feat(tui): expand paste markers on second paste

.changeset/expand-paste-marker.md

@@ -0,0 +1,5 @@
+---
+"@moonshot-ai/kimi-code": minor
+---
+
+Expand folded paste markers on second paste. When the cursor is on a paste marker (e.g. `[paste #1 +15 lines]`) and the user pastes again, the marker expands back to the original content instead of inserting new clipboard data.

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

@@ -11,6 +11,10 @@ import { createEditorTheme } from '#/tui/theme/pi-tui-theme';
 // oxlint-disable-next-line no-control-regex -- ESC (\x1b) is required to match ANSI SGR escape sequences
 const ANSI_SGR = /\u001B\[[0-9;]*m/g;
 
+const PASTE_MARKER_RE = /\[paste #(\d+)(?: (?:\+\d+ lines|\d+ chars))?\]/g;
+const BRACKET_PASTE_START = '\u001B[200~';
+const BRACKET_PASTE_END = '\u001B[201~';
+
 // Kitty keyboard protocol CSI-u sequence: ESC [ keycode ; modifier[:eventType] u.
 // We intentionally match only the simple two-field form — enough to rewrite
 // `ctrl+<LETTER>` with caps_lock into `ctrl+<letter>` without caps_lock.
@@ -118,6 +122,9 @@ export class CustomEditor extends Editor {
    */
   public onPasteImage?: () => Promise<boolean>;
 
+  private consumingPaste = false;
+  private consumeBuffer = '';
+
   /**
    * `colors` is the live `ColorPalette` reference — the host mutates it
    * in place on theme switch (`Object.assign(state.theme.colors, ...)`), so
@@ -140,6 +147,30 @@ export class CustomEditor extends Editor {
     super(tui, createEditorTheme(colors), { paddingX: 4 });
   }
 
+  private expandPasteMarkerAtCursor(): boolean {
+    const { line, col } = this.getCursor();
+    const lines = this.getLines();
+    const currentLine = lines[line] ?? '';
+
+    for (const match of currentLine.matchAll(PASTE_MARKER_RE)) {
+      const start = match.index;
+      const end = start + match[0].length;
+      if (col < start || col > end) continue;
+
+      const pasteId = Number(match[1]);
+      const pastes = (this as unknown as { pastes: Map<number, string> }).pastes;
+      const content = pastes.get(pasteId);
+      if (content === undefined) return false;
+
+      const text = this.getText();
+      const offset = lines.slice(0, line).reduce((sum, l) => sum + l.length + 1, 0) + start;
+      const newText = text.slice(0, offset) + content + text.slice(offset + match[0].length);
+      this.setText(newText);
+      return true;
+    }
+    return false;
+  }
+
   private hasAutocompleteActivity(): boolean {
     const autocomplete = this as unknown as AutocompleteInternals;
     return (
@@ -190,24 +221,48 @@ export class CustomEditor extends Editor {
     if (isKeyRelease(normalized)) {
       return;
     }
+
+    // When a paste marker was just expanded, discard the trailing bracketed
+    // paste data that the terminal sends alongside the Ctrl-V keystroke.
+    if (this.consumingPaste) {
+      this.consumeBuffer += normalized;
+      if (this.consumeBuffer.includes(BRACKET_PASTE_END)) {
+        this.consumingPaste = false;
+        this.consumeBuffer = '';
+      }
+      return;
+    }
+
+    // If a bracketed paste arrives while the cursor sits on an existing
+    // paste marker, expand that marker instead of pasting new content.
+    if (normalized.includes(BRACKET_PASTE_START) && this.expandPasteMarkerAtCursor()) {
+      if (!normalized.includes(BRACKET_PASTE_END)) {
+        this.consumingPaste = true;
+      }
+      return;
+    }
+
     // Paste image binding — platform-aware:
     //   Windows terminals reserve Ctrl-V for their own paste handling
     //   (e.g. Windows Terminal's Ctrl+V shortcut), so we listen for
     //   Alt-V there. Everywhere else Ctrl-V pastes. When the host
     //   reports no image available, we fall through to pi-tui's
     //   normal paste path so text from the clipboard still works.
     const pasteKey = process.platform === 'win32' ? 'alt+v' : Key.ctrl('v');
-    if (matchesKey(normalized, pasteKey) && this.onPasteImage !== undefined) {
-      const handler = this.onPasteImage;
-      void handler().then((handled) => {
-        if (!handled) {
-          this.onTextPaste?.();
-          // No image on the clipboard — forward the original keystroke
-          // through the base handler so a textual clipboard still works.
-          super.handleInput.call(this, normalized);
-        }
-      });
-      return;
+    if (matchesKey(normalized, pasteKey)) {
+      if (this.expandPasteMarkerAtCursor()) {
+        return;
+      }
+      if (this.onPasteImage !== undefined) {
+        const handler = this.onPasteImage;
+        void handler().then((handled) => {
+          if (!handled) {
+            this.onTextPaste?.();
+            super.handleInput.call(this, normalized);
+          }
+        });
+        return;
+      }
     }
 
     if (matchesKey(normalized, Key.ctrl('d'))) {

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

@@ -84,6 +84,129 @@ describe('CustomEditor Kitty key release handling', () => {
   });
 });
 
