fix(tui): route Ctrl+K and Ctrl+W through macOS readline fallback

Makes Ctrl+K and Ctrl+W work in hermes --tui mode in macOS

ui-tui/src/__tests__/platform.test.ts

@@ -30,3 +30,22 @@ describe('platform action modifier', () => {
     expect(isActionMod({ ctrl: false, meta: false, super: true })).toBe(false)
   })
 })
+
+describe('isMacActionFallback', () => {
+  it('routes raw Ctrl+K and Ctrl+W to readline kill-to-end / delete-word on macOS', async () => {
+    const { isMacActionFallback } = await importPlatform('darwin')
+
+    expect(isMacActionFallback({ ctrl: true, meta: false, super: false }, 'k', 'k')).toBe(true)
+    expect(isMacActionFallback({ ctrl: true, meta: false, super: false }, 'w', 'w')).toBe(true)
+    // Must not fire when Cmd (meta/super) is held — those are distinct chords.
+    expect(isMacActionFallback({ ctrl: true, meta: true, super: false }, 'k', 'k')).toBe(false)
+    expect(isMacActionFallback({ ctrl: true, meta: false, super: true }, 'w', 'w')).toBe(false)
+  })
+
+  it('is a no-op on non-macOS (Linux routes Ctrl+K/W through isActionMod directly)', async () => {
+    const { isMacActionFallback } = await importPlatform('linux')
+
+    expect(isMacActionFallback({ ctrl: true, meta: false, super: false }, 'k', 'k')).toBe(false)
+    expect(isMacActionFallback({ ctrl: true, meta: false, super: false }, 'w', 'w')).toBe(false)
+  })
+})

ui-tui/src/components/textInput.tsx

@@ -634,6 +634,8 @@ export function TextInput({
       const actionHome = k.home || (!isMac && mod && inp === 'a') || isMacActionFallback(k, inp, 'a')
       const actionEnd = k.end || (mod && inp === 'e') || isMacActionFallback(k, inp, 'e')
       const actionDeleteToStart = (mod && inp === 'u') || isMacActionFallback(k, inp, 'u')
+      const actionKillToEnd = (mod && inp === 'k') || isMacActionFallback(k, inp, 'k')
+      const actionDeleteWord = (mod && inp === 'w') || isMacActionFallback(k, inp, 'w')
       const range = selRange()
       const delFwd = k.delete || fwdDel.current
 
@@ -697,7 +699,7 @@ export function TextInput({
         } else {
           v = v.slice(0, c) + v.slice(nextPos(v, c))
         }
-      } else if (mod && inp === 'w') {
+      } else if (actionDeleteWord) {
         if (range) {
           v = v.slice(0, range.start) + v.slice(range.end)
           c = range.start
@@ -717,7 +719,7 @@ export function TextInput({
           v = v.slice(c)
           c = 0
         }
-      } else if (mod && inp === 'k') {
+      } else if (actionKillToEnd) {
         if (range) {
           v = v.slice(0, range.start) + v.slice(range.end)
           c = range.start

ui-tui/src/lib/platform.ts

@@ -16,15 +16,18 @@ export const isActionMod = (key: { ctrl: boolean; meta: boolean; super?: boolean
   isMac ? key.meta || key.super === true : key.ctrl
 
 /**
- * Some macOS terminals rewrite Cmd navigation/deletion into readline control keys.
+ * Accept raw Ctrl+<letter> as an action shortcut on macOS, where `isActionMod`
- * Treat those as action shortcuts too, but only for the specific fallbacks we
+ * otherwise means Cmd. Two motivations:
- * have observed from terminals: Cmd+Left → Ctrl+A, Cmd+Right → Ctrl+E,
+ *   - Some macOS terminals rewrite Cmd navigation/deletion into readline control
- * Cmd+Backspace → Ctrl+U.
+ *     keys (Cmd+Left → Ctrl+A, Cmd+Right → Ctrl+E, Cmd+Backspace → Ctrl+U).
+ *   - Ctrl+K (kill-to-end) and Ctrl+W (delete-word-back) are standard readline
+ *     bindings that users expect to work regardless of platform, even though
+ *     no terminal rewrites Cmd into them.
  */
 export const isMacActionFallback = (
   key: { ctrl: boolean; meta: boolean; super?: boolean },
   ch: string,
-  target: 'a' | 'e' | 'u'
+  target: 'a' | 'e' | 'u' | 'k' | 'w'
 ): boolean => isMac && key.ctrl && !key.meta && key.super !== true && ch.toLowerCase() === target
 
 /** Match action-modifier + a single character (case-insensitive). */