fix(tui): fix Tab key completion in the editor

.changeset/fix-slash-subcommand-after-tab.md

@@ -0,0 +1,5 @@
+---
+"@moonshot-ai/kimi-code": patch
+---
+
+Show subcommand suggestions after Tab-completing a slash command name.

.changeset/fix-tab-file-completion.md

@@ -0,0 +1,5 @@
+---
+"@moonshot-ai/kimi-code": patch
+---
+
+Fix the Tab key unexpectedly opening the file completion list.

apps/kimi-code/src/tui/components/editor/custom-editor.ts

@@ -404,20 +404,54 @@ export class CustomEditor extends Editor {
       return;
     }
 
+    // Swallow Tab while the autocomplete dropdown is closed so it does not
+    // trigger pi-tui's built-in file completion. When the dropdown is open,
+    // fall through so pi-tui can still accept the selected item with Tab.
+    if (matchesKey(normalized, Key.tab) && !this.isShowingAutocomplete()) {
+      return;
+    }
+
     super.handleInput(normalized);
-    this.reopenPathCompletionAfterInput();
+    this.reopenAutocompleteAfterInput();
   }
 
-  private reopenPathCompletionAfterInput(): void {
+  private reopenAutocompleteAfterInput(): void {
+    if (this.isShowingAutocomplete()) return;
     const { line, col } = this.getCursor();
     const textBeforeCursor = this.getLines()[line]?.slice(0, col) ?? '';
-    if (!textBeforeCursor.endsWith('/')) return;
-    if (this.isShowingAutocomplete()) return;
-    const isSlashArgument = textBeforeCursor.startsWith('/') && textBeforeCursor.includes(' ');
-    const isAtMention = extractAtPrefix(textBeforeCursor) !== null;
-    if (!isSlashArgument && !isAtMention) return;
-    (this as unknown as { requestAutocomplete?: (options: { force: boolean; explicitTab: boolean }) => void })
-      .requestAutocomplete?.({ force: true, explicitTab: false });
+    const editor = this as unknown as {
+      requestAutocomplete?: (options: { force: boolean; explicitTab: boolean }) => void;
+    };
+    if (editor.requestAutocomplete === undefined) return;
+    const trigger = (): void => {
+      // Use force:false so slash-aware logic runs: commands with argument
+      // completions return their subcommands, commands without them return
+      // null. force:true would bypass the slash branch and fall through to
+      // path completion, wrongly popping up the file list.
+      editor.requestAutocomplete?.({ force: false, explicitTab: false });
+    };
+
+    // Reopen path / argument completion right after a `/` is typed
+    // (e.g. `/add-dir /` or an `@dir/` mention).
+    if (textBeforeCursor.endsWith('/')) {
+      const isSlashArgument = textBeforeCursor.startsWith('/') && textBeforeCursor.includes(' ');
+      const isAtMention = extractAtPrefix(textBeforeCursor) !== null;
+      if (isSlashArgument || isAtMention) {
+        trigger();
+      }
+      return;
+    }
+
+    // After accepting a slash command name via Tab, pi-tui inserts a trailing
+    // space and closes the menu without triggering argument completion. Reopen
+    // it so subcommands (e.g. `/goal ` → status/pause/…) show immediately.
+    if (
+      textBeforeCursor.endsWith(' ') &&
+      textBeforeCursor.startsWith('/') &&
+      textBeforeCursor.includes(' ')
+    ) {
+      trigger();
+    }
   }
 }
 

apps/kimi-code/test/tui/components/editor/custom-editor.test.ts

@@ -142,6 +142,73 @@ describe('CustomEditor slash argument completion refresh', () => {
   });
 });
 
+describe('CustomEditor slash command name Tab-accept', () => {
+  it('reopens subcommand completions after Tab-accepting a slash command name', async () => {
+    const editor = makeEditor();
+    const provider = new FileMentionProvider(
+      [
+        {
+          name: 'goal',
+          description: 'Manage goals',
+          getArgumentCompletions: (prefix) =>
+            prefix === ''
+              ? [
+                  { value: 'status', label: 'status' },
+                  { value: 'pause', label: 'pause' },
+                ]
+              : null,
+        },
+      ],
+      process.cwd(),
+      null,
+    );
+    editor.setAutocompleteProvider(provider);
+
+    for (const char of '/go') {
+      editor.handleInput(char);
+    }
+    await new Promise((resolve) => setTimeout(resolve, 20));
+    await flushAutocomplete();
+    expect(editor.isShowingAutocomplete()).toBe(true);
+
+    editor.handleInput('\t');
+    await new Promise((resolve) => setTimeout(resolve, 20));
+    await flushAutocomplete();
+
+    expect(editor.getText()).toBe('/goal ');
+    expect(editor.isShowingAutocomplete()).toBe(true);
+  });
+
+  it('does not fall back to file completions for a command without subcommands', async () => {
+    const editor = makeEditor();
+    const provider = new FileMentionProvider(
+      [
+        {
+          name: 'compact',
+          description: 'Compact context',
+        },
+      ],
+      process.cwd(),
+      null,
+    );
+    editor.setAutocompleteProvider(provider);
+
+    for (const char of '/comp') {
+      editor.handleInput(char);
+    }
+    await new Promise((resolve) => setTimeout(resolve, 20));
+    await flushAutocomplete();
+    expect(editor.isShowingAutocomplete()).toBe(true);
+
+    editor.handleInput('\t');
+    await new Promise((resolve) => setTimeout(resolve, 20));
+    await flushAutocomplete();
+
+    expect(editor.getText()).toBe('/compact ');
+    expect(editor.isShowingAutocomplete()).toBe(false);
+  });
+});
+
 describe('CustomEditor @ mention completion refresh', () => {
   it('reopens the next directory level after tab-accepting an @ directory', async () => {
     const editor = makeEditor();
@@ -200,6 +267,21 @@ describe('CustomEditor @ mention completion refresh', () => {
   });
 });
 
+describe('CustomEditor Tab key handling', () => {
+  it('does not open autocomplete when Tab is pressed with the dropdown closed', async () => {
+    const editor = makeEditor();
+    const provider = providerReturning([{ value: '@src/file.ts', label: 'file.ts' }]);
+    editor.setAutocompleteProvider(provider);
+
+    editor.handleInput('\t');
+    await new Promise((resolve) => setTimeout(resolve, 30));
+    await flushAutocomplete();
+
+    expect(provider.getSuggestions).not.toHaveBeenCalled();
+    expect(editor.isShowingAutocomplete()).toBe(false);
+  });
+});
+
 describe('CustomEditor slash argument hint', () => {
   // oxlint-disable-next-line no-control-regex -- ESC (\u001B) is required to match ANSI SGR escape sequences
   const stripAnsi = (s: string): string => s.replaceAll(/\u001B\[[0-9;]*m/g, '');