fix(selection): clear editor highlight when selection chip is deleted (#93)

Clicking the X on a captured selection chip removes the token from the
composer input. The SelectionController noticed this and dropped the stored
selection, but it forgot to clear the mock highlight shown in the editor
(or preview CSS highlight). The highlight would linger because storedSelection
was already null by the time any cleanup ran.

Call clearHighlight() before nulling storedSelection so the CM6/CSS highlight
is removed together with the chip.

Author: luoxuanzao

src/features/chat/controllers/selection-controller.ts

@@ -438,6 +438,7 @@ export class SelectionController {
     if (this.storedToken) {
       if (!value.includes(this.storedToken)) {
         const stale = this.storedToken;
+        this.clearHighlight();
         this.storedToken = null;
         this.storedSelection = null;
         this.tokenSink.unregister(stale);

tests/unit/features/chat/controllers/selection-controller.test.ts

@@ -157,7 +157,7 @@ describe('SelectionController', () => {
     expect(showSelectionHighlight).toHaveBeenCalledWith(editorView, 0, 4);
   });
 
-  it('drops the stored selection when the token is removed from the input', () => {
+  it('drops the stored selection and clears the highlight when the token is removed from the input', () => {
     controller.start();
     jest.advanceTimersByTime(250);
     expect(controller.hasSelection()).toBe(true);
@@ -167,6 +167,7 @@ describe('SelectionController', () => {
 
     expect(controller.hasSelection()).toBe(false);
     expect(tokenSink.unregister).toHaveBeenCalledWith(SOURCE_TOKEN);
+    expect(hideSelectionHighlight).toHaveBeenCalledWith(editorView);
   });
 
   it('collapses the editor selection on send so the chip does not come back', () => {
@@ -606,6 +607,29 @@ describe('SelectionController', () => {
       expect(mockHighlights.delete).toHaveBeenCalledWith('qoderian-selection');
     });
 
+    it('clears CSS highlight when the selection chip token is removed in reading mode', () => {
+      const anchorNode = {};
+      (global as any).document = {
+        activeElement: null,
+        getSelection: jest.fn().mockReturnValue(
+          createMockDOMSelection('reading selection', anchorNode),
+        ),
+      };
+      const mockHighlights = { set: jest.fn(), delete: jest.fn() };
+      (global as any).CSS = { highlights: mockHighlights };
+
+      controller.start();
+      jest.advanceTimersByTime(250);
+      expect(controller.hasSelection()).toBe(true);
+
+      inputEl.value = '';
+      inputEl.dispatchEvent(new Event('input', { bubbles: true }));
+
+      expect(controller.hasSelection()).toBe(false);
+      expect(tokenSink.unregister).toHaveBeenCalledWith('@notes/reading.md');
+      expect(mockHighlights.delete).toHaveBeenCalledWith('qoderian-selection');
+    });
+
     it('skips CSS highlight for disconnected DOM ranges', () => {
       const anchorNode = {};
       const mockSel = createMockDOMSelection('reading selection', anchorNode);