refactor: extracted terminal data dispatch into dispatchTerminalInput()

Author: qorzj

src/tests/promptInputKeys.test.ts

@@ -20,11 +20,23 @@ import {
   renderBufferWithCursor,
   buildInitPromptSubmission,
   buildPromptDraftFromSessionMessage,
+  dispatchTerminalInput,
   disableTerminalExtendedKeys,
   enableTerminalExtendedKeys,
+  EMPTY_BUFFER,
+  insertText,
+  backspace,
 } from "../ui";
 import type { SessionMessage, SkillInfo } from "../session";
 
+function collectDispatchedInput(data: string) {
+  const events: ReturnType<typeof parseTerminalInput>[] = [];
+  dispatchTerminalInput(data, (input, key) => {
+    events.push({ input, key });
+  });
+  return events;
+}
+
 test("parseTerminalInput treats DEL bytes as backspace", () => {
   const { input, key } = parseTerminalInput("\u007F");
   assert.equal(input, "");
@@ -72,6 +84,45 @@ test("parseTerminalInput keeps DEL payload for meta+backspace", () => {
   assert.equal(key.backspace, false);
 });
 
+test("dispatchTerminalInput splits iOS CJK composition packets", () => {
+  const events = collectDispatchedInput("가\u007F나");
+  assert.equal(events.length, 3);
+  assert.equal(events[0]?.input, "가");
+  assert.equal(events[1]?.input, "");
+  assert.equal(events[1]?.key.backspace, true);
+  assert.equal(events[2]?.input, "나");
+});
+
+test("dispatchTerminalInput applies multi-step CJK composition to the prompt buffer", () => {
+  let state = EMPTY_BUFFER;
+  dispatchTerminalInput("ㄱ\u007F가\u007F각", (input, key) => {
+    if (key.backspace) {
+      state = backspace(state);
+      return;
+    }
+    state = insertText(state, input);
+  });
+
+  assert.equal(state.text, "각");
+  assert.equal(state.cursor, 1);
+});
+
+test("dispatchTerminalInput preserves meta+backspace as one event", () => {
+  const events = collectDispatchedInput("\u001B\u007F");
+  assert.equal(events.length, 1);
+  assert.equal(events[0]?.input, "\u007F");
+  assert.equal(events[0]?.key.meta, true);
+  assert.equal(events[0]?.key.backspace, false);
+  assert.equal(events[0]?.key.escape, false);
+});
+
+test("dispatchTerminalInput emits consecutive backspaces from one packet", () => {
+  const events = collectDispatchedInput("\u007F\u007F");
+  assert.equal(events.length, 2);
+  assert.equal(events[0]?.key.backspace, true);
+  assert.equal(events[1]?.key.backspace, true);
+});
+
 test("parseTerminalInput keeps BS payload for meta+backspace", () => {
   const { input, key } = parseTerminalInput("\u001B\b");
   assert.equal(input, "\b");

src/ui/PromptInput.tsx

@@ -42,7 +42,7 @@ import { readClipboardImageAsync } from "./clipboard";
 import type { SessionEntry, SkillInfo } from "../session";
 
 // Re-exported from prompt modules for backward compatibility
-export { useTerminalInput, parseTerminalInput } from "./prompt";
+export { useTerminalInput, parseTerminalInput, dispatchTerminalInput } from "./prompt";
 export type { InputKey } from "./prompt";
 
 import { useTerminalInput } from "./prompt";

src/ui/index.ts

@@ -30,6 +30,7 @@ export {
   MODEL_COMMAND_THINKING_OPTIONS,
   useTerminalInput,
   parseTerminalInput,
+  dispatchTerminalInput,
   type PromptSubmission,
   type PromptDraft,
   type InputKey,

src/ui/prompt/index.ts

@@ -1,4 +1,4 @@
-export { useTerminalInput, parseTerminalInput } from "./useTerminalInput";
+export { useTerminalInput, parseTerminalInput, dispatchTerminalInput } from "./useTerminalInput";
 export type { InputKey } from "./useTerminalInput";
 
 export {

src/ui/prompt/useTerminalInput.ts

@@ -169,6 +169,37 @@ export function parseTerminalInput(data: Buffer | string): { input: string; key:
   return { input, key };
 }
 
+export function dispatchTerminalInput(
+  data: Buffer | string,
+  inputHandler: (input: string, key: InputKey) => void
+): void {
+  const raw = String(data);
+
+  // Fix CJK composition bug on iOS terminals (Moshi, Blink, etc.).
+  // iOS keyboards can send composed characters as a single packet like:
+  //   "가\x7f나"  (character + backspace + replacement character)
+  // Do not split escape-prefixed sequences such as Alt+Backspace.
+  if (!raw.startsWith("\u001B") && raw.includes("\x7f") && raw.length > 1) {
+    const parts = raw.split("\x7f");
+    if (parts[0]) {
+      const { input, key } = parseTerminalInput(parts[0]);
+      inputHandler(input, key);
+    }
+    for (let i = 1; i < parts.length; i++) {
+      const bs = parseTerminalInput("\x7f");
+      inputHandler(bs.input, bs.key);
+      if (parts[i]) {
+        const { input, key } = parseTerminalInput(parts[i]);
+        inputHandler(input, key);
+      }
+    }
+    return;
+  }
+
+  const { input, key } = parseTerminalInput(data);
+  inputHandler(input, key);
+}
+
 export function useTerminalInput(
   inputHandler: (input: string, key: InputKey) => void,
   options: { isActive?: boolean } = {}
@@ -193,32 +224,7 @@ export function useTerminalInput(
       return;
     }
     const handleData = (data: Buffer | string) => {
-      const raw = String(data);
-
-      // Fix CJK composition bug on iOS terminals (Moshi, Blink, etc.).
-      // iOS keyboards send composed characters as a single packet like:
-      //   "가\x7f나"  (character + backspace + new character)
-      // Without splitting, parseTerminalInput treats the whole packet as
-      // one input and drops the composition backspaces, corrupting the text.
-      if (raw.includes("\x7f") && raw.length > 1) {
-        const parts = raw.split("\x7f");
-        if (parts[0]) {
-          const { input, key } = parseTerminalInput(parts[0]);
-          handlerRef.current(input, key);
-        }
-        for (let i = 1; i < parts.length; i++) {
-          const bs = parseTerminalInput("\x7f");
-          handlerRef.current(bs.input, bs.key);
-          if (parts[i]) {
-            const { input, key } = parseTerminalInput(parts[i]);
-            handlerRef.current(input, key);
-          }
-        }
-        return;
-      }
-
-      const { input, key } = parseTerminalInput(data);
-      handlerRef.current(input, key);
+      dispatchTerminalInput(data, handlerRef.current);
     };
 
     stdin?.on("data", handleData);