fix(editor): collapse the workspace split when the last buffer closes (T-459)

EditorRegistry.close() guarded its active-changed emit on `_activeId != null`, so closing the LAST buffer (active clears to null) emitted only editor.closed — never the active-changed(id:null) the editor extension listens for to call closeEditor(). editorOpen stayed true and the top split sat orphaned over the Claude pane. Always emit active-changed when the active buffer is removed, including the cleared-to-null case; the slot renderer already collapses correctly once editorOpen flips false. The existing extension test fabricated the null active-changed event, so it passed despite the registry never emitting it — that gap is why the bug shipped. Add a registry test that drives the real close() path, plus a slot_host widget test asserting the split (drag handle) drops out and the primary pane fills the column. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
2026-06-22 17:49:12 +02:00
parent 8c9c881d81
commit 1e49f3e1d9
6 changed files with 188 additions and 1 deletions
@@ -0,0 +1,81 @@
+/// T-459: the workspace editor top split must collapse cleanly when the
+/// editor closes — no orphaned drag handle or empty region left over the
+/// primary (Claude) pane.
+///
+/// This covers the render seam: given `arrangement.editorOpen`, the
+/// `_WorkspaceSlot` either shows the split (editor body + drag handle over the
+/// primary pane) or collapses to just the primary pane. The event seam that
+/// flips `editorOpen` on the last buffer close is covered by the registry +
+/// editor-extension tests.
+library;
+
+import 'package:clide/extension/extension.dart';
+import 'package:clide/kernel/kernel.dart';
+import 'package:clide/src/shell/slot_host.dart';
+import 'package:flutter/widgets.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+import '../../helpers/kernel_fixture.dart';
+import '../../helpers/widget_harness.dart';
+
+void main() {
+  late KernelFixture f;
+
+  setUp(() async {
+    f = await KernelFixture.create();
+    // Stand-in workspace tabs: the real Claude pane / EditorView pull in PTY +
+    // tree-sitter FFI, which the split-collapse contract doesn't need.
+    f.services.panels.contribute(
+      TabContribution(
+        id: 'claude.primary',
+        slot: Slots.workspace,
+        title: 'Claude',
+        priority: 90,
+        build: (_) => const SizedBox(key: ValueKey('claude-body')),
+      ),
+    );
+    f.services.panels.contribute(
+      TabContribution(
+        id: 'editor.active',
+        slot: Slots.workspace,
+        title: 'Editor',
+        priority: 80,
+        build: (_) => const SizedBox(key: ValueKey('editor-body')),
+      ),
+    );
+  });
+  tearDown(() => f.dispose());
+
+  Finder dragHandle() => find.bySemanticsLabel('Editor split');
+
+  testWidgets('editor top split collapses to the primary pane when the editor closes (T-459)', (tester) async {
+    // Editor open + active: the split shows the editor body, the drag handle,
+    // and the primary pane below.
+    f.services.panels.activateTab(Slots.workspace, 'editor.active');
+    f.services.arrangement.openEditor();
+    await tester.pumpWidget(harness(f, const SlotHost(slot: Slots.workspace)));
+    await tester.pump();
+
+    expect(dragHandle(), findsOneWidget, reason: 'split should render its resize handle while the editor is open');
+    expect(find.byKey(const ValueKey('editor-body')), findsOneWidget);
+    expect(find.byKey(const ValueKey('claude-body')), findsOneWidget);
+
+    // Close the editor → the top split must drop out entirely, leaving only the
+    // primary pane (no leftover drag handle / empty region).
+    f.services.arrangement.closeEditor();
+    await tester.pump();
+
+    expect(dragHandle(), findsNothing, reason: 'collapsed split must not leave a drag handle behind');
+    expect(find.byKey(const ValueKey('editor-body')), findsNothing, reason: 'closed editor body must not linger');
+    expect(find.byKey(const ValueKey('claude-body')), findsOneWidget, reason: 'primary pane fills the column');
+  });
+
+  testWidgets('no split when the editor was never opened — primary pane only', (tester) async {
+    f.services.panels.activateTab(Slots.workspace, 'claude.primary');
+    await tester.pumpWidget(harness(f, const SlotHost(slot: Slots.workspace)));
+    await tester.pump();
+
+    expect(dragHandle(), findsNothing);
+    expect(find.byKey(const ValueKey('claude-body')), findsOneWidget);
+  });
+}