      assert.deepEqual(getCursor(bufferService), [9, 2]);
-      await inputHandler.parseP('\x1b[?6l');
-      await inputHandler.parseP('\x1b[2;1H');
-      assert.deepEqual(getCursor(bufferService), [0, 1]);
-    });
     it('horizontal position absolute (HPA)', async () => {
       await inputHandler.parseP('\x1b[`');
       assert.deepEqual(getCursor(bufferService), [0, 0]);
@@ -1318,7 +1241,7 @@ describe('InputHandler', () => {
       await inputHandler.parseP('\x1b[e');
       assert.deepEqual(getCursor(bufferService), [8, 5]);
     });
-    describe('should clamp cursor into addressable range', () => {
+    describe('should clamp cursor into addressible range', () => {
       it('CUF', async () => {
         bufferService.buffer.x = 10000;
         bufferService.buffer.y = 10000;

src/common/Platform.ts

@@ -44,7 +44,7 @@ export function getSafariVersion(): number {
   return parseInt(majorVersion[1], 10);
 }
 
-// Find the user's platform. We use this to interpret the meta key
+// Find the users platform. We use this to interpret the meta key
 // and ISO third level shifts.
 // http://stackoverflow.com/q/19877924/577598
 export const isMac = ['Macintosh', 'MacIntel', 'MacPPC', 'Mac68K'].includes(platform);

src/common/TaskQueue.ts

@@ -8,7 +8,7 @@ import type { ILogService } from './services/Services';
 interface ITaskQueue {
   /**
    * Adds a task to the queue which will run in a future idle callback.
-   * To avoid perceivable stalls on the main thread, tasks with heavy workload
+   * To avoid perceivable stalls on the mainthread, tasks with heavy workload
    * should split their work into smaller pieces and return `true` to get
    * called again until the work is done (on falsy return value).
    */

src/common/Types.ts

@@ -181,7 +181,7 @@ export interface ICoreMouseEvent {
   x: number;
   y: number;
   /**
-   * Button the action occurred. Due to restrictions of the tracking protocols
+   * Button the action occured. Due to restrictions of the tracking protocols
    * it is not possible to report multiple buttons at once.
    * Wheel is treated as a button.
    * There are invalid combinations of buttons and actions possible

src/common/WindowsMode.test.ts

@@ -1,54 +0,0 @@
-/**
- * Copyright (c) 2026 The xterm.js authors. All rights reserved.
- * @license MIT
- */
-
-import { assert } from 'chai';
-import { DEFAULT_ATTR_DATA } from './buffer/BufferLine';
-import { updateWindowsModeWrappedState } from './WindowsMode';
-import { BufferService } from './services/BufferService';
-import { OptionsService } from './services/OptionsService';
-import { MockLogService } from './TestUtils.test';
-
-describe('WindowsMode', () => {
-  describe('updateWindowsModeWrappedState', () => {
-    it('should mark the next line wrapped when the previous line ends in a non-whitespace character', () => {
-      const bufferService = new BufferService(new OptionsService({ rows: 5, cols: 10 }), new MockLogService());
-      const buffer = bufferService.buffer;
-      const previousLine = buffer.lines.get(buffer.ybase)!;
-      for (let i = 0; i < bufferService.cols; i++) {
-        previousLine!.setCellFromCodepoint(i, 'a'.charCodeAt(0), 1, DEFAULT_ATTR_DATA);
-      }
-      buffer.y = 1;
-
-      updateWindowsModeWrappedState(bufferService);
-
-      assert.strictEqual(buffer.lines.get(buffer.ybase + 1)!.isWrapped, true);
-    });
-
-    it('should not mark the next line wrapped when the previous line ends in whitespace', () => {
-      const bufferService = new BufferService(new OptionsService({ rows: 5, cols: 10 }), new MockLogService());
-      const buffer = bufferService.buffer;
-      const previousLine = buffer.lines.get(buffer.ybase)!;
-      for (let i = 0; i < bufferService.cols - 1; i++) {
-        previousLine!.setCellFromCodepoint(i, 'a'.charCodeAt(0), 1, DEFAULT_ATTR_DATA);
-      }
-      previousLine!.setCellFromCodepoint(bufferService.cols - 1, ' '.charCodeAt(0), 1, DEFAULT_ATTR_DATA);
-      buffer.y = 1;
-
-      updateWindowsModeWrappedState(bufferService);
-
-      assert.strictEqual(buffer.lines.get(buffer.ybase + 1)!.isWrapped, false);
-    });
-
-    it('should not mark the next line wrapped when the previous line ends in a null cell', () => {
-      const bufferService = new BufferService(new OptionsService({ rows: 5, cols: 10 }), new MockLogService());
-      const buffer = bufferService.buffer;
-      buffer.y = 1;
-
-      updateWindowsModeWrappedState(bufferService);
-
-      assert.strictEqual(buffer.lines.get(buffer.ybase + 1)!.isWrapped, false);
-    });
-  });
-});

src/common/buffer/Buffer.test.ts

@@ -233,27 +233,6 @@ describe('Buffer', () => {
           assert.equal(buffer.lines.length, INIT_ROWS + 10);
         });
       });
-
-      describe('Windows ConPTY', () => {
-        beforeEach(() => {
-          optionsService.options.windowsPty = { backend: 'conpty', buildNumber: 19000 };
-        });
-
-        it('should not adjust ybase or ydisp when growing rows', () => {
-          buffer.fillViewportRows();
-          for (let i = 0; i < 10; i++) {
-            buffer.lines.push(buffer.getBlankLine(DEFAULT_ATTR_DATA));
-          }
-          buffer.y = INIT_ROWS - 1;
-          buffer.ybase = 10;
-          buffer.ydisp = 10;
-          const linesBefore = buffer.lines.length;
-          buffer.resize(INIT_COLS, INIT_ROWS + 5);
-          assert.equal(buffer.ybase, 10);
-          assert.equal(buffer.ydisp, 10);
-          assert.equal(buffer.lines.length, linesBefore + 5);
-        });
-      });
     });
 
     describe('row and column increased', () => {
@@ -326,71 +305,6 @@ describe('Buffer', () => {
         assert.equal(buffer.lines.get(8)!.translateToString(), '     ');
         assert.equal(buffer.lines.get(9)!.translateToString(), '     ');
       });
-      it('should gate reflow on ConPTY buildNumber 21376', () => {
-        const prepareWrappedShrink = () => {
-          buffer.fillViewportRows();
-          buffer.resize(5, 10);
-          const firstLine = buffer.lines.get(0)!;
-          for (let i = 0; i < 5; i++) {
-            const code = 'a'.charCodeAt(0) + i;
-            firstLine.set(i, [0, String.fromCharCode(code), 1, code]);
-          }
-          buffer.y = 1;
-          buffer.resize(1, 10);
-        };
-
-        optionsService.options.windowsPty = { backend: 'conpty', buildNumber: 21375 };
-        prepareWrappedShrink();
-        assert.equal(buffer.lines.get(1)!.translateToString().trim(), '');
-
-        buffer = new TestBuffer(true, optionsService, bufferService, new MockLogService());
-        optionsService.options.windowsPty = { backend: 'conpty', buildNumber: 21376 };
-        prepareWrappedShrink();
-        assert.equal(buffer.lines.get(1)!.translateToString().trim(), 'b');
-        assert.ok(buffer.lines.get(1)!.isWrapped);
-      });
-      it('should unwrap lines on ConPTY builds with reflow support', () => {
-        optionsService.options.windowsPty = { backend: 'conpty', buildNumber: 21376 };
-        buffer.fillViewportRows();
-        buffer.resize(5, 10);
-        const firstLine = buffer.lines.get(0)!;
-        for (let i = 0; i < 5; i++) {
-          const code = 'a'.charCodeAt(0) + i;
-          firstLine.set(i, [0, String.fromCharCode(code), 1, code]);
-        }
-        buffer.y = 1;
-        buffer.resize(1, 10);
-        buffer.resize(5, 10);
-        assert.equal(buffer.lines.get(0)!.translateToString(), 'abcde');
-        assert.equal(buffer.lines.get(1)!.translateToString(), '     ');
-      });
-      it('should reflow wrapped lines containing the cursor when reflowCursorLine is enabled', () => {
-        optionsService.options.reflowCursorLine = true;
-        buffer.fillViewportRows();
-        buffer.resize(5, 10);
-        const firstLine = buffer.lines.get(0)!;
-        for (let i = 0; i < 5; i++) {
-          const code = 'a'.charCodeAt(0) + i;
-          firstLine.set(i, [0, String.fromCharCode(code), 1, code]);
-        }
-        buffer.resize(1, 10);
-        buffer.y = 2;
-        buffer.resize(5, 10);
-        assert.equal(buffer.lines.get(0)!.translateToString(), 'abcde');
-      });
-      it('should not reflow wrapped lines containing the cursor by default', () => {
-        buffer.fillViewportRows();
-        buffer.resize(5, 10);
-        const firstLine = buffer.lines.get(0)!;
-        for (let i = 0; i < 5; i++) {
-          const code = 'a'.charCodeAt(0) + i;
-          firstLine.set(i, [0, String.fromCharCode(code), 1, code]);
-        }
-        buffer.resize(1, 10);
-        buffer.y = 2;
-        buffer.resize(5, 10);
-        assert.notEqual(buffer.lines.get(0)!.translateToString(), 'abcde');
-      });
       it('should discard parts of wrapped lines that go out of the scrollback', () => {
         buffer.fillViewportRows();
         optionsService.options.scrollback = 1;

