fix(terminal): alias diagnostics_channel in Electron live bundles

The background-rendering live test bundles the terminal with esbuild,
which does not use the Vite alias. The ligatures addon then fails to
resolve node:diagnostics_channel, and Electron keeps that process alive
until the job timeout. Point the import at the renderer stub and exit
if the bundle fails.

application/i18n/locales/en/core.ts

@@ -614,6 +614,8 @@ Highlight the focused split pane:
   'settings.terminal.font.weightBold.desc': 'Weight for bold text (100-900)',
   'settings.terminal.font.smoothing': 'Font smoothing',
   'settings.terminal.font.smoothing.desc': 'Use native macOS font anti-aliasing',
+  'settings.terminal.font.ligatures': 'Font ligatures',
+  'settings.terminal.font.ligatures.desc': 'Render ligatures such as != when the terminal font includes them',
   'settings.terminal.font.linePadding': 'Line padding',
   'settings.terminal.font.linePadding.desc': 'Additional space between lines (0-10)',
   'settings.terminal.font.emulationType': 'Terminal emulation type',

application/i18n/locales/es/core.ts

@@ -529,6 +529,8 @@ Resalta el panel dividido enfocado:
   'settings.terminal.font.weightBold.desc': 'Peso del texto en negrita (100-900)',
   'settings.terminal.font.smoothing': 'Suavizado de fuente',
   'settings.terminal.font.smoothing.desc': 'Usar el anti-aliasing nativo de fuentes de macOS',
+  'settings.terminal.font.ligatures': 'Ligaduras de fuente',
+  'settings.terminal.font.ligatures.desc': 'Mostrar ligaduras como != cuando la fuente del terminal las incluye',
   'settings.terminal.font.linePadding': 'Espaciado de líneas',
   'settings.terminal.font.linePadding.desc': 'Espacio adicional entre líneas (0-10)',
   'settings.terminal.font.emulationType': 'Tipo de emulación de terminal',

application/i18n/locales/ru/core.ts

@@ -582,6 +582,8 @@ export const ruCoreMessages: Messages = {
   'settings.terminal.font.weightBold.desc': 'Толщина жирного текста (100-900)',
   'settings.terminal.font.smoothing': 'Сглаживание шрифта',
   'settings.terminal.font.smoothing.desc': 'Использовать родное сглаживание шрифтов macOS',
+  'settings.terminal.font.ligatures': 'Лигатуры шрифта',
+  'settings.terminal.font.ligatures.desc': 'Показывать лигатуры вроде !=, если шрифт терминала их содержит',
   'settings.terminal.font.linePadding': 'Межстрочный отступ',
   'settings.terminal.font.linePadding.desc': 'Дополнительное пространство между строками (0-10)',
   'settings.terminal.font.emulationType': 'Тип эмуляции терминала',

application/i18n/locales/zh-CN/terminal.ts

@@ -278,6 +278,8 @@ export const zhCNTerminalMessages: Messages = {
   'settings.terminal.font.weightBold.desc': '粗体文本字重 (100-900)',
   'settings.terminal.font.smoothing': '字体平滑',
   'settings.terminal.font.smoothing.desc': '使用 macOS 原生字体抗锯齿',
+  'settings.terminal.font.ligatures': '字体连字',
+  'settings.terminal.font.ligatures.desc': '支持连字的字体把 != 这类字符显示成一个符号',
   'settings.terminal.font.linePadding': '行间距',
   'settings.terminal.font.linePadding.desc': '行之间的额外间距 (0-10)',
   'settings.terminal.font.emulationType': '终端仿真类型',

application/i18n/locales/zh-TW/terminal.ts

@@ -278,6 +278,8 @@ export const zhTWTerminalMessages: Messages = {
   'settings.terminal.font.weightBold.desc': '粗體文字字重 (100-900)',
   'settings.terminal.font.smoothing': '字型平滑',
   'settings.terminal.font.smoothing.desc': '使用 macOS 原生字型抗鋸齒',
+  'settings.terminal.font.ligatures': '字型連字',
+  'settings.terminal.font.ligatures.desc': '支援連字的字型把 != 這類字元顯示成一個符號',
   'settings.terminal.font.linePadding': '行間距',
   'settings.terminal.font.linePadding.desc': '行之間的額外間距 (0-10)',
   'settings.terminal.font.emulationType': '終端模擬型別',

components/settings/tabs/SettingsTerminalTab.tsx

@@ -602,6 +602,17 @@ function SettingsTerminalTab(props: {
           />
         </SettingRow>
 
