Fix alt key mappings for mac (#12231)

docs/cli/keyboard-shortcuts.md

@@ -67,3 +67,12 @@ This document lists the available keyboard shortcuts in the Gemini CLI.
 | Shortcut | Description                       |
 | -------- | --------------------------------- |
 | `Ctrl+G` | See context CLI received from IDE |
+
+## Meta+key combos on mac
+
+On Mac, all Meta+char combos should work normally except for these three which
+are mapped to special functionality.
+
+- `meta+b`: "∫" back one word
+- `meta+f`: "ƒ" forward one word
+- `meta+m`: "µ" toggle markup view

packages/cli/src/ui/contexts/KeypressContext.test.tsx

@@ -872,99 +872,118 @@ describe('Kitty Sequence Parsing', () => {
     vi.useRealTimers();
   });
 
-  // Terminals to test
-  const terminals = ['iTerm2', 'Ghostty', 'MacTerminal', 'VSCodeTerminal'];
+  describe('Cross-terminal Alt key handling (simulating macOS)', () => {
+    let originalPlatform: NodeJS.Platform;
 
-  // Key mappings: letter -> [keycode, accented character]
-  const keys: Record<string, [number, string]> = {
-    a: [97, 'å'],
-    o: [111, 'ø'],
-    m: [109, 'µ'],
-  };
-
-  it.each(
-    terminals.flatMap((terminal) =>
-      Object.entries(keys).map(([key, [keycode, accentedChar]]) => {
-        if (terminal === 'Ghostty') {
-          // Ghostty uses kitty protocol sequences
-          return {
-            terminal,
-            key,
-            chunk: `\x1b[${keycode};3u`,
-            expected: {
-              name: key,
-              ctrl: false,
-              meta: true,
-              shift: false,
-              paste: false,
-              kittyProtocol: true,
-            },
-          };
-        } else if (terminal === 'MacTerminal') {
-          // Mac Terminal sends ESC + letter
-          return {
-            terminal,
-            key,
-            kitty: false,
-            chunk: `\x1b${key}`,
-            expected: {
-              sequence: `\x1b${key}`,
-              name: key,
-              ctrl: false,
-              meta: true,
-              shift: false,
-              paste: false,
-            },
-          };
-        } else {
-          // iTerm2 and VSCode send accented characters (å, ø, µ)
-          // Note: µ (mu) is sent with meta:false on iTerm2/VSCode but
-          // gets converted to m with meta:true
-          return {
-            terminal,
-            key,
-            chunk: accentedChar,
-            expected: {
-              name: key,
-              ctrl: false,
-              meta: true, // Always expect meta:true after conversion
-              shift: false,
-              paste: false,
-              sequence: accentedChar,
-            },
-          };
-        }
-      }),
-    ),
-  )(
-    'should handle Alt+$key in $terminal',
-    ({
-      chunk,
-      expected,
-      kitty = true,
-    }: {
-      chunk: string;
-      expected: Partial<Key>;
-      kitty?: boolean;
-    }) => {
-      const keyHandler = vi.fn();
-      const testWrapper = ({ children }: { children: React.ReactNode }) => (
-        <KeypressProvider kittyProtocolEnabled={kitty}>
-          {children}
-        </KeypressProvider>
-      );
-      const { result } = renderHook(() => useKeypressContext(), {
-        wrapper: testWrapper,
+    beforeEach(() => {
+      originalPlatform = process.platform;
+      Object.defineProperty(process, 'platform', {
+        value: 'darwin',
+        configurable: true,
       });
-      act(() => result.current.subscribe(keyHandler));
+    });
 
-      act(() => stdin.write(chunk));
+    afterEach(() => {
+      Object.defineProperty(process, 'platform', {
+        value: originalPlatform,
+        configurable: true,
+      });
+    });
 