src/common/buffer/Buffer.ts

@@ -142,7 +142,7 @@ export class Buffer extends Disposable implements IBuffer {
   }
 
   /**
-   * Clears the buffer to its initial state, discarding all previous data.
+   * Clears the buffer to it's initial state, discarding all previous data.
    */
   public clear(): void {
     this._stringCache.clear();
@@ -197,7 +197,7 @@ export class Buffer extends Disposable implements IBuffer {
         for (let y = this._rows; y < newRows; y++) {
           if (this.lines.length < newRows + this.ybase) {
             if (this._optionsService.rawOptions.windowsPty.backend !== undefined || this._optionsService.rawOptions.windowsPty.buildNumber !== undefined) {
-              // Just add the new missing rows on Windows as conpty reprints the screen with its
+              // Just add the new missing rows on Windows as conpty reprints the screen with it's
               // view of the world. Once a line enters scrollback for conpty it remains there
               this.lines.push(new BufferLine(this._stringCache, newCols, nullCell, false));
             } else {

src/common/buffer/BufferLine.ts

@@ -71,20 +71,10 @@ export interface IBufferLineStringCache {
  * (if only one particular value is needed) or `loadCell`. For `loadCell` in a loop
  * memory allocs / GC pressure can be greatly reduced by reusing the CellData object.
  */
-/**
- * Shared empty sparse map for lines with no combining data.
- * Uses a sentinel + copy-on-write so `copyFrom` can detect empty `_combined` with
- * reference equality. `_extendedAttrs` uses `undefined` instead (addon-image writes
- * the map directly without BufferLine APIs).
- */
-const EMPTY_SPARSE_MAP: {[index: number]: string} = Object.create(null);
-
 export class BufferLine implements IBufferLine {
   protected _data: Uint32Array;
-  /** Sparse cache; only read when `IS_COMBINED_MASK` is set in `_data`. */
-  protected _combined: {[index: number]: string} = EMPTY_SPARSE_MAP;
-  /** Sparse cache; only read when `HAS_EXTENDED` is set in `_data`. */
-  protected _extendedAttrs: {[index: number]: IExtendedAttrs | undefined} | undefined;
+  protected _combined: {[index: number]: string} = {};
+  protected _extendedAttrs: {[index: number]: IExtendedAttrs | undefined} = {};
   protected _stringCacheEntryRef: WeakRef<IBufferLineStringCacheEntry> | undefined;
   public length: number;
 
@@ -129,7 +119,6 @@ export class BufferLine implements IBufferLine {
     this._invalidateStringCache();
     this._data[index * Constants.CELL_INDICIES + Cell.FG] = value[CHAR_DATA_ATTR_INDEX];
     if (value[CHAR_DATA_CHAR_INDEX].length > 1) {
-      this._ensureCombinedMap();
       this._combined[index] = value[1];
       this._data[index * Constants.CELL_INDICIES + Cell.CONTENT] = index | Content.IS_COMBINED_MASK | (value[CHAR_DATA_WIDTH_INDEX] << Content.WIDTH_SHIFT);
     } else {
@@ -216,15 +205,9 @@ export class BufferLine implements IBufferLine {
     cell.bg = this._data[$startIndex + Cell.BG];
     if (cell.content & Content.IS_COMBINED_MASK) {
       cell.combinedData = this._combined[index];
-    } else {
-      cell.combinedData = '';
     }
     if (cell.bg & BgFlags.HAS_EXTENDED) {
-      cell.extended = this._extendedAttrs![index]!;
-    } else {
-      // Do not mutate cell.extended in place: it may still reference this line's map entry from a
-      // prior loadCell into a reused CellData (e.g. $workCell during insert/delete).
-      cell.extended = DEFAULT_ATTR_DATA.extended.clone();
+      cell.extended = this._extendedAttrs[index]!;
     }
     return cell;
   }
@@ -235,11 +218,10 @@ export class BufferLine implements IBufferLine {
   public setCell(index: number, cell: ICellData): void {
     this._invalidateStringCache();
     if (cell.content & Content.IS_COMBINED_MASK) {
-      this._ensureCombinedMap();
       this._combined[index] = cell.combinedData;
     }
     if (cell.bg & BgFlags.HAS_EXTENDED) {
-      this._ensureExtendedAttrsMap()[index] = cell.extended;
+      this._extendedAttrs[index] = cell.extended;
     }
     this._data[index * Constants.CELL_INDICIES + Cell.CONTENT] = cell.content;
     this._data[index * Constants.CELL_INDICIES + Cell.FG] = cell.fg;
@@ -254,7 +236,7 @@ export class BufferLine implements IBufferLine {
   public setCellFromCodepoint(index: number, codePoint: number, width: number, attrs: IAttributeData): void {
     this._invalidateStringCache();
     if (attrs.bg & BgFlags.HAS_EXTENDED) {
-      this._ensureExtendedAttrsMap()[index] = attrs.extended;
+      this._extendedAttrs[index] = attrs.extended;
     }
     this._data[index * Constants.CELL_INDICIES + Cell.CONTENT] = codePoint | (width << Content.WIDTH_SHIFT);
     this._data[index * Constants.CELL_INDICIES + Cell.FG] = attrs.fg;
@@ -272,14 +254,12 @@ export class BufferLine implements IBufferLine {
     let content = this._data[index * Constants.CELL_INDICIES + Cell.CONTENT];
     if (content & Content.IS_COMBINED_MASK) {
       // we already have a combined string, simply add
-      this._ensureCombinedMap();
       this._combined[index] += stringFromCodePoint(codePoint);
     } else {
       if (content & Content.CODEPOINT_MASK) {
         // normal case for combining chars:
         //  - move current leading char + new one into combined string
         //  - set combined flag
-        this._ensureCombinedMap();
         this._combined[index] = stringFromCodePoint(content & Content.CODEPOINT_MASK) + stringFromCodePoint(codePoint);
         content &= ~Content.CODEPOINT_MASK; // set codepoint in buffer to 0
         content |= Content.IS_COMBINED_MASK;
@@ -422,13 +402,11 @@ export class BufferLine implements IBufferLine {
         }
       }
       // remove any cut off extended attributes
-      if (this._extendedAttrs) {
-        const extKeys = Object.keys(this._extendedAttrs);
-        for (let i = 0; i < extKeys.length; i++) {
-          const key = parseInt(extKeys[i], 10);
-          if (key >= cols) {
-            delete this._extendedAttrs[key];
-          }
+      const extKeys = Object.keys(this._extendedAttrs);
+      for (let i = 0; i < extKeys.length; i++) {
+        const key = parseInt(extKeys[i], 10);
+        if (key >= cols) {
+          delete this._extendedAttrs[key];
         }
       }
     }
@@ -464,8 +442,8 @@ export class BufferLine implements IBufferLine {
       }
       return;
     }
-    this._combined = EMPTY_SPARSE_MAP;
-    this._extendedAttrs = undefined;
+    this._combined = {};
+    this._extendedAttrs = {};
     for (let i = 0; i < this.length; ++i) {
       this.setCell(i, fillCellData);
     }
@@ -481,7 +459,14 @@ export class BufferLine implements IBufferLine {
       this._data.set(line._data);
     }
     this.length = line.length;
-    this._copySparseMapsFrom(line);
+    this._combined = {};
+    for (const el in line._combined) {
+      this._combined[el] = line._combined[el];
+    }
+    this._extendedAttrs = {};
+    for (const el in line._extendedAttrs) {
+      this._extendedAttrs[el] = line._extendedAttrs[el];
+    }
     this.isWrapped = line.isWrapped;
   }
 