+        <SettingRow
+          anchorId="terminal-font-ligatures"
+          label={t("settings.terminal.font.ligatures")}
+          description={t("settings.terminal.font.ligatures.desc")}
+        >
+          <Toggle
+            checked={terminalSettings.fontLigatures}
+            onChange={(v) => updateTerminalSetting("fontLigatures", v)}
+          />
+        </SettingRow>
+
         <SettingRow
           anchorId="terminal-font-line-padding"
           label={t("settings.terminal.font.linePadding")}

components/terminal/runtime/createXTermRuntime.ts

@@ -3,6 +3,7 @@ import { stringCellWidth } from "../autocomplete/terminalStringCellWidth";
 import type { TerminalBroadcastInputOptions } from "../terminalHelpers";
 import { FitAddon } from "@xterm/addon-fit";
 import { ImageAddon } from "@xterm/addon-image";
+import { LigaturesAddon } from "@xterm/addon-ligatures";
 import { SearchAddon } from "@xterm/addon-search";
 import { SerializeAddon } from "@xterm/addon-serialize";
 import { UnicodeGraphemesAddon } from "@xterm/addon-unicode-graphemes";
@@ -99,6 +100,10 @@ import { optionYankLastArgSequence } from "./optionYankLastArg";
 import { watchDevicePixelRatio } from "./rendererDprWatch";
 import { dispatchWin32InputModeEvent } from "./win32InputMode";
 import { shouldDeferWebglUntilVisible } from "./webglRendererPolicy";
+import {
+  createTerminalLigatureController,
+  terminalFontLigaturesEnabled,
+} from "./terminalFontLigatures";
 import { createWebglRendererController } from "./webglRendererController";
 import {
   captureMiddleClickTerminalMouseEvent,
@@ -277,6 +282,11 @@ export type XTermRuntime = {
   ensureWebglRenderer: () => void;
   /** Drop the WebGL addon while keeping the terminal alive (soft-hide). */
   suspendWebglRenderer: () => void;
+  /**
+   * Turn programming ligatures on or off. An active WebGL renderer is rebuilt
+   * because its glyph atlas captures font-feature-settings only at creation.
+   */
+  syncFontLigatures: (enabled: boolean) => void;
   /**
    * True while this terminal holds decoded inline images (Kitty / SIXEL / IIP).
    * Hibernate snapshots are text-only, so a session that reports true must not
@@ -850,6 +860,26 @@ export const createXTermRuntime = (ctx: CreateXTermRuntimeContext): XTermRuntime
   });
   const loadWebglRenderer = webglController.ensure;
   const suspendWebglRenderer = webglController.suspend;
+  const reloadWebglRenderer = () => {
+    if (!webglLoaded) return;
+    suspendWebglRenderer();
+    loadWebglRenderer();
+  };
+  // The ligatures addon sets font-feature-settings on the terminal element.
+  // WebGL's glyph atlas inherits that only when the atlas is created, so this
+  // has to run before the first WebGL load. Later toggles rebuild WebGL.
+  const ligatures = createTerminalLigatureController({
+    createAddon: () => new LigaturesAddon(),
+    loadAddon: (addon) => term.loadAddon(addon),
+    isWebglActive: () => webglLoaded,
+    recreateWebgl: reloadWebglRenderer,
+    repaint: repaintTerminal,
+    warn: (message, error) => {
+      if (error === undefined) logger.warn(message);
+      else logger.warn(message, error);
+    },
+  });
+  ligatures.apply(terminalFontLigaturesEnabled(settings));
 
