feat: Support Alt+key combinations (#10767)

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

@@ -956,3 +956,127 @@ describe('Drag and Drop Handling', () => {
     });
   });
 });
+
+describe('Terminal-specific Alt+key combinations', () => {
+  let stdin: MockStdin;
+  const mockSetRawMode = vi.fn();
+
+  const wrapper = ({ children }: { children: React.ReactNode }) => (
+    <KeypressProvider kittyProtocolEnabled={true}>{children}</KeypressProvider>
+  );
+
+  beforeEach(() => {
+    vi.clearAllMocks();
+    stdin = new MockStdin();
+    (useStdin as Mock).mockReturnValue({
+      stdin,
+      setRawMode: mockSetRawMode,
+    });
+  });
+
+  // Terminals to test
+  const terminals = ['iTerm2', 'Ghostty', 'MacTerminal', 'VSCodeTerminal'];
+
+  // Key mappings: letter -> [keycode, accented character, shouldHaveMeta]
+  // Note: µ (mu) is sent with meta:false on iTerm2/VSCode
+  const keys: Record<string, [number, string, boolean]> = {
+    a: [97, 'å', true],
+    o: [111, 'ø', true],
+    m: [109, 'µ', false],
+  };
+
+  it.each(
+    terminals.flatMap((terminal) =>
+      Object.entries(keys).map(
+        ([key, [keycode, accentedChar, shouldHaveMeta]]) => {
+          if (terminal === 'Ghostty') {
+            // Ghostty uses kitty protocol sequences
+            return {
+              terminal,
+              key,
+              kittySequence: `\x1b[${keycode};3u`,
+              expected: {
+                name: key,
+                ctrl: false,
+                meta: true,
+                shift: false,
+                paste: false,
+                kittyProtocol: true,
+              },
+            };
+          } else if (terminal === 'MacTerminal') {
+            // Mac Terminal sends ESC + letter
+            return {
+              terminal,
+              key,
+              input: {
+                sequence: `\x1b${key}`,
+                name: key,
+                ctrl: false,
+                meta: true,
+                shift: false,
+                paste: false,
+              },
+              expected: {
+                sequence: `\x1b${key}`,
+                name: key,
+                ctrl: false,
+                meta: true,
+                shift: false,
+                paste: false,
+              },
+            };
+          } else {
+            // iTerm2 and VSCode send accented characters (å, ø, µ)
+            // Note: µ comes with meta:false but gets converted to m with meta:true
+            return {
+              terminal,
+              key,
+              input: {
+                name: key,
+                ctrl: false,
+                meta: shouldHaveMeta,
+                shift: false,
+                paste: false,
+                sequence: accentedChar,
+              },
+              expected: {
+                name: key,
+                ctrl: false,
+                meta: true, // Always expect meta:true after conversion
+                shift: false,
+                paste: false,
+                sequence: accentedChar,
+              },
+            };
+          }
+        },
+      ),
+    ),
+  )(
+    'should handle Alt+$key in $terminal',
+    ({
+      kittySequence,
+      input,
+      expected,
+    }: {
+      kittySequence?: string;
+      input?: Partial<Key>;
+      expected: Partial<Key>;
+    }) => {
+      const keyHandler = vi.fn();
+      const { result } = renderHook(() => useKeypressContext(), { wrapper });
+      act(() => result.current.subscribe(keyHandler));
+
+      if (kittySequence) {
+        act(() => stdin.sendKittySequence(kittySequence));
+      } else if (input) {
+        act(() => stdin.pressKey(input));
+      }
+
+      expect(keyHandler).toHaveBeenCalledWith(
+        expect.objectContaining(expected),
+      );
+    },
+  );
+});