@@ -490,7 +475,12 @@ export class BufferLine implements IBufferLine {
     const newLine = new BufferLine(this._stringCache, 0, undefined, false);
     newLine._data = new Uint32Array(this._data);
     newLine.length = this.length;
-    newLine._copySparseMapsFrom(this);
+    for (const el in this._combined) {
+      newLine._combined[el] = this._combined[el];
+    }
+    for (const el in this._extendedAttrs) {
+      newLine._extendedAttrs[el] = this._extendedAttrs[el];
+    }
     newLine.isWrapped = this.isWrapped;
     return newLine;
   }
@@ -521,14 +511,27 @@ export class BufferLine implements IBufferLine {
         for (let i = 0; i < Constants.CELL_INDICIES; i++) {
           this._data[(destCol + cell) * Constants.CELL_INDICIES + i] = srcData[(srcCol + cell) * Constants.CELL_INDICIES + i];
         }
-        this._copyCellMapsFrom(src, srcCol + cell, destCol + cell);
+        if (srcData[(srcCol + cell) * Constants.CELL_INDICIES + Cell.BG] & BgFlags.HAS_EXTENDED) {
+          this._extendedAttrs[destCol + cell] = src._extendedAttrs[srcCol + cell];
+        }
       }
     } else {
       for (let cell = 0; cell < length; cell++) {
         for (let i = 0; i < Constants.CELL_INDICIES; i++) {
           this._data[(destCol + cell) * Constants.CELL_INDICIES + i] = srcData[(srcCol + cell) * Constants.CELL_INDICIES + i];
         }
-        this._copyCellMapsFrom(src, srcCol + cell, destCol + cell);
+        if (srcData[(srcCol + cell) * Constants.CELL_INDICIES + Cell.BG] & BgFlags.HAS_EXTENDED) {
+          this._extendedAttrs[destCol + cell] = src._extendedAttrs[srcCol + cell];
+        }
+      }
+    }
+
+    // Move any combined data over as needed, FIXME: repeat for extended attrs
+    const srcCombinedKeys = Object.keys(src._combined);
+    for (let i = 0; i < srcCombinedKeys.length; i++) {
+      const key = parseInt(srcCombinedKeys[i], 10);
+      if (key >= srcCol) {
+        this._combined[key - srcCol + destCol] = src._combined[key];
       }
     }
   }
@@ -617,62 +620,4 @@ export class BufferLine implements IBufferLine {
       cacheEntry.isTrimmed = false;
     }
   }
-
-  /** Copy sparse map entries for a single cell when `_data` flags require them. */
-  private _copyCellMapsFrom(src: BufferLine, srcCol: number, destCol: number): void {
-    const srcStart = srcCol * Constants.CELL_INDICIES;
-    if (src._data[srcStart + Cell.CONTENT] & Content.IS_COMBINED_MASK) {
-      this._ensureCombinedMap();
-      this._combined[destCol] = src._combined[srcCol];
-    }
-    if (src._data[srcStart + Cell.BG] & BgFlags.HAS_EXTENDED) {
-      this._ensureExtendedAttrsMap()[destCol] = src._extendedAttrs![srcCol]!;
-    }
-  }
-
-  /** Rebuild sparse maps from another line, keyed only by `_data` flags. */
-  private _copySparseMapsFrom(line: BufferLine): void {
-    const srcCombined = line._combined;
-    const srcExtended = line._extendedAttrs;
-
-    // Fast path: blank / scroll-recycle source (empty `_combined` sentinel, no extended map).
-    if (srcCombined === EMPTY_SPARSE_MAP && !srcExtended) {
-      this._combined = EMPTY_SPARSE_MAP;
-      this._extendedAttrs = undefined;
-      return;
-    }
-    this._copySparseMapsFromDense(line);
-  }
-
-  /** Copy sparse maps by scanning `_data` flags (inlined, no per-cell function calls). */
-  private _copySparseMapsFromDense(line: BufferLine): void {
-    this._combined = {};
-    this._extendedAttrs = {};
-    const srcData = line._data;
-    const srcCombined = line._combined;
-    const srcExtended = line._extendedAttrs;
-    const len = line.length;
-    const indices = Constants.CELL_INDICIES;
-    const combined = this._combined;
-    const extendedAttrs = this._extendedAttrs;
-    for (let i = 0; i < len; i++) {
-      const start = i * indices;
-      if (srcData[start + Cell.CONTENT] & Content.IS_COMBINED_MASK) {
-        combined[i] = srcCombined[i];
-      }
-      if (srcData[start + Cell.BG] & BgFlags.HAS_EXTENDED) {
-        extendedAttrs[i] = srcExtended![i];
-      }
-    }
-  }
-
-  private _ensureCombinedMap(): void {
-    if (this._combined === EMPTY_SPARSE_MAP) {
-      this._combined = {};
-    }
-  }
-
-  private _ensureExtendedAttrsMap(): {[index: number]: IExtendedAttrs | undefined} {
-    return this._extendedAttrs ??= {};
-  }
 }

src/common/buffer/BufferReflow.test.ts

@@ -3,13 +3,10 @@
  * @license MIT
  */
 import { assert } from 'chai';
-import { CircularList } from '../CircularList';
 import { BufferLine } from './BufferLine';
 import { BufferLineStringCache } from './BufferLineStringCache';
-import { CellData } from './CellData';
 import { NULL_CELL_CHAR, NULL_CELL_WIDTH, NULL_CELL_CODE } from './Constants';
-import { reflowLargerGetLinesToRemove, reflowSmallerGetNewLineLengths } from './BufferReflow';
-import { IBufferLine } from './Types';
+import { reflowSmallerGetNewLineLengths } from './BufferReflow';
 
 const TEST_STRING_CACHE = new BufferLineStringCache();
 
@@ -96,31 +93,4 @@ describe('BufferReflow', () => {
       assert.deepEqual(reflowSmallerGetNewLineLengths([line], 4, 2), [2, 2], 'line: 汉, 语');
     });
   });
-  describe('reflowLargerGetLinesToRemove', () => {
-    const nullCell = CellData.fromCharData([0, NULL_CELL_CHAR, NULL_CELL_WIDTH, NULL_CELL_CODE]);
-
-    function createWrappedLines(chars: string): CircularList<IBufferLine> {
-      const lines = new CircularList<IBufferLine>(chars.length);
-      for (let i = 0; i < chars.length; i++) {
-        const line = new BufferLine(TEST_STRING_CACHE, 1);
-        line.set(0, [0, chars[i], 1, chars.charCodeAt(i)]);
-        line.isWrapped = i > 0;
-        lines.push(line);
-      }
-      return lines;
-    }
-
-    it('should skip reflow when the cursor is in a wrapped block and reflowCursorLine is false', () => {
-      const lines = createWrappedLines('abcde');
-      const skipped = reflowLargerGetLinesToRemove(lines, 1, 5, 2, nullCell, false);
-      const reflowed = reflowLargerGetLinesToRemove(lines, 1, 5, 2, nullCell, true);
-      assert.deepEqual(skipped, []);
-      assert.notDeepEqual(reflowed, []);
-    });
-
-    it('should reflow wrapped blocks when the cursor is outside the block', () => {
-      const lines = createWrappedLines('abcde');
-      assert.notDeepEqual(reflowLargerGetLinesToRemove(lines, 1, 5, 10, nullCell, false), []);
-    });
-  });
 });

src/common/buffer/Constants.ts

@@ -24,7 +24,7 @@ export const NULL_CELL_CODE = 0;
 /**
  * Whitespace cell.
  * This is meant as a replacement for empty cells when needed
- * during rendering lines to preserve correct alignment.
+ * during rendering lines to preserve correct aligment.
  */
 export const WHITESPACE_CELL_CHAR = ' ';
 export const WHITESPACE_CELL_WIDTH = 1;
@@ -36,18 +36,18 @@ export const WHITESPACE_CELL_CODE = 32;
 export const enum Content {
   /**
    * bit 1..21    codepoint, max allowed in UTF32 is 0x10FFFF (21 bits taken)
-   *              read:   `codepoint = content & Content.CODEPOINT_MASK;`
-   *              write:  `content |= codepoint & Content.CODEPOINT_MASK;`
+   *              read:   `codepoint = content & Content.codepointMask;`
+   *              write:  `content |= codepoint & Content.codepointMask;`
    *                      shortcut if precondition `codepoint <= 0x10FFFF` is met:
    *                      `content |= codepoint;`
    */
   CODEPOINT_MASK = 0x1FFFFF,
 