   if (!performanceConfig.useWebGLAddon) {
     logger.info(
@@ -3325,6 +3355,9 @@ export const createXTermRuntime = (ctx: CreateXTermRuntimeContext): XTermRuntime
     clearTextureAtlas: clearWebglTextureAtlas,
     ensureWebglRenderer: loadWebglRenderer,
     suspendWebglRenderer,
+    syncFontLigatures: (enabled: boolean) => {
+      ligatures.apply(enabled);
+    },
     hasInlineImages,
     resetKittyConnectionInputState: clearKittyConnectionInputState,
     flushKittyKeyboardReleases: clearKittyTransientInputState,
@@ -3344,6 +3377,7 @@ export const createXTermRuntime = (ctx: CreateXTermRuntimeContext): XTermRuntime
       pendingLinePastes.clear();
       clearTerminalBroadcastUserInput(ctx.sessionId);
       resizeScheduler.dispose();
+      ligatures.dispose();
       webglController.dispose();
       term.element?.removeEventListener("copy", handleNativeCopy, true);
       ctx.container.removeEventListener("copy", handleNativeCopy, true);

components/terminal/runtime/terminalFontLigatures.test.ts

@@ -0,0 +1,149 @@
+import assert from "node:assert/strict";
+import test from "node:test";
+import { readFileSync } from "node:fs";
+
+import { LigaturesAddon } from "@xterm/addon-ligatures";
+
+import {
+  createTerminalLigatureController,
+  terminalFontLigaturesEnabled,
+  type TerminalLigatureAddon,
+} from "./terminalFontLigatures";
+
+class FakeAddon implements TerminalLigatureAddon {
+  disposeCalls = 0;
+
+  dispose() {
+    this.disposeCalls += 1;
+  }
+}
+
+function createHarness(webglActive = false) {
+  const events: string[] = [];
+  const addons: FakeAddon[] = [];
+  const warnings: string[] = [];
+  let failLoad = false;
+
+  const controller = createTerminalLigatureController({
+    createAddon: () => {
+      const addon = new FakeAddon();
+      addons.push(addon);
+      events.push("create");
+      return addon;
+    },
+    loadAddon: () => {
+      events.push("load");
+      if (failLoad) throw new Error("load failed");
+    },
+    isWebglActive: () => webglActive,
+    recreateWebgl: () => {
+      events.push("recreate");
+    },
+    repaint: () => {
+      events.push("repaint");
+    },
+    warn: (message) => warnings.push(message),
+  });
+
+  return {
+    controller,
+    events,
+    addons,
+    warnings,
+    setWebglActive(active: boolean) {
+      webglActive = active;
+    },
+    failNextLoad() {
+      failLoad = true;
+    },
+  };
+}
+
+test("the ligatures addon can be constructed for this xterm version", () => {
+  const addon = new LigaturesAddon();
+  assert.equal(typeof addon.activate, "function");
+  assert.equal(typeof addon.dispose, "function");
+  addon.dispose();
+});
+
+test("font ligatures follow the terminal setting and default on", () => {
+  assert.equal(terminalFontLigaturesEnabled(undefined), true);
+  assert.equal(terminalFontLigaturesEnabled({}), true);
+  assert.equal(terminalFontLigaturesEnabled({ fontLigatures: true }), true);
+  assert.equal(terminalFontLigaturesEnabled({ fontLigatures: false }), false);
+});
+
+test("enabling ligatures before WebGL exists does not rebuild the renderer", () => {
+  const harness = createHarness(false);
+
+  harness.controller.apply(false);
+  assert.deepEqual(harness.events, []);
+
+  harness.controller.apply(true);
+  assert.deepEqual(harness.events, ["create", "load", "repaint"]);
+
+  harness.controller.apply(true);
+  assert.deepEqual(harness.events, ["create", "load", "repaint"]);
+});
+
+test("toggling ligatures rebuilds an active WebGL renderer after the addon updates", () => {
+  const harness = createHarness(true);
+
+  harness.controller.apply(true);
+  assert.deepEqual(harness.events, ["create", "load", "recreate", "repaint"]);
+
+  harness.controller.apply(false);
+  assert.equal(harness.addons[0]?.disposeCalls, 1);
+  assert.deepEqual(harness.events, [
+    "create",
+    "load",
+    "recreate",
+    "repaint",
+    "recreate",
+    "repaint",
+  ]);
+});
+
+test("a failed ligature load leaves WebGL untouched so the terminal can still render", () => {
+  const harness = createHarness(true);
+  harness.failNextLoad();
+
+  harness.controller.apply(true);
+
+  assert.equal(harness.addons[0]?.disposeCalls, 1);
+  assert.deepEqual(harness.events, ["create", "load"]);
+  assert.deepEqual(harness.warnings, ["[XTerm] Ligatures addon failed to load"]);
+});
+
+test("the terminal runtime activates ligatures before the first WebGL load", () => {
+  const runtimeSource = readFileSync(new URL("./createXTermRuntime.ts", import.meta.url), "utf8");
+  const effectsSource = readFileSync(new URL("../useTerminalEffects.ts", import.meta.url), "utf8");
+  const settingsSource = readFileSync(
+    new URL("../../settings/tabs/SettingsTerminalTab.tsx", import.meta.url),
+    "utf8",
+  );
+
+  const applyIndex = runtimeSource.indexOf(
+    "ligatures.apply(terminalFontLigaturesEnabled(settings))",
+  );
+  const firstWebglLoad = runtimeSource.indexOf("loadWebglRenderer()", applyIndex);
+  assert.notEqual(applyIndex, -1);
+  assert.notEqual(firstWebglLoad, -1);
+  assert.ok(
+    firstWebglLoad > applyIndex,
+    "font-feature-settings must be on the terminal element before WebGL creates its glyph atlas",
+  );
+
+  const disposeBodyStart = runtimeSource.indexOf("dispose: () => {");
+  const disposeBody = runtimeSource.slice(disposeBodyStart);
+  const ligatureDispose = disposeBody.indexOf("ligatures.dispose()");
+  const termDispose = disposeBody.indexOf("term.dispose()");
+  assert.notEqual(ligatureDispose, -1);
+  assert.ok(ligatureDispose < termDispose, "release the joiner before xterm tears down the element");
+
+  assert.match(
+    effectsSource,
+    /syncFontLigatures\(\s*terminalFontLigaturesEnabled\(terminalSettings\),\s*\)/,
+  );
+  assert.match(settingsSource, /updateTerminalSetting\("fontLigatures", v\)/);
+});

