fix(editor): open the launched file when the window restores its last tabs (#1594)

Starting OpenIDEA with a file showed the last session's tabs without the file: restoring the saved tabs counted as the user activating another tab, so the pending open of the launched file was dropped as superseded. Restoring a session no longer counts as an activation; the launched file opens next to the restored tabs and becomes active (also for a file opened with its project at startup).

src/editor/core/controller.test.ts

@@ -262,6 +262,24 @@ describe("EditorController", () => {
     useProject.setState({ lightEdit: false });
   });
 
+  it("opens a file requested while the LightEdit session is being restored", async () => {
+    ctrl = new EditorController(createMemoryBackend({ "/x/a.txt": "a", "/y/b.md": "b", "/z/launch.lua": "l" }));
+    ctrl.start();
+    useProject.setState({ lightEdit: true });
+    await ctrl.openFile("/x/a.txt", { focus: false });
+    await ctrl.openFile("/y/b.md", { focus: false });
+    useProject.setState({ lightEdit: false });
+    // A launch with a file path: LightEdit starts and the file opens before the old tabs are back.
+    useProject.setState({ lightEdit: true });
+    await ctrl.openFile("/z/launch.lua", { focus: false });
+    expect(openFilePaths(useTabs.getState())).toEqual(["/x/a.txt", "/y/b.md", "/z/launch.lua"]);
+    const s = useTabs.getState();
+    const active = s.panes[s.activePane]!;
+    expect(active.tabs.find((t) => t.id === active.active)?.input.path).toBe("/z/launch.lua");
+    await ctrl.closeEverything();
+    useProject.setState({ lightEdit: false });
+  });
+
   it("closes a tab by its input key", async () => {
     ctrl = new EditorController(createMemoryBackend());
     ctrl.start();

src/editor/core/controller.ts

@@ -237,6 +237,8 @@ export class EditorController implements SlotHost {
   private selectionRequests = new Map<string, number>();
   private activationGeneration = 0;
   private admitting = false;
+  /** Tabs restored from a saved session: not a user's activation, so a pending open still activates its tab. */
+  private restoring = false;
   private closeRequests = 0;
   private projectTransition: Promise<void> = Promise.resolve();
 
@@ -269,6 +271,7 @@ export class EditorController implements SlotHost {
         prevTabs = s;
         if (
           !this.admitting &&
+          !this.restoring &&
           (s.activePane !== prev.activePane || s.panes[s.activePane]?.active !== prev.panes[prev.activePane]?.active)
         )
           ++this.activationGeneration;
@@ -486,7 +489,12 @@ export class EditorController implements SlotHost {
       pane.tabs = pane.tabs.map((tab) => (documentLifecycle(tab.input, kinds) ? { ...tab, preview: false } : tab));
     this.restoredViews = new Map(Object.entries(session.files));
     this.restoredTabs = new Set(Object.values(state.panes).flatMap((p) => p.tabs.map((t) => t.id)));
-    useTabs.setState(state, true);
+    this.restoring = true;
+    try {
+      useTabs.setState(state, true);
+    } finally {
+      this.restoring = false;
+    }
     for (const pane of Object.values(state.panes)) if (pane.active) void this.ensureSlot(pane.active);
   }