webgl stress + glyph-integrity tests for atlas merges; repro vscode#322756 single-terminal garble

2026-06-28 18:27:37 -07:00
parent 8aab310366
commit e3399b1db8
8 changed files with 1121 additions and 0 deletions
@@ -0,0 +1,45 @@
+/**
+ * Copyright (c) 2025 The xterm.js authors. All rights reserved.
+ * @license MIT
+ * EXPERIMENT: try to reproduce vscode#322756 garbled single-terminal render.
+ */
+import test, { expect } from '@playwright/test';
+import { ITestContext, createTestContext, openTerminal } from '../../../test/playwright/TestUtils';
+import { captureRowSignatures, expectSignatureMatches, getAtlasPageCount, loadWebglStrict, setMaxAtlasPages, waitForRender, writeAndWaitForRender } from '../../../test/playwright/RendererTestUtils';
+import { generateColoredAsciiFlood } from '../../../test/playwright/SyntheticTui';
+
+let ctx: ITestContext;
+test.beforeAll(async ({ browser }) => { ctx = await createTestContext(browser); });
+test.afterAll(async () => await ctx.page.close());
+
+test.describe('repro #322756', () => {
+  test.skip(({ browserName }) => browserName !== 'chromium');
+  test.describe.configure({ timeout: 60000 });
+
+  test('header survives merge race with per-chunk sync', async () => {
+    await openTerminal(ctx, { cols: 80, rows: 24 });
+    await loadWebglStrict(ctx);
+    await setMaxAtlasPages(ctx, 4);
+    const cols = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
+    // Alt-buffer TUI: pinned header on row 1, body churns below (like Copilot CLI).
+    await writeAndWaitForRender(ctx, '\x1b[?1049h\x1b[H HEADER_REF_0123456789');
+    const ref = await captureRowSignatures(ctx, 1, cols);
+    let maxDiff = 0;
+    for (let c = 0; c < 30; c++) {
+      // redraw header + churn body rows 2..24 with unique glyphs, header stays put
+      let frame = '\x1b[2;1H';
+      frame += generateColoredAsciiFlood(23 * 78, c * 23 * 78);
+      await writeAndWaitForRender(ctx, frame);
+      const now = await captureRowSignatures(ctx, 1, cols); // forces GPU sync
+      for (let i = 0; i < cols.length; i++) {
+        const d = Math.max(...ref[i].map((v, k) => Math.abs(v - now[i][k])));
+        maxDiff = Math.max(maxDiff, d);
+      }
+    }
+    console.error('[repro] pages=', await getAtlasPageCount(ctx), 'headerMaxDiff=', maxDiff);
+    const after = await captureRowSignatures(ctx, 1, cols);
+    for (let i = 0; i < cols.length; i++) {
+      expectSignatureMatches(after[i], ref[i], 14, `header col ${cols[i]} garbled`);
+    }
+  });
+});