components/terminal/runtime/terminalFontLigatures.ts

@@ -0,0 +1,82 @@
+export interface TerminalLigatureAddon {
+  dispose(): void;
+}
+
+export function terminalFontLigaturesEnabled(
+  settings: { fontLigatures?: boolean } | null | undefined,
+): boolean {
+  return settings?.fontLigatures !== false;
+}
+
+interface TerminalLigatureControllerOptions {
+  createAddon: () => TerminalLigatureAddon;
+  loadAddon: (addon: TerminalLigatureAddon) => void;
+  isWebglActive: () => boolean;
+  recreateWebgl: () => void;
+  repaint: () => void;
+  warn?: (message: string, error?: unknown) => void;
+}
+
+/**
+ * Owns the ligatures addon for one terminal.
+ *
+ * The addon writes `font-feature-settings` onto the terminal element. WebGL
+ * copies that onto its glyph atlas only when the atlas canvas is created, so
+ * an already-running WebGL renderer has to be rebuilt after the setting
+ * changes. Hidden panes that have not created WebGL yet just keep the CSS in
+ * place for the deferred load.
+ */
+export function createTerminalLigatureController(
+  options: TerminalLigatureControllerOptions,
+) {
+  let addon: TerminalLigatureAddon | null = null;
+  let enabled = false;
+
+  const apply = (nextEnabled: boolean) => {
+    if (nextEnabled === enabled) return;
+
+    if (nextEnabled) {
+      const created = options.createAddon();
+      try {
+        options.loadAddon(created);
+      } catch (error) {
+        try {
+          created.dispose();
+        } catch {
+          // Keep the original load error.
+        }
+        options.warn?.("[XTerm] Ligatures addon failed to load", error);
+        return;
+      }
+      addon = created;
+      enabled = true;
+    } else {
+      try {
+        addon?.dispose();
+      } catch (error) {
+        options.warn?.("[XTerm] Ligatures addon failed to dispose", error);
+      }
+      addon = null;
+      enabled = false;
+    }
+
+    if (options.isWebglActive()) {
+      options.recreateWebgl();
+    }
+    options.repaint();
+  };
+
+  return {
+    apply,
+    dispose: () => {
+      const current = addon;
+      addon = null;
+      enabled = false;
+      try {
+        current?.dispose();
+      } catch (error) {
+        options.warn?.("[XTerm] Ligatures addon failed to dispose", error);
+      }
+    },
+  };
+}

