Fix Web Audio context selection when a context is destroyed and add tests

Bug: 414631999
Change-Id: I941765d2356875f0b7c3b748742b713b6b8d3725
Reviewed-on: https://chromium-review.googlesource.com/c/devtools/devtools-frontend/+/6870539
Auto-Submit: Danil Somsikov <[email protected]>
Reviewed-by: Benedikt Meurer <[email protected]>
Commit-Queue: Danil Somsikov <[email protected]>

Author: danilsomsikov

front_end/panels/web_audio/WebAudioView.test.ts

@@ -189,4 +189,59 @@ describeWithMockConnection('WebAudioView', () => {
     const input = await view.nextInput;
     assert.strictEqual(input.selectedContextIndex, 1);
   });
+
+  it('keeps context selected when another is destroyed', async () => {
+    const view = createViewFunctionStub(WebAudio.WebAudioView.WebAudioView);
+    renderElementIntoDOM(new WebAudio.WebAudioView.WebAudioView(undefined, view));
+    const target = createTarget();
+    const model = target.model(WebAudio.WebAudioModel.WebAudioModel);
+    assert.exists(model);
+
+    model.dispatchEventToListeners(WebAudio.WebAudioModel.Events.CONTEXT_CREATED, context1);
+    await view.nextInput;
+    model.dispatchEventToListeners(WebAudio.WebAudioModel.Events.CONTEXT_CREATED, context2);
+    await view.nextInput;
+
+    model.dispatchEventToListeners(WebAudio.WebAudioModel.Events.CONTEXT_DESTROYED, context2.contextId);
+    const input = await view.nextInput;
+
+    assert.deepEqual(input.contexts, [context1]);
+    assert.strictEqual(input.selectedContextIndex, 0);
+  });
+
+  it('selects another context when the selected one is destroyed', async () => {
+    const view = createViewFunctionStub(WebAudio.WebAudioView.WebAudioView);
+    renderElementIntoDOM(new WebAudio.WebAudioView.WebAudioView(undefined, view));
+    const target = createTarget();
+    const model = target.model(WebAudio.WebAudioModel.WebAudioModel);
+    assert.exists(model);
+
+    model.dispatchEventToListeners(WebAudio.WebAudioModel.Events.CONTEXT_CREATED, context1);
+    await view.nextInput;
+    model.dispatchEventToListeners(WebAudio.WebAudioModel.Events.CONTEXT_CREATED, context2);
+    await view.nextInput;
+
+    model.dispatchEventToListeners(WebAudio.WebAudioModel.Events.CONTEXT_DESTROYED, context1.contextId);
+    const input = await view.nextInput;
+
+    assert.deepEqual(input.contexts, [context2]);
+    assert.strictEqual(input.selectedContextIndex, 0);
+  });
+
+  it('selects nothing when the only context is destroyed', async () => {
+    const view = createViewFunctionStub(WebAudio.WebAudioView.WebAudioView);
+    renderElementIntoDOM(new WebAudio.WebAudioView.WebAudioView(undefined, view));
+    const target = createTarget();
+    const model = target.model(WebAudio.WebAudioModel.WebAudioModel);
+    assert.exists(model);
+
+    model.dispatchEventToListeners(WebAudio.WebAudioModel.Events.CONTEXT_CREATED, context1);
+    await view.nextInput;
+
+    model.dispatchEventToListeners(WebAudio.WebAudioModel.Events.CONTEXT_DESTROYED, context1.contextId);
+    const input = await view.nextInput;
+
+    assert.isEmpty(input.contexts);
+    assert.strictEqual(input.selectedContextIndex, -1);
+  });
 });

front_end/panels/web_audio/WebAudioView.ts

@@ -267,8 +267,12 @@ export class WebAudioView extends UI.Widget.VBox implements SDK.TargetManager.SD
       const selectedContext =
           this.selectedContextIndex > -1 ? this.contextSelectorItems.at(this.selectedContextIndex) : null;
       this.contextSelectorItems.remove(index);
-      this.selectedContextIndex =
-          selectedContext ? this.contextSelectorItems.indexOf(selectedContext) : this.contextSelectorItems.length - 1;
+      const newSelectedIndex = selectedContext ? this.contextSelectorItems.indexOf(selectedContext) : -1;
+      if (newSelectedIndex > -1) {
+        this.selectedContextIndex = newSelectedIndex;
+      } else {
+        this.selectedContextIndex = Math.min(index, this.contextSelectorItems.length - 1);
+      }
     }
     this.requestUpdate();
   }