Add brace-style lint rule and fix violations

Enforce 1tbs brace style with allowSingleLine per #5900.
Auto-fix else/catch brace placement across the codebase and
move a comment in font.ts that blocked else-if formatting.

Co-authored-by: Daniel Imms <Tyriar@users.noreply.github.com>

addons/addon-ligatures/src/font.ts

@@ -65,9 +65,8 @@ export default async function load(fontFamily: string, cacheSize: number): Promi
           console.error(err.name, err.message);
         }
       }
-    }
-    // Latest proposal https://bugs.chromium.org/p/chromium/issues/detail?id=1312603
-    else if (typeof window !== 'undefined' && 'queryLocalFonts' in window) {
+    } else if (typeof window !== 'undefined' && 'queryLocalFonts' in window) {
+      // Latest proposal https://bugs.chromium.org/p/chromium/issues/detail?id=1312603
       const fonts: Record<string, IFontMetadata[]> = {};
       try {
         const fontsIterator = await (window as any).queryLocalFonts();

addons/addon-serialize/src/SerializeAddon.ts

@@ -291,21 +291,15 @@ class StringSerializeHandler extends BaseSerializeHandler {
       } else {
         if (fgChanged) {
           const color = cell.getFgColor();
-          if (cell.isFgRGB()) { sgrSeq.push(38, 2, (color >>> 16) & 0xFF, (color >>> 8) & 0xFF, color & 0xFF); }
-          else if (cell.isFgPalette()) {
-            if (color >= 16) { sgrSeq.push(38, 5, color); }
-            else { sgrSeq.push(color & 8 ? 90 + (color & 7) : 30 + (color & 7)); }
-          }
-          else { sgrSeq.push(39); }
+          if (cell.isFgRGB()) { sgrSeq.push(38, 2, (color >>> 16) & 0xFF, (color >>> 8) & 0xFF, color & 0xFF); } else if (cell.isFgPalette()) {
+            if (color >= 16) { sgrSeq.push(38, 5, color); } else { sgrSeq.push(color & 8 ? 90 + (color & 7) : 30 + (color & 7)); }
+          } else { sgrSeq.push(39); }
         }
         if (bgChanged) {
           const color = cell.getBgColor();
-          if (cell.isBgRGB()) { sgrSeq.push(48, 2, (color >>> 16) & 0xFF, (color >>> 8) & 0xFF, color & 0xFF); }
-          else if (cell.isBgPalette()) {
-            if (color >= 16) { sgrSeq.push(48, 5, color); }
-            else { sgrSeq.push(color & 8 ? 100 + (color & 7) : 40 + (color & 7)); }
-          }
-          else { sgrSeq.push(49); }
+          if (cell.isBgRGB()) { sgrSeq.push(48, 2, (color >>> 16) & 0xFF, (color >>> 8) & 0xFF, color & 0xFF); } else if (cell.isBgPalette()) {
+            if (color >= 16) { sgrSeq.push(48, 5, color); } else { sgrSeq.push(color & 8 ? 100 + (color & 7) : 40 + (color & 7)); }
+          } else { sgrSeq.push(49); }
         }
         if (flagsChanged) {
           if (cell.isInverse() !== oldCell.isInverse()) { sgrSeq.push(cell.isInverse() ? 7 : 27); }
@@ -646,8 +640,7 @@ export class HTMLSerializeHandler extends BaseSerializeHandler {
     // For xterm headless: fallback to ansi colors
     if ((_terminal as any)._core._themeService) {
       this._ansiColors = (_terminal as any)._core._themeService.colors.ansi;
-    }
-    else {
+    } else {
       this._ansiColors = DEFAULT_ANSI_COLORS;
     }
   }

demo/client/client.ts

@@ -521,8 +521,7 @@ function initAddons(term: Terminal): void {
           } else if (name === 'webLinks') {
             controlBar.setTabVisible('addon-web-links', true);
           }
-        }
-        catch {
+        } catch {
           addon.instance = undefined;
           checkbox.checked = false;
           checkbox.disabled = true;

eslint.config.mjs

@@ -128,6 +128,7 @@ export default tseslint.config(
       'no-fallthrough': 'off',
       'prefer-spread': 'off',
       'object-curly-spacing': ['warn', 'always'],
+      'brace-style': ['warn', '1tbs', { allowSingleLine: true }],
       'prefer-const': 'warn',
       'spaced-comment': ['warn', 'always', { markers: ['/'], exceptions: ['-'] }]
     }