components/terminal/terminalCursorRuntimeLifecycle.test.tsx

@@ -65,6 +65,7 @@ const createContext = (term: ReturnType<typeof createTerm>, terminalSettings: Re
     keywordHighlighter: { setRules: noop },
     cursorLineHighlighter: { setBackgroundColor: noop, setEnabled: noop },
     clearTextureAtlas: noop,
+    syncFontLigatures: noop,
     ensureWebglRenderer: async () => undefined,
     dispose: noop,
   };

components/terminal/useTerminalEffects.ts

@@ -7,6 +7,7 @@ import { resolveFontWeightBold } from '../../lib/fontWeightAvailability';
 import { bundledFamiliesInStack } from '../../lib/fontAvailability';
 import { isMacPlatform } from '../../lib/utils';
 import { resolveXTermScrollback } from '../../infrastructure/config/xtermPerformance';
+import { terminalFontLigaturesEnabled } from './runtime/terminalFontLigatures';
 import {
   createMacOptionForcedSelectionMouseEvent,
   createRightClickMouseTrackingPressClaim,
@@ -1190,6 +1191,9 @@ export function useTerminalEffects(ctx: TerminalEffectsContext) {
       termRef.current.options.altClickMovesCursor = altKeyOpts.altClickMovesCursor;
       termRef.current.options.wordSeparator = terminalSettings.wordSeparators;
       termRef.current.options.ignoreBracketedPasteMode = terminalSettings.disableBracketedPaste ?? false;
+      xtermRuntimeRef.current?.syncFontLigatures(
+        terminalFontLigaturesEnabled(terminalSettings),
+      );
     }
 
     // Changing the font can leave the WebGL renderer drawing stale glyphs from

domain/terminalSettings.test.ts

@@ -177,6 +177,14 @@ test("normalizeTerminalSettings enables font smoothing by default", () => {
   assert.equal(normalizeTerminalSettings().fontSmoothing, true);
 });
 
+test("normalizeTerminalSettings enables font ligatures by default", () => {
+  assert.equal(normalizeTerminalSettings().fontLigatures, true);
+});
+
+test("normalizeTerminalSettings preserves disabled font ligatures", () => {
+  assert.equal(normalizeTerminalSettings({ fontLigatures: false }).fontLigatures, false);
+});
+
 test("normalizeTerminalSettings enables terminal auto-close by default", () => {
   assert.equal(normalizeTerminalSettings().autoCloseOnExit, true);
 });

infrastructure/shims/nodeDiagnosticsChannel.ts

@@ -0,0 +1,24 @@
+// @xterm/addon-ligatures bundles lru-cache, which imports
+// node:diagnostics_channel for optional metrics. The renderer has no Node
+// builtins. Nothing subscribes, so publish and tracePromise stay unused.
+
+const silentChannel = {
+  hasSubscribers: false,
+  publish() {},
+};
+
+export function channel(): typeof silentChannel {
+  return silentChannel;
+}
+
+export function tracingChannel(): {
+  hasSubscribers: boolean;
+  tracePromise: () => Promise<void>;
+} {
+  return {
+    hasSubscribers: false,
+    tracePromise() {
+      return Promise.resolve();
+    },
+  };
+}