   /**
-   * bit 22       flag indicating whether a cell contains combined content
-   *              read:   `isCombined = content & Content.IS_COMBINED_MASK;`
-   *              set:    `content |= Content.IS_COMBINED_MASK;`
-   *              clear:  `content &= ~Content.IS_COMBINED_MASK;`
+   * bit 22       flag indication whether a cell contains combined content
+   *              read:   `isCombined = content & Content.isCombined;`
+   *              set:    `content |= Content.isCombined;`
+   *              clear:  `content &= ~Content.isCombined;`
    */
   IS_COMBINED_MASK = 0x200000,  // 1 << 21
 
@@ -55,19 +55,19 @@ export const enum Content {
    * bit 1..22    mask to check whether a cell contains any string data
    *              we need to check for codepoint and isCombined bits to see
    *              whether a cell contains anything
-   *              read:   `isEmpty = !(content & Content.HAS_CONTENT_MASK)`
+   *              read:   `isEmpty = !(content & Content.hasContent)`
    */
   HAS_CONTENT_MASK = 0x3FFFFF,
 
   /**
    * bit 23..24   wcwidth value of cell, takes 2 bits (ranges from 0..2)
-   *              read:   `width = (content & Content.WIDTH_MASK) >> Content.WIDTH_SHIFT;`
-   *                      `hasWidth = content & Content.WIDTH_MASK;`
+   *              read:   `width = (content & Content.widthMask) >> Content.widthShift;`
+   *                      `hasWidth = content & Content.widthMask;`
    *                      as long as wcwidth is highest value in `content`:
-   *                      `width = content >> Content.WIDTH_SHIFT;`
-   *              write:  `content |= (width << Content.WIDTH_SHIFT) & Content.WIDTH_MASK;`
+   *                      `width = content >> Content.widthShift;`
+   *              write:  `content |= (width << Content.widthShift) & Content.widthMask;`
    *                      shortcut if precondition `0 <= width <= 3` is met:
-   *                      `content |= width << Content.WIDTH_SHIFT;`
+   *                      `content |= width << Content.widthShift;`
    */
   WIDTH_MASK = 0xC00000,   // 3 << 22
   WIDTH_SHIFT = 22

src/common/buffer/Marker.ts

@@ -30,7 +30,7 @@ export class Marker implements IMarker {
     }
     this.isDisposed = true;
     this.line = -1;
-    // Emit before super.dispose such that dispose listeners get a chance to react
+    // Emit before super.dispose such that dispose listeners get a change to react
     this._onDispose.fire();
     dispose(this._disposables);
     this._disposables.length = 0;

src/common/input/Keyboard.ts

@@ -46,7 +46,7 @@ export function evaluateKeyboardEvent(
     // Whether to cancel event propagation (NOTE: this may not be needed since the event is
     // canceled at the end of keyDown
     cancel: false,
-    // The new key event to emit
+    // The new key even to emit
     key: undefined
   };
   const modifiers = (ev.shiftKey ? 1 : 0) | (ev.altKey ? 2 : 0) | (ev.ctrlKey ? 4 : 0) | (ev.metaKey ? 8 : 0);

src/common/input/TextDecoder.test.ts

@@ -79,7 +79,7 @@ function assertDecodedRange(
   }
   const target = new Uint32Array(count);
   const length = decode(input, target);
-  assert.strictEqual(length, count);
+  assert.equal(length, count);
   let mismatchIndex = -1;
   let index = 0;
   for (let i = min; i < max; ++i) {
@@ -92,8 +92,8 @@ function assertDecodedRange(
     }
     index++;
   }
-  assert.strictEqual(mismatchIndex, -1);
-  assert.strictEqual(outputToString(target, length), input);
+  assert.equal(mismatchIndex, -1);
+  assert.equal(outputToString(target, length), input);
 }
 
 const BATCH_SIZE = 8192;
@@ -116,9 +116,9 @@ describe('text encodings', () => {
     const data = new Uint32Array(s.length);
     for (let i = 0; i < s.length; ++i) {
       data[i] = s.charCodeAt(i);
-      assert.strictEqual(stringFromCodePoint(data[i]), s[i]);
+      assert.equal(stringFromCodePoint(data[i]), s[i]);
     }
-    assert.strictEqual(utf32ToString(data), s);
+    assert.equal(utf32ToString(data), s);
   });
 
   describe('StringToUtf32 decoder', () => {
@@ -159,7 +159,7 @@ describe('text encodings', () => {
         const decoder = new StringToUtf32();
         const target = new Uint32Array(5);
         const length = decoder.decode(String.fromCharCode(0xFEFF), target);
-        assert.strictEqual(length, 0);
+        assert.equal(length, 0);
         decoder.clear();
       });
     });
@@ -169,7 +169,7 @@ describe('text encodings', () => {
       const target = new Uint32Array(500);
       for (let i = 0; i < TEST_STRINGS.length; ++i) {
         const length = decoder.decode(TEST_STRINGS[i], target);
-        assert.strictEqual(toString(target, length), TEST_STRINGS[i]);
+        assert.equal(toString(target, length), TEST_STRINGS[i]);
         decoder.clear();
       }
     });
@@ -184,7 +184,7 @@ describe('text encodings', () => {
           const written = decoder.decode(input[i], target);
           decoded += toString(target, written);
         }
-        assert.strictEqual(decoded, 'Ä€𝄞Ö𝄞€Ü𝄞€');
+        assert(decoded, 'Ä€𝄞Ö𝄞€Ü𝄞€');
       });
     });
   });
@@ -226,7 +226,7 @@ describe('text encodings', () => {
         const target = new Uint32Array(5);
         const utf8Data = stringToUtf8Bytes(String.fromCharCode(0xFEFF));
         const length = decoder.decode(utf8Data, target);
-        assert.strictEqual(length, 0);
+        assert.equal(length, 0);
         decoder.clear();
       });
     });
@@ -237,7 +237,7 @@ describe('text encodings', () => {
       for (let i = 0; i < TEST_STRINGS.length; ++i) {
         const utf8Data = stringToUtf8Bytes(TEST_STRINGS[i]);
         const length = decoder.decode(utf8Data, target);
-        assert.strictEqual(toString(target, length), TEST_STRINGS[i]);
+        assert.equal(toString(target, length), TEST_STRINGS[i]);
         decoder.clear();
       }
     });
@@ -252,7 +252,7 @@ describe('text encodings', () => {
           const written = decoder.decode(utf8Data.slice(i, i + 1), target);
           decoded += toString(target, written);
         }
-        assert.strictEqual(decoded, 'ÄÖÜßöäü');
+        assert(decoded, 'ÄÖÜßöäü');
       });
 
       it('2/3 byte sequences - advance by 1', () => {
@@ -264,7 +264,7 @@ describe('text encodings', () => {
           const written = decoder.decode(utf8Data.slice(i, i + 1), target);
           decoded += toString(target, written);
         }
-        assert.strictEqual(decoded, 'Āր܀߀ö€ä€ü');
+        assert(decoded, 'Āր܀߀ö€ä€ü');
       });
 