-      expect(keyHandler).toHaveBeenCalledWith(
-        expect.objectContaining(expected),
-      );
-    },
-  );
+    // Terminals to test
+    const terminals = ['iTerm2', 'Ghostty', 'MacTerminal', 'VSCodeTerminal'];
+
+    // Key mappings: letter -> [keycode, accented character]
+    const keys: Record<string, [number, string]> = {
+      b: [98, '\u222B'],
+      f: [102, '\u0192'],
+      m: [109, '\u00B5'],
+    };
+
+    it.each(
+      terminals.flatMap((terminal) =>
+        Object.entries(keys).map(([key, [keycode, accentedChar]]) => {
+          if (terminal === 'Ghostty') {
+            // Ghostty uses kitty protocol sequences
+            return {
+              terminal,
+              key,
+              chunk: `\x1b[${keycode};3u`,
+              expected: {
+                name: key,
+                ctrl: false,
+                meta: true,
+                shift: false,
+                paste: false,
+                kittyProtocol: true,
+              },
+            };
+          } else if (terminal === 'MacTerminal') {
+            // Mac Terminal sends ESC + letter
+            return {
+              terminal,
+              key,
+              kitty: false,
+              chunk: `\x1b${key}`,
+              expected: {
+                sequence: `\x1b${key}`,
+                name: key,
+                ctrl: false,
+                meta: true,
+                shift: false,
+                paste: false,
+              },
+            };
+          } else {
+            // iTerm2 and VSCode send accented characters (å, ø, µ)
+            // Note: µ (mu) is sent with meta:false on iTerm2/VSCode but
+            // gets converted to m with meta:true
+            return {
+              terminal,
+              key,
+              chunk: accentedChar,
+              expected: {
+                name: key,
+                ctrl: false,
+                meta: true, // Always expect meta:true after conversion
+                shift: false,
+                paste: false,
+                sequence: accentedChar,
+              },
+            };
+          }
+        }),
+      ),
+    )(
+      'should handle Alt+$key in $terminal',
+      ({
+        chunk,
+        expected,
+        kitty = true,
+      }: {
+        chunk: string;
+        expected: Partial<Key>;
+        kitty?: boolean;
+      }) => {
+        const keyHandler = vi.fn();
+        const testWrapper = ({ children }: { children: React.ReactNode }) => (
+          <KeypressProvider kittyProtocolEnabled={kitty}>
+            {children}
+          </KeypressProvider>
+        );
+        const { result } = renderHook(() => useKeypressContext(), {
+          wrapper: testWrapper,
+        });
+        act(() => result.current.subscribe(keyHandler));
+
+        act(() => stdin.write(chunk));
+
+        expect(keyHandler).toHaveBeenCalledWith(
+          expect.objectContaining(expected),
+        );
+      },
+    );
+  });
 
   describe('Backslash key handling', () => {
     beforeEach(() => {

packages/cli/src/ui/contexts/KeypressContext.tsx

@@ -48,33 +48,12 @@ export const PASTE_CODE_TIMEOUT_MS = 50; // Flush incomplete paste code after 50
 export const SINGLE_QUOTE = "'";
 export const DOUBLE_QUOTE = '"';
 
-const ALT_KEY_CHARACTER_MAP: Record<string, string> = {
-  '\u00E5': 'a',
-  '\u222B': 'b',
-  '\u00E7': 'c',
-  '\u2202': 'd',
-  '\u00B4': 'e',
-  '\u0192': 'f',
-  '\u00A9': 'g',
-  '\u02D9': 'h',
-  '\u02C6': 'i',
-  '\u2206': 'j',
-  '\u02DA': 'k',
-  '\u00AC': 'l',
-  '\u00B5': 'm',
-  '\u02DC': 'n',
-  '\u00F8': 'o',
-  '\u03C0': 'p',
-  '\u0153': 'q',
-  '\u00AE': 'r',
-  '\u00DF': 's',
-  '\u2020': 't',
-  '\u00A8': 'u',
-  '\u221A': 'v',
-  '\u2211': 'w',
-  '\u2248': 'x',
-  '\u00A5': 'y',
-  '\u03A9': 'z',
+// On Mac, hitting alt+char will yield funny characters.
+// Remap these three since we listen for them.
+const MAC_ALT_KEY_CHARACTER_MAP: Record<string, string> = {
+  '\u222B': 'b', // "∫" back one word
+  '\u0192': 'f', // "ƒ" forward one word
+  '\u00B5': 'm', // "µ" toggle markup view
 };
 
 /**
@@ -615,8 +594,8 @@ export function KeypressProvider({
         return;
       }
 
-      const mappedLetter = ALT_KEY_CHARACTER_MAP[key.sequence];
-      if (mappedLetter && !key.meta) {
+      const mappedLetter = MAC_ALT_KEY_CHARACTER_MAP[key.sequence];
+      if (process.platform === 'darwin' && mappedLetter && !key.meta) {
         broadcast({
           name: mappedLetter,
           ctrl: false,