package-lock.json

@@ -47,6 +47,7 @@
         "@withfig/autocomplete": "^2.692.3",
         "@xterm/addon-fit": "0.12.0-beta.292",
         "@xterm/addon-image": "0.10.0-beta.292",
+        "@xterm/addon-ligatures": "0.11.0-beta.292",
         "@xterm/addon-search": "0.17.0-beta.292",
         "@xterm/addon-serialize": "0.15.0-beta.292",
         "@xterm/addon-unicode-graphemes": "0.5.0-beta.292",
@@ -9218,6 +9219,31 @@
         "@xterm/xterm": "^6.1.0-beta.292"
       }
     },
+    "node_modules/@xterm/addon-ligatures": {
+      "version": "0.11.0-beta.292",
+      "resolved": "https://registry.npmjs.org/@xterm/addon-ligatures/-/addon-ligatures-0.11.0-beta.292.tgz",
+      "integrity": "sha512-C9DaNn/E1SJh+gULgtT8Js2fz/8QIJ1LvmDXsMMayzvrL72g1kvFOYZSXAcmYveID3eIOIQKyecStfvFR7HU6A==",
+      "license": "MIT",
+      "dependencies": {
+        "lru-cache": "^11.3.6",
+        "opentype.js": "^2.0.0"
+      },
+      "engines": {
+        "node": ">8.0.0"
+      },
+      "peerDependencies": {
+        "@xterm/xterm": "^6.1.0-beta.292"
+      }
+    },
+    "node_modules/@xterm/addon-ligatures/node_modules/lru-cache": {
+      "version": "11.5.3",
+      "resolved": "https://registry.npmjs.org/lru-cache/-/lru-cache-11.5.3.tgz",
+      "integrity": "sha512-U4N8FgzmWxc8k1VH8Kr6lQg18U7Fjvby6wXHVRX/ZZ7IwWbRMgrRbP0Wrb5q5NVinryp4SQampHKdvtecItxUg==",
+      "license": "BlueOak-1.0.0",
+      "engines": {
+        "node": "20 || >=22"
+      }
+    },
     "node_modules/@xterm/addon-search": {
       "version": "0.17.0-beta.292",
       "resolved": "https://registry.npmjs.org/@xterm/addon-search/-/addon-search-0.17.0-beta.292.tgz",
@@ -16505,6 +16531,15 @@
         "url": "https://github.com/sponsors/sindresorhus"
       }
     },
+    "node_modules/opentype.js": {
+      "version": "2.0.0",
+      "resolved": "https://registry.npmjs.org/opentype.js/-/opentype.js-2.0.0.tgz",
+      "integrity": "sha512-kCyjv6xdDY1W/jLWZ/L3QhhTlKUqDZMQ5+Jdlw12b3dXkKNpYBqqlMMj0YDQPShWFTMwgZI1hG14kN3XUDSg/A==",
+      "license": "MIT",
+      "bin": {
+        "ot": "bin/ot"
+      }
+    },
     "node_modules/optionator": {
       "version": "0.9.4",
       "resolved": "https://registry.npmjs.org/optionator/-/optionator-0.9.4.tgz",

package.json

@@ -107,6 +107,7 @@
     "@withfig/autocomplete": "^2.692.3",
     "@xterm/addon-fit": "0.12.0-beta.292",
     "@xterm/addon-image": "0.10.0-beta.292",
+    "@xterm/addon-ligatures": "0.11.0-beta.292",
     "@xterm/addon-search": "0.17.0-beta.292",
     "@xterm/addon-serialize": "0.15.0-beta.292",
     "@xterm/addon-unicode-graphemes": "0.5.0-beta.292",

scripts/terminal-background-rendering.live.test.cjs

@@ -20,18 +20,30 @@ if (!process.versions.electron) {
     fs.rmSync(userData, { recursive: true, force: true });
     app.exit(code);
   };
-  const bundle = esbuild.buildSync({
-    stdin: {
-      contents: [
-        'export {createXTermRuntime} from "./components/terminal/runtime/createXTermRuntime";',
-        'export {DEFAULT_TERMINAL_SETTINGS} from "./domain/models/terminal";',
-        'export {resolveInactiveTerminalPaneStyle} from "./components/terminalPaneVisibility";',
-      ].join("\n"),
-      loader: "ts", resolveDir: root,
-    },
-    bundle: true, format: "cjs", platform: "browser", target: "chrome148", write: false,
-    define: { "import.meta.env.DEV": "false", "import.meta.env.PROD": "true", "import.meta": "{}" },
-  }).outputFiles[0].text;
+  let bundle;
+  try {
+    bundle = esbuild.buildSync({
+      stdin: {
+        contents: [
+          'export {createXTermRuntime} from "./components/terminal/runtime/createXTermRuntime";',
+          'export {DEFAULT_TERMINAL_SETTINGS} from "./domain/models/terminal";',
+          'export {resolveInactiveTerminalPaneStyle} from "./components/terminalPaneVisibility";',
+        ].join("\n"),
+        loader: "ts", resolveDir: root,
+      },
+      bundle: true, format: "cjs", platform: "browser", target: "chrome148", write: false,
+      // addon-ligatures bundles lru-cache's node:diagnostics_channel import.
+      alias: {
+        "node:diagnostics_channel": path.join(root, "infrastructure/shims/nodeDiagnosticsChannel.ts"),
+        "diagnostics_channel": path.join(root, "infrastructure/shims/nodeDiagnosticsChannel.ts"),
+      },
+      define: { "import.meta.env.DEV": "false", "import.meta.env.PROD": "true", "import.meta": "{}" },
+    }).outputFiles[0].text;
+  } catch (error) {
+    console.error(error);
+    fs.rmSync(userData, { recursive: true, force: true });
+    process.exit(1);
+  }
   void app.whenReady().then(async () => {
     win = new BrowserWindow({
       show: true, width: 1100, height: 740,