       it('2/3/4 byte sequences - advance by 1', () => {
@@ -276,7 +276,7 @@ describe('text encodings', () => {
           const written = decoder.decode(utf8Data.slice(i, i + 1), target);
           decoded += toString(target, written);
         }
-        assert.strictEqual(decoded, 'Ä€𝄞Ö𝄞€Ü𝄞€');
+        assert(decoded, 'Ä€𝄞Ö𝄞€Ü𝄞€');
       });
 
       it('2/3/4 byte sequences - advance by 2', () => {
@@ -288,7 +288,7 @@ describe('text encodings', () => {
           const written = decoder.decode(utf8Data.slice(i, i + 2), target);
           decoded += toString(target, written);
         }
-        assert.strictEqual(decoded, 'Ä€𝄞Ö𝄞€Ü𝄞€');
+        assert(decoded, 'Ä€𝄞Ö𝄞€Ü𝄞€');
       });
 
       it('2/3/4 byte sequences - advance by 3', () => {
@@ -300,7 +300,7 @@ describe('text encodings', () => {
           const written = decoder.decode(utf8Data.slice(i, i + 3), target);
           decoded += toString(target, written);
         }
-        assert.strictEqual(decoded, 'Ä€𝄞Ö𝄞€Ü𝄞€');
+        assert(decoded, 'Ä€𝄞Ö𝄞€Ü𝄞€');
       });
 
       it('BOMs (3 byte sequences) - advance by 2', () => {
@@ -312,7 +312,7 @@ describe('text encodings', () => {
           const written = decoder.decode(utf8Data.slice(i, i + 2), target);
           decoded += toString(target, written);
         }
-        assert.strictEqual(decoded, '');
+        assert.equal(decoded, '');
       });
 
       it('test break after 3 bytes - issue #2495', () => {
@@ -320,37 +320,11 @@ describe('text encodings', () => {
         const target = new Uint32Array(5);
         const utf8Data = fromByteString('\xf0\xa0\x9c\x8e');
         let written = decoder.decode(utf8Data.slice(0, 3), target);
-        assert.strictEqual(written, 0);
+        assert.equal(written, 0);
         written = decoder.decode(utf8Data.slice(3), target);
-        assert.strictEqual(written, 1);
-        assert.strictEqual(toString(target, written), '𠜎');
+        assert.equal(written, 1);
+        assert(toString(target, written), '𠜎');
       });
-
-      describe('0x80 not swallowed in continuation', () => {
-        it('A—B', () => {
-          const decoder = new Utf8ToUtf32();
-          const target = new Uint32Array(5);
-          const utf8Data = new TextEncoder().encode('A—BA—BA—BA—BA—B');
-          let decoded = '';
-          for (let i = 0; i < utf8Data.length; i += 2) {
-            const written = decoder.decode(utf8Data.slice(i, i + 2), target);
-            decoded += toString(target, written);
-          }
-          assert.strictEqual(decoded, 'A—BA—BA—BA—BA—B');
-        });
-        it('A𐀀B', () => {
-          const decoder = new Utf8ToUtf32();
-          const target = new Uint32Array(5);
-          const utf8Data = new TextEncoder().encode('A𐀀BA𐀀BA𐀀BA𐀀BA𐀀B');
-          let decoded = '';
-          for (let i = 0; i < utf8Data.length; i += 2) {
-            const written = decoder.decode(utf8Data.slice(i, i + 2), target);
-            decoded += toString(target, written);
-          }
-          assert.strictEqual(decoded, 'A𐀀BA𐀀BA𐀀BA𐀀BA𐀀B');
-        });
-      });
-
     });
   });
 });

src/common/input/TextDecoder.ts

@@ -158,9 +158,9 @@ export class Utf8ToUtf32 {
       cp &= ((((cp & 0xE0) === 0xC0)) ? 0x1F : (((cp & 0xF0) === 0xE0)) ? 0x0F : 0x07);
       let pos = 0;
       let tmp: number;
-      while ((tmp = this.interim[++pos]) && pos < 4) {
+      while ((tmp = this.interim[++pos] & 0x3F) && pos < 4) {
         cp <<= 6;
-        cp |= tmp & 0x3F;
+        cp |= tmp;
       }
       // missing bytes - read ahead from input
       const type = (((this.interim[0] & 0xE0) === 0xC0)) ? 2 : (((this.interim[0] & 0xF0) === 0xE0)) ? 3 : 4;

src/common/input/WriteBuffer.ts

@@ -267,7 +267,7 @@ export class WriteBuffer extends Disposable {
          * this condition here, also the renderer has no way to spot nonsense updates either.
          * FIXME: A proper fix for this would track the FPS at the renderer entry level separately.
          *
-         * If favoring of FPS shows bad throughput impact, use the following instead. It favors
+         * If favoring of FPS shows bad throughtput impact, use the following instead. It favors
          * throughput by eval'ing `startTime` upfront pulling at least one more chunk into the
          * current microtask queue (executed before setTimeout).
          */

src/common/parser/ApcParser.test.ts

@@ -21,7 +21,7 @@ function identifier(id: IFunctionIdentifier): number {
       throw new Error('only one byte as prefix supported');
     }
     res = id.prefix.charCodeAt(0);
-    if (res < 0x3c || res > 0x3f) {
+    if (res && 0x3c > res || res > 0x3f) {
       throw new Error('prefix must be in range 0x3c .. 0x3f');
     }
   }
@@ -459,29 +459,4 @@ describe('ApcParser - async tests', () => {
       });
     });
   });
-  describe('reset', () => {
-    it('should abort active handlers with end(false) when reset during payload', () => {
-      const ident = identifier({ intermediates: '+', final: 'p' });
-      parser.registerHandler(ident, new TestHandler(reports, 'th'));
-      parser.start(ident);
-      let data = toUtf32('partial');
-      parser.put(data, 0, data.length);
-      parser.reset();
-      assert.deepEqual(reports, [
-        ['th', 'START'],
-        ['th', 'PUT', 'partial'],
-        ['th', 'END', false]
-      ]);
-      reports.length = 0;
-      parser.start(ident);
-      data = toUtf32('complete');
-      parser.put(data, 0, data.length);
-      parser.end(true);
-      assert.deepEqual(reports, [
-        ['th', 'START'],
-        ['th', 'PUT', 'complete'],
-        ['th', 'END', true]
-      ]);
-    });
-  });
 });

src/common/parser/DcsParser.test.ts

@@ -22,7 +22,7 @@ function identifier(id: IFunctionIdentifier): number {
       throw new Error('only one byte as prefix supported');
     }
     res = id.prefix.charCodeAt(0);
-    if (res < 0x3c || res > 0x3f) {
+    if (res && 0x3c > res || res > 0x3f) {
       throw new Error('prefix must be in range 0x3c .. 0x3f');
     }
   }
@@ -470,30 +470,4 @@ describe('DcsParser - async tests', () => {
       });
     });
   });
-  describe('reset', () => {
-    it('should abort active handlers with unhook(false) when reset during payload', () => {
-      const ident = identifier({ intermediates: '+', final: 'p' });
-      const params = Params.fromArray([1, 2, 3]);
-      parser.registerHandler(ident, new TestHandler(reports, 'th'));
-      parser.hook(ident, params);
-      let data = toUtf32('partial');
-      parser.put(data, 0, data.length);
-      parser.reset();
-      assert.deepEqual(reports, [
-        ['th', 'HOOK', [1, 2, 3]],
-        ['th', 'PUT', 'partial'],
-        ['th', 'UNHOOK', false]
-      ]);
-      reports.length = 0;
-      parser.hook(ident, params);
-      data = toUtf32('complete');
-      parser.put(data, 0, data.length);
-      parser.unhook(true);
-      assert.deepEqual(reports, [
-        ['th', 'HOOK', [1, 2, 3]],
-        ['th', 'PUT', 'complete'],
-        ['th', 'UNHOOK', true]
-      ]);
-    });
-  });
 });