src/browser/CoreBrowserTerminal.ts

@@ -563,8 +563,7 @@ export class CoreBrowserTerminal extends CoreTerminal implements ITerminal {
 
     try {
       this._onWillOpen.fire(this.element);
-    }
-    catch { /* fails to load addon for some reason */ }
+    } catch { /* fails to load addon for some reason */ }
     if (!this._renderService.hasRenderer()) {
       this._renderService.setRenderer(this._createRenderer());
     }

src/common/Color.ts

@@ -132,8 +132,7 @@ export namespace css {
       $ctx.globalCompositeOperation = 'copy';
       $litmusColor = $ctx.createLinearGradient(0, 0, 1, 1);
     }
-  }
-  catch {
+  } catch {
     // noop
   }
 

src/common/InputHandler.ts

@@ -1268,8 +1268,7 @@ export class InputHandler extends Disposable implements IInputHandler {
           for (; j >= 0; j--) {
             this._bufferService.scroll(this._eraseAttrData());
           }
-        }
-        else {
+        } else {
           j = this._bufferService.rows;
           this._dirtyRowTracker.markDirty(j - 1);
           while (j--) {

src/common/buffer/CellData.ts

@@ -62,8 +62,7 @@ export class CellData extends AttributeData implements ICellData {
     // surrogates and combined strings need special treatment
     if (value[CHAR_DATA_CHAR_INDEX].length > 2) {
       combined = true;
-    }
-    else if (value[CHAR_DATA_CHAR_INDEX].length === 2) {
+    } else if (value[CHAR_DATA_CHAR_INDEX].length === 2) {
       const code = value[CHAR_DATA_CHAR_INDEX].charCodeAt(0);
       // if the 2-char string is a surrogate create single codepoint
       // everything else is combined
@@ -71,16 +70,13 @@ export class CellData extends AttributeData implements ICellData {
         const second = value[CHAR_DATA_CHAR_INDEX].charCodeAt(1);
         if (0xDC00 <= second && second <= 0xDFFF) {
           this.content = ((code - 0xD800) * 0x400 + second - 0xDC00 + 0x10000) | (value[CHAR_DATA_WIDTH_INDEX] << Content.WIDTH_SHIFT);
-        }
-        else {
+        } else {
           combined = true;
         }
-      }
-      else {
+      } else {
         combined = true;
       }
-    }
-    else {
+    } else {
       this.content = value[CHAR_DATA_CHAR_INDEX].charCodeAt(0) | (value[CHAR_DATA_WIDTH_INDEX] << Content.WIDTH_SHIFT);
     }
     if (combined) {

src/common/input/Keyboard.ts

@@ -58,22 +58,19 @@ export function evaluateKeyboardEvent(
         } else {
           result.key = C0.ESC + '[A';
         }
-      }
-      else if (ev.key === 'UIKeyInputLeftArrow') {
+      } else if (ev.key === 'UIKeyInputLeftArrow') {
         if (applicationCursorMode) {
           result.key = C0.ESC + 'OD';
         } else {
           result.key = C0.ESC + '[D';
         }
-      }
-      else if (ev.key === 'UIKeyInputRightArrow') {
+      } else if (ev.key === 'UIKeyInputRightArrow') {
         if (applicationCursorMode) {
           result.key = C0.ESC + 'OC';
         } else {
           result.key = C0.ESC + '[C';
         }
-      }
-      else if (ev.key === 'UIKeyInputDownArrow') {
+      } else if (ev.key === 'UIKeyInputDownArrow') {
         if (applicationCursorMode) {
           result.key = C0.ESC + 'OB';
         } else {

src/common/input/TextDecoder.ts

@@ -230,8 +230,7 @@ export class Utf8ToUtf32 {
         && !((byte1 = input[i]) & 0x80)
         && !((byte2 = input[i + 1]) & 0x80)
         && !((byte3 = input[i + 2]) & 0x80)
-        && !((byte4 = input[i + 3]) & 0x80))
-      {
+        && !((byte4 = input[i + 3]) & 0x80)) {
         target[size++] = byte1;
         target[size++] = byte2;
         target[size++] = byte3;