scripts/terminal-command-period.live.test.cjs

@@ -18,14 +18,27 @@ if (!process.versions.electron || process.platform !== "darwin") {
     fs.rmSync(userData, { recursive: true, force: true });
     app.exit(code);
   };
-  const bundle = require("esbuild").buildSync({
-    stdin: {
-      contents: 'export {createXTermRuntime} from "./components/terminal/runtime/createXTermRuntime"; export {DEFAULT_TERMINAL_SETTINGS} from "./domain/models/terminal"; export {dispatchKittyKeyboardBroadcastInput} from "./components/terminal/runtime/kittyKeyboardBroadcast";',
-      loader: "ts", resolveDir: path.resolve(__dirname, ".."),
-    },
-    bundle: true, format: "cjs", platform: "browser", write: false,
-    define: { "import.meta.env.DEV": "false", "import.meta.env.PROD": "true", "import.meta": "{}" },
-  }).outputFiles[0].text;
+  const root = path.resolve(__dirname, "..");
+  let bundle;
+  try {
+    bundle = require("esbuild").buildSync({
+      stdin: {
+        contents: 'export {createXTermRuntime} from "./components/terminal/runtime/createXTermRuntime"; export {DEFAULT_TERMINAL_SETTINGS} from "./domain/models/terminal"; export {dispatchKittyKeyboardBroadcastInput} from "./components/terminal/runtime/kittyKeyboardBroadcast";',
+        loader: "ts", resolveDir: root,
+      },
+      bundle: true, format: "cjs", platform: "browser", write: false,
+      // addon-ligatures bundles lru-cache's node:diagnostics_channel import.
+      alias: {
+        "node:diagnostics_channel": path.join(root, "infrastructure/shims/nodeDiagnosticsChannel.ts"),
+        "diagnostics_channel": path.join(root, "infrastructure/shims/nodeDiagnosticsChannel.ts"),
+      },
+      define: { "import.meta.env.DEV": "false", "import.meta.env.PROD": "true", "import.meta": "{}" },
+    }).outputFiles[0].text;
+  } catch (error) {
+    console.error(error);
+    fs.rmSync(userData, { recursive: true, force: true });
+    process.exit(1);
+  }
   void app.whenReady().then(async () => {
     win = new BrowserWindow({
       show: true, width: 1000, height: 600,

vite.config.ts

@@ -104,6 +104,7 @@ export default defineConfig(() => {
                 '@xterm/xterm',
                 '@xterm/addon-fit',
                 '@xterm/addon-image',
+                '@xterm/addon-ligatures',
                 '@xterm/addon-search',
                 '@xterm/addon-serialize',
                 '@xterm/addon-web-links',
@@ -136,6 +137,10 @@ export default defineConfig(() => {
       resolve: {
         alias: {
           '@': path.resolve(__dirname, '.'),
+          // The ligatures addon pulls lru-cache's node:diagnostics_channel import
+          // into the renderer bundle. Stub it; the cache never publishes metrics.
+          'node:diagnostics_channel': path.resolve(__dirname, 'infrastructure/shims/nodeDiagnosticsChannel.ts'),
+          'diagnostics_channel': path.resolve(__dirname, 'infrastructure/shims/nodeDiagnosticsChannel.ts'),
         }
       }
     };