src/common/parser/EscapeSequenceParser.test.ts

@@ -243,7 +243,7 @@ describe('EscapeSequenceParser', () => {
       p = new TestEscapeSequenceParser(tansitions);
       assert.deepEqual(p.transitions, tansitions);
     });
-    it('initial states', () => {
+    it('inital states', () => {
       assert.equal(parser.initialState, ParserState.GROUND);
       assert.equal(parser.currentState, ParserState.GROUND);
       assert.equal(parser.osc, '');
@@ -2177,38 +2177,6 @@ describe('EscapeSequenceParser - async', () => {
       parser.reset();
       await parseP(parser, INPUT); // does not throw anymore
     });
-    it('reset during async pause continues at next codepoint in chunk', async () => {
-      const localParser = new TestEscapeSequenceParser();
-      const localStack: any[] = [];
-      localParser.setPrintHandler((data, start, end) => {
-        let result = '';
-        for (let i = start; i < end; ++i) {
-          result += stringFromCodePoint(data[i]);
-        }
-        localStack.push(['PRINT', result]);
-      });
-      localParser.registerCsiHandler({ final: 'm' }, async params => {
-        localStack.push(['SGR', params.toArray()]);
-        return new Promise<boolean>(resolve => setTimeout(() => resolve(true), 0));
-      });
-      const data = '\x1b[1mXY';
-      const container = new Uint32Array(data.length);
-      const decoder = new StringToUtf32();
-      const len = decoder.decode(data, container);
-
-      assert.ok(localParser.parse(container, len) instanceof Promise);
-      localParser.reset();
-      assert.equal(localParser.parseStack.state, ParserStackType.RESET);
-
-      let prev: boolean | undefined = true;
-      let result: void | Promise<boolean> | undefined;
-      while (result = localParser.parse(container, len, prev)) {
-        prev = await result;
-      }
-
-      assert.deepEqual(localStack, [['SGR', [1]], ['PRINT', 'XY']]);
-      assert.equal(localParser.parseStack.state, ParserStackType.NONE);
-    });
     it('correct result on awaited parse call', async () => {
       await parseP(parser, INPUT);
       assert.deepEqual(callstack, RESULT);

src/common/parser/EscapeSequenceParser.ts

@@ -18,7 +18,7 @@ import { ApcParser } from './ApcParser';
 // @vt: #Y   ESC   CSI   "Control Sequence Introducer"   "ESC ["   "Start of a CSI sequence."
 // @vt: #Y   ESC   OSC   "Operating System Command"      "ESC ]"   "Start of an OSC sequence."
 // @vt: #Y   ESC   DCS   "Device Control String"         "ESC P"   "Start of a DCS sequence."
-// @vt: #Y   ESC   ST    "String Terminator"             "ESC \\"  "Terminator used for string type sequences."
+// @vt: #Y   ESC   ST    "String Terminator"             "ESC \"   "Terminator used for string type sequences."
 // @vt: #Y   ESC   PM    "Privacy Message"               "ESC ^"   "Start of a privacy message."
 // @vt: #Y   ESC   APC   "Application Program Command"   "ESC _"   "Start of an APC sequence."
 // @vt: #Y   C1    CSI   "Control Sequence Introducer"   "\x9B"    "Start of a CSI sequence."
@@ -243,7 +243,7 @@ export const VT500_TRANSITION_TABLE = (function (): TransitionTable {
  *
  * This parser is currently hardcoded to operate in ZDM (Zero Default Mode)
  * as suggested by the original parser, thus empty parameters are set to 0.
- * This is not in line with the latest ECMA-48 specification
+ * This this is not in line with the latest ECMA-48 specification
  * (ZDM was part of the early specs and got completely removed later on).
  *
  * Other than the original parser from vt100.net this parser supports
@@ -342,7 +342,7 @@ export class EscapeSequenceParser extends Disposable implements IEscapeSequenceP
         throw new Error('only one byte as prefix supported');
       }
       res = id.prefix.charCodeAt(0);
-      if (res < 0x3c || res > 0x3f) {
+      if (res && 0x3c > res || res > 0x3f) {
         throw new Error('prefix must be in range 0x3c .. 0x3f');
       }
     }

src/common/parser/OscParser.test.ts

@@ -464,28 +464,4 @@ describe('OscParser - async tests', () => {
       });
     });
   });
-  describe('reset', () => {
-    it('should abort active handlers with end(false) when reset during payload', () => {
-      parser.registerHandler(1234, new TestHandler(1234, reports, 'th'));
-      parser.start();
-      let data = toUtf32('1234;partial');
-      parser.put(data, 0, data.length);
-      parser.reset();
-      assert.deepEqual(reports, [
-        ['th', 1234, 'START'],
-        ['th', 1234, 'PUT', 'partial'],
-        ['th', 1234, 'END', false]
-      ]);
-      reports.length = 0;
-      parser.start();
-      data = toUtf32('1234;complete');
-      parser.put(data, 0, data.length);
-      parser.end(true);
-      assert.deepEqual(reports, [
-        ['th', 1234, 'START'],
-        ['th', 1234, 'PUT', 'complete'],
-        ['th', 1234, 'END', true]
-      ]);
-    });
-  });
 });

src/common/parser/Params.test.ts

@@ -199,13 +199,13 @@ describe('Params', () => {
     it('reject params lesser -1', () => {
       const params = new Params();
       params.addParam(-1);
-      assert.throws(() => params.addParam(-2), 'values less than -1 are not allowed');
+      assert.throws(() => params.addParam(-2), 'values lesser than -1 are not allowed');
     });
     it('reject subparams lesser -1', () => {
       const params = new Params();
       params.addParam(-1);
       params.addSubParam(-1);
-      assert.throws(() => params.addSubParam(-2), 'values less than -1 are not allowed');
+      assert.throws(() => params.addSubParam(-2), 'values lesser than -1 are not allowed');
       assert.deepEqual(params.toArray(), [-1, [-1]]);
     });
     it('clamp parsed params', () => {

src/common/parser/Params.ts

@@ -162,7 +162,7 @@ export class Params implements IParams {
       return;
     }
     if (value < -1) {
-      throw new Error('values less than -1 are not allowed');
+      throw new Error('values lesser than -1 are not allowed');
     }
     this._subParamsIdx[this.length] = this._subParamsLength << 8 | this._subParamsLength;
     this.params[this.length++] = value > Constants.MAX_VALUE ? Constants.MAX_VALUE : value;
@@ -172,7 +172,7 @@ export class Params implements IParams {
    * Add a sub parameter value.
    * The sub parameter is automatically associated with the last parameter value.
    * Thus it is not possible to add a subparameter without any parameter added yet.
-   * `Params` only stores up to `maxSubParamsLength` sub parameters, any later
+   * `Params` only stores up to `subParamsLength` sub parameters, any later
    * sub parameter will be ignored.
    */
   public addSubParam(value: number): void {
@@ -185,7 +185,7 @@ export class Params implements IParams {
       return;
     }
     if (value < -1) {
-      throw new Error('values less than -1 are not allowed');
+      throw new Error('values lesser than -1 are not allowed');
     }
     this._subParams[this._subParamsLength++] = value > Constants.MAX_VALUE ? Constants.MAX_VALUE : value;
     this._subParamsIdx[this.length - 1]++;

src/common/parser/Types.ts

@@ -234,8 +234,8 @@ export interface IApcParser extends ISubParser<IApcHandler, ApcFallbackHandlerTy
 