+describe('CustomEditor paste marker expansion', () => {
+  const PASTE_START = '\x1b[200~';
+  const PASTE_END = '\x1b[201~';
+
+  function simulateLargePaste(editor: CustomEditor, content: string): void {
+    editor.handleInput(`${PASTE_START}${content}${PASTE_END}`);
+  }
+
+  it('expands paste marker when bracketed paste arrives while cursor is on marker', () => {
+    const editor = makeEditor();
+    const longText = 'line\n'.repeat(15).trimEnd();
+    simulateLargePaste(editor, longText);
+
+    expect(editor.getText()).toMatch(/\[paste #1 \+15 lines\]/);
+
+    simulateLargePaste(editor, 'anything');
+
+    expect(editor.getText()).not.toContain('[paste #');
+    expect(editor.getText()).toContain(longText);
+  });
+
+  it('does not expand when cursor is not on a paste marker', () => {
+    const editor = makeEditor();
+    const longText = 'line\n'.repeat(15).trimEnd();
+    simulateLargePaste(editor, longText);
+
+    editor.handleInput('hello');
+
+    const textBefore = editor.getText();
+    expect(textBefore).toContain('[paste #1');
+    expect(textBefore).toContain('hello');
+
+    const anotherLong = 'other\n'.repeat(15).trimEnd();
+    simulateLargePaste(editor, anotherLong);
+
+    expect(editor.getText()).toContain('[paste #1');
+    expect(editor.getText()).toContain('[paste #2');
+  });
+
+  it('expands only the marker under cursor when multiple markers exist', () => {
+    const editor = makeEditor();
+    const text1 = 'first\n'.repeat(15).trimEnd();
+    const text2 = 'second\n'.repeat(15).trimEnd();
+    simulateLargePaste(editor, text1);
+    editor.handleInput(' ');
+    simulateLargePaste(editor, text2);
+
+    expect(editor.getText()).toContain('[paste #1');
+    expect(editor.getText()).toContain('[paste #2');
+
+    editor.setText('[paste #1 +15 lines] [paste #2 +15 lines]');
+
+    simulateLargePaste(editor, 'anything');
+
+    expect(editor.getText()).toContain('[paste #1');
+    expect(editor.getText()).not.toContain('[paste #2');
+    expect(editor.getText()).toContain(text2);
+  });
+
+  it('handles Ctrl+V expansion when cursor is on marker', () => {
+    const editor = makeEditor();
+    editor.onPasteImage = vi.fn(async () => false);
+    const longText = 'line\n'.repeat(15).trimEnd();
+    simulateLargePaste(editor, longText);
+
+    expect(editor.getText()).toMatch(/\[paste #1/);
+
+    editor.handleInput('\x16');
+
+    expect(editor.getText()).not.toContain('[paste #');
+    expect(editor.getText()).toContain(longText);
+  });
+
+  it('can re-expand after undo restores the marker', () => {
+    const editor = makeEditor();
+    const longText = 'line\n'.repeat(15).trimEnd();
+    simulateLargePaste(editor, longText);
+
+    const markerText = editor.getText();
+    expect(markerText).toMatch(/\[paste #1/);
+
+    simulateLargePaste(editor, 'anything');
+    expect(editor.getText()).toContain(longText);
+
+    editor.setText(markerText);
+
+    simulateLargePaste(editor, 'anything');
+    expect(editor.getText()).not.toContain('[paste #');
+    expect(editor.getText()).toContain(longText);
+  });
+
+  it('suppresses multi-chunk bracketed paste data after marker expansion', () => {
+    const editor = makeEditor();
+    const longText = 'line\n'.repeat(15).trimEnd();
+    simulateLargePaste(editor, longText);
+
+    editor.handleInput(`${PASTE_START}chunk1`);
+    editor.handleInput(`chunk2${PASTE_END}`);
+
+    expect(editor.getText()).not.toContain('chunk1');
+    expect(editor.getText()).not.toContain('chunk2');
+    expect(editor.getText()).toContain(longText);
+  });
+
+  it('handles paste-end sequence split across chunks', () => {
+    const editor = makeEditor();
+    const longText = 'line\n'.repeat(15).trimEnd();
+    simulateLargePaste(editor, longText);
+
+    // Split: PASTE_START in chunk 1, paste-end split across chunk 2 and 3
+    editor.handleInput(`${PASTE_START}data`);
+    editor.handleInput('\x1b[20');
+    editor.handleInput('1~');
+
+    expect(editor.getText()).toContain(longText);
+    expect(editor.getText()).not.toContain('data');
+
+    // Verify editor is not stuck — next keystrokes should work normally
+    editor.handleInput('x');
+    expect(editor.getText()).toContain('x');
+  });
+});
+
 describe('CustomEditor shortcut telemetry hooks', () => {
   it('reports newline shortcuts, including Ctrl-J, before delegating to the base editor', () => {
     const editor = makeEditor();