 /**
  * Interface to denote a specific ESC, CSI or DCS handler slot.
- * The values are used to create an integer representation during handler
- * registration before passed to the subparsers as `ident`.
+ * The values are used to create an integer respresentation during handler
+ * regristation before passed to the subparsers as `ident`.
  * The integer translation is made to allow a faster handler access
  * in `EscapeSequenceParser.parse`.
  */

src/common/services/BufferService.test.ts

@@ -1,137 +0,0 @@
-/**
- * Copyright (c) 2026 The xterm.js authors. All rights reserved.
- * @license MIT
- */
-
-import { assert } from 'chai';
-import { AttributeData } from '../buffer/AttributeData';
-import { BufferService } from './BufferService';
-import { OptionsService } from './OptionsService';
-import { MockLogService } from '../TestUtils.test';
-
-describe('BufferService', () => {
-  describe('scroll', () => {
-    const eraseAttr = new AttributeData();
-
-    it('should decrement ydisp when the buffer is full and the user has scrolled up', () => {
-      const optionsService = new OptionsService({ rows: 3, cols: 10, scrollback: 2 });
-      const bufferService = new BufferService(optionsService, new MockLogService());
-      const buffer = bufferService.buffer;
-
-      while (!buffer.lines.isFull) {
-        bufferService.scroll(eraseAttr);
-      }
-      assert.strictEqual(buffer.lines.length, 5);
-
-      bufferService.isUserScrolling = true;
-      buffer.ydisp = 2;
-      const ybaseBefore = buffer.ybase;
-
-      bufferService.scroll(eraseAttr);
-
-      assert.strictEqual(buffer.ybase, ybaseBefore);
-      assert.strictEqual(buffer.ydisp, 1);
-    });
-
-    it('should not advance ydisp with ybase while the user has scrolled up and the buffer is not full', () => {
-      const optionsService = new OptionsService({ rows: 3, cols: 10, scrollback: 2 });
-      const bufferService = new BufferService(optionsService, new MockLogService());
-      const buffer = bufferService.buffer;
-
-      bufferService.isUserScrolling = true;
-      buffer.ydisp = 0;
-      const ybaseBefore = buffer.ybase;
-
-      bufferService.scroll(eraseAttr);
-
-      assert.strictEqual(buffer.ybase, ybaseBefore + 1);
-      assert.strictEqual(buffer.ydisp, 0);
-    });
-
-    it('should follow ybase with ydisp when the user is not scrolling', () => {
-      const optionsService = new OptionsService({ rows: 3, cols: 10, scrollback: 2 });
-      const bufferService = new BufferService(optionsService, new MockLogService());
-      const buffer = bufferService.buffer;
-
-      while (!buffer.lines.isFull) {
-        bufferService.scroll(eraseAttr);
-      }
-
-      bufferService.isUserScrolling = false;
-      bufferService.scroll(eraseAttr);
-
-      assert.strictEqual(buffer.ydisp, buffer.ybase);
-    });
-
-    it('should scroll within DECSTBM margins without affecting lines outside the region', () => {
-      const optionsService = new OptionsService({ rows: 5, cols: 10, scrollback: 10 });
-      const bufferService = new BufferService(optionsService, new MockLogService());
-      const buffer = bufferService.buffer;
-
-      const markRow = (row: number, ch: string) => {
-        buffer.lines.get(buffer.ybase + row)!.setCellFromCodepoint(0, ch.charCodeAt(0), 1, eraseAttr);
-      };
-      markRow(0, 'A');
-      markRow(1, 'B');
-      markRow(2, 'C');
-      markRow(3, 'D');
-      markRow(4, 'E');
-      buffer.scrollTop = 1;
-      buffer.scrollBottom = 3;
-
-      bufferService.scroll(eraseAttr);
-
-      assert.strictEqual(buffer.lines.get(buffer.ybase + 0)!.translateToString().trim(), 'A');
-      assert.strictEqual(buffer.lines.get(buffer.ybase + 1)!.translateToString().trim(), 'C');
-      assert.strictEqual(buffer.lines.get(buffer.ybase + 2)!.translateToString().trim(), 'D');
-      assert.strictEqual(buffer.lines.get(buffer.ybase + 3)!.translateToString(true).trim(), '');
-      assert.strictEqual(buffer.lines.get(buffer.ybase + 4)!.translateToString().trim(), 'E');
-    });
-  });
-
-  describe('scrollLines', () => {
-    it('should move ydisp and set isUserScrolling when scrolling up', () => {
-      const optionsService = new OptionsService({ rows: 10, cols: 80, scrollback: 10 });
-      const bufferService = new BufferService(optionsService, new MockLogService());
-      const buffer = bufferService.buffer;
-      buffer.ybase = 5;
-      buffer.ydisp = 5;
-
-      let scrollEvent: number | undefined;
-      bufferService.onScroll(e => { scrollEvent = e; });
-
-      bufferService.scrollLines(-2);
-
-      assert.strictEqual(buffer.ydisp, 3);
-      assert.strictEqual(bufferService.isUserScrolling, true);
-      assert.strictEqual(scrollEvent, 3);
-    });
-
-    it('should not scroll above the top of the buffer', () => {
-      const optionsService = new OptionsService({ rows: 10, cols: 80, scrollback: 10 });
-      const bufferService = new BufferService(optionsService, new MockLogService());
-      const buffer = bufferService.buffer;
-      buffer.ybase = 5;
-      buffer.ydisp = 0;
-
-      bufferService.scrollLines(-1);
-
-      assert.strictEqual(buffer.ydisp, 0);
-      assert.strictEqual(bufferService.isUserScrolling, false);
-    });
-
-    it('should clear isUserScrolling when scrolling to the bottom', () => {
-      const optionsService = new OptionsService({ rows: 10, cols: 80, scrollback: 10 });
-      const bufferService = new BufferService(optionsService, new MockLogService());
-      const buffer = bufferService.buffer;
-      buffer.ybase = 5;
-      buffer.ydisp = 2;
-      bufferService.isUserScrolling = true;
-
-      bufferService.scrollLines(10);
-
-      assert.strictEqual(buffer.ydisp, 5);
-      assert.strictEqual(bufferService.isUserScrolling, false);
-    });
-  });
-});

src/common/services/CharsetService.test.ts

@@ -1,43 +0,0 @@
-/**
- * Copyright (c) 2026 The xterm.js authors. All rights reserved.
- * @license MIT
- */
-
-import { assert } from 'chai';
-import { CHARSETS } from '../data/Charsets';
-import { CharsetService } from './CharsetService';
-
-describe('CharsetService', () => {
-  let service: CharsetService;
-
-  beforeEach(() => {
-    service = new CharsetService();
-  });
-
-  it('should not update active charset when designating an inactive glevel', () => {
-    service.setgCharset(1, CHARSETS['0']);
-    assert.strictEqual(service.glevel, 0);
-    assert.ok(service.charset === undefined);
-  });
-
-  it('should expose the designated charset after setgLevel', () => {
-    service.setgCharset(1, CHARSETS['0']);
-    service.setgLevel(1);
-    assert.strictEqual(service.charset, CHARSETS['0']);
-  });
-
-  it('should update active charset when designating the current glevel', () => {
-    service.setgLevel(1);
-    service.setgCharset(1, CHARSETS['0']);
-    assert.strictEqual(service.charset, CHARSETS['0']);
-  });
-
-  it('should reset glevel, charsets, and active charset', () => {
-    service.setgCharset(1, CHARSETS['0']);
-    service.setgLevel(1);
-    service.reset();
-    assert.strictEqual(service.glevel, 0);
-    assert.deepEqual(service.charsets, []);
-    assert.ok(service.charset === undefined);
-  });
-});

src/common/services/Services.ts

@@ -344,13 +344,13 @@ export type UnicodeCharWidth = 0 | 1 | 2;
 export const IUnicodeService = createDecorator<IUnicodeService>('UnicodeService');
 export interface IUnicodeService {
   serviceBrand: undefined;
-  /** Register a Unicode version provider. */
+  /** Register an Unicode version provider. */
   register(provider: IUnicodeVersionProvider): void;
   /** Registered Unicode versions. */
   readonly versions: string[];
   /** Currently active version. */
   activeVersion: string;
-  /** Event triggered when the active version changes. */
+  /** Event triggered, when activate version changed. */
   readonly onChange: IEvent<string>;
 
   /**

src/headless/Terminal.ts

@@ -99,6 +99,10 @@ export class Terminal extends CoreTerminal {
    * Clear the entire buffer, making the prompt line the new first line.
    */
   public clear(): void {
+    if (this.buffer.ybase === 0 && this.buffer.y === 0) {
+      // Don't clear if it's already clear
+      return;
+    }
     this.buffer.clearAllMarkers();
     this.buffer.lines.set(0, this.buffer.lines.get(this.buffer.ybase + this.buffer.y)!);
     this.buffer.lines.length = 1;

test/benchmark/BufferLine.benchmark.ts

@@ -1,113 +0,0 @@
-/**
- * Copyright (c) 2026 The xterm.js authors. All rights reserved.
- * @license MIT
- */
-
-import { perfContext, before, RuntimeCase } from 'xterm-benchmark';
-import { BufferLine, DEFAULT_ATTR_DATA } from 'common/buffer/BufferLine';
-import { BufferLineStringCache } from 'common/buffer/BufferLineStringCache';
-import { CellData } from 'common/buffer/CellData';
-import { BgFlags, NULL_CELL_CHAR, NULL_CELL_WIDTH, NULL_CELL_CODE, UnderlineStyle } from 'common/buffer/Constants';
-
-const ITERATIONS = 500_000;
-const stringCache = new BufferLineStringCache();
-const nullCell = CellData.fromCharData([0, NULL_CELL_CHAR, NULL_CELL_WIDTH, NULL_CELL_CODE]);
-const yCell = CellData.fromCharData([0, 'y', 1, 'y'.charCodeAt(0)]);
-
-function fillPlainY(line: BufferLine, cols: number): void {
-  for (let i = 0; i < cols; i++) {
-    line.setCellFromCodepoint(i, 'y'.charCodeAt(0), 1, DEFAULT_ATTR_DATA);
-  }
-}
-
-function setupScrollRecyclePair(cols: number): { recycled: BufferLine, blank: BufferLine } {
-  const blank = new BufferLine(stringCache, cols, nullCell, false);
-  const recycled = new BufferLine(stringCache, cols, yCell, false);
-  fillPlainY(recycled, cols);
-  return { recycled, blank };
-}
-
-/** Source line with combining chars and extended attrs spread across columns. */
-function buildSparseSourceLine(cols: number): BufferLine {
-  const line = new BufferLine(stringCache, cols, nullCell, false);
-  for (let i = 0; i < cols; i++) {
-    if (i % 10 === 0) {
-      const cell = CellData.fromCharData([0, 'a', 1, 'a'.charCodeAt(0)]);
-      cell.extended.underlineStyle = UnderlineStyle.CURLY;
-      cell.bg |= BgFlags.HAS_EXTENDED;
-      line.setCell(i, cell);
-    } else if (i % 17 === 0) {
-      line.setCell(i, CellData.fromCharData([1, 'e\u0301', 1, '\u0301'.charCodeAt(0)]));
-    } else {
-      line.setCellFromCodepoint(i, 'y'.charCodeAt(0), 1, DEFAULT_ATTR_DATA);
-    }
-  }
-  return line;
-}
-
-function setupCopyFromSparsePair(cols: number): { dest: BufferLine, src: BufferLine } {
-  const src = buildSparseSourceLine(cols);
-  const dest = new BufferLine(stringCache, cols, yCell, false);
-  fillPlainY(dest, cols);
-  return { dest, src };
-}
-
-perfContext('BufferLine.copyFrom (scroll recycle)', () => {
-  perfContext('cols=80', () => {
-    let recycled: BufferLine;
-    let blank: BufferLine;
-    before(() => {
-      ({ recycled, blank } = setupScrollRecyclePair(80));
-    });
-    new RuntimeCase('', () => {
-      for (let i = 0; i < ITERATIONS; i++) {
-        recycled.copyFrom(blank);
-      }
-      return { payloadSize: ITERATIONS };
-    }, { fork: false }).showAverageRuntime();
-  });
-
-  perfContext('cols=279', () => {
-    let recycled: BufferLine;
-    let blank: BufferLine;
-    before(() => {
-      ({ recycled, blank } = setupScrollRecyclePair(279));
-    });
-    new RuntimeCase('', () => {
-      for (let i = 0; i < ITERATIONS; i++) {
-        recycled.copyFrom(blank);
-      }
-      return { payloadSize: ITERATIONS };
-    }, { fork: false }).showAverageRuntime();
-  });
-});
-
-perfContext('BufferLine.copyFrom (sparse source: combined + extended attrs)', () => {
-  perfContext('cols=80', () => {
-    let dest: BufferLine;
-    let src: BufferLine;
-    before(() => {
-      ({ dest, src } = setupCopyFromSparsePair(80));
-    });
-    new RuntimeCase('', () => {
-      for (let i = 0; i < ITERATIONS; i++) {
-        dest.copyFrom(src);
-      }
-      return { payloadSize: ITERATIONS };
-    }, { fork: false }).showAverageRuntime();
-  });
-
-  perfContext('cols=279', () => {
-    let dest: BufferLine;
-    let src: BufferLine;
-    before(() => {
-      ({ dest, src } = setupCopyFromSparsePair(279));
-    });
-    new RuntimeCase('', () => {
-      for (let i = 0; i < ITERATIONS; i++) {
-        dest.copyFrom(src);
-      }
-      return { payloadSize: ITERATIONS };
-    }, { fork: false }).showAverageRuntime();
-  });
-});

test/benchmark/DecorationService.benchmark.ts

@@ -4,8 +4,8 @@
  */
 
 import { perfContext, before, RuntimeCase } from 'xterm-benchmark';
-import { DecorationService } from 'common/services/DecorationService';
-import { MockLogService, MockBufferService, MockOptionsService } from 'common/TestUtils.test';
+import { DecorationService } from '../../src/common/services/DecorationService';
+import { MockLogService, MockBufferService, MockOptionsService } from '../../src/common/TestUtils.test';
 const enum Constants {
   COLS = 80,
   ROWS = 30,

test/benchmark/EscapeSequenceParser.benchmark.ts

@@ -4,12 +4,12 @@
  */
 import { perfContext, before, beforeEach, ThroughputRuntimeCase } from 'xterm-benchmark';
 
-import { EscapeSequenceParser } from 'common/parser/EscapeSequenceParser';
-import { C0, C1 } from 'common/data/EscapeSequences';
-import { IDcsHandler, IOscHandler, IApcHandler, IParams } from 'common/parser/Types';
-import { OscHandler } from 'common/parser/OscParser';
-import { DcsHandler } from 'common/parser/DcsParser';
-import { ApcHandler } from 'common/parser/ApcParser';
+import { EscapeSequenceParser } from '../../src/common/parser/EscapeSequenceParser';
+import { C0, C1 } from '../../src/common/data/EscapeSequences';
+import { IDcsHandler, IOscHandler, IApcHandler, IParams } from '../../src/common/parser/Types';
+import { OscHandler } from '../../src/common/parser/OscParser';
+import { DcsHandler } from '../../src/common/parser/DcsParser';
+import { ApcHandler } from '../../src/common/parser/ApcParser';
 
 const SIZE = 5000000;
 

test/benchmark/Event.benchmark.ts

@@ -4,7 +4,7 @@
  */
 
 import { perfContext, before, RuntimeCase } from 'xterm-benchmark';
-import { Emitter } from 'common/Event';
+import { Emitter } from '../../src/common/Event';
 
 const ITERATIONS = 1_000_000;
 

test/benchmark/Terminal.benchmark.ts

@@ -6,8 +6,8 @@
 import { perfContext, before, ThroughputRuntimeCase } from 'xterm-benchmark';
 
 import { spawn } from 'node-pty';
-import { Utf8ToUtf32, stringFromCodePoint } from 'common/input/TextDecoder';
-import { CoreBrowserTerminal } from 'browser/CoreBrowserTerminal';
+import { Utf8ToUtf32, stringFromCodePoint } from '../../src/common/input/TextDecoder';
+import { CoreBrowserTerminal } from '../../src/browser/CoreBrowserTerminal';
 
 perfContext('Terminal: ls -lR /usr/lib', () => {
   let content = '';

test/benchmark/tsconfig.json

@@ -11,11 +11,7 @@
     "moduleResolution": "nodenext",
     "strict": false,
     "target": "es2021",
-    "module": "nodenext",
-    "paths": {
-      "common/*": ["../../src/common/*"],
-      "browser/*": ["../../src/browser/*"]
-    }
+    "module": "nodenext"
   },
   "include": [
     "./**/*",

test/playwright/SharedRendererTests.ts

@@ -980,7 +980,7 @@ export function injectSharedRendererTests(ctx: ISharedRendererTestContext): void
   });
 
   test.describe('selectionInactiveBackground', async () => {
-    test('should render the inactive selection when not focused', async () => {
+    test('should render the the inactive selection when not focused', async () => {
       const theme: ITheme = {
         selectionBackground: '#FF000080',
         selectionInactiveBackground: '#0000FF80'