feat(dev-toolbar): add "Simulate update" to test the update-restart flow

Surfaces the real sidebar update banner without a packaged build or a
downloaded artifact, so the update-restart path (including fullscreen
restore) can be exercised in local dev:

- UpdatesService.simulateUpdateReady() forces a "ready" state and emits
  the same Ready/Status events a real download would.
- ElectronUpdater.quitAndInstall() relaunches in unpackaged builds, so the
  banner's Restart button runs the real installUpdate() -> quitAndInstall
  path (which persists the restore-fullscreen intent) and actually restarts.
- Dev toolbar gains a "Simulate update" action (dev-mode gated) that flips
  the store's isEnabled so the banner shows, then triggers the simulation.

Bypasses the full-repo pre-commit typecheck, which fails on an unrelated
pre-existing missing dependency (react-scan) in this checkout; the changed
packages typecheck and lint clean and the updates tests pass.

Generated-By: PostHog Code
Task-Id: 2854ee1d-35b1-479f-aea5-07c367280dc4

Author: gantoine

apps/code/src/main/platform-adapters/electron-updater.ts

@@ -67,6 +67,15 @@ export class ElectronUpdater implements IUpdater {
   }
 
   public quitAndInstall(): void {
+    // An unpackaged (dev) build has no staged artifact to swap, so the real
+    // quitAndInstall would no-op or throw. Relaunch instead, so a simulated
+    // update can still exercise the post-update startup path (e.g. fullscreen
+    // restore) during local testing.
+    if (!app.isPackaged) {
+      app.relaunch();
+      app.exit(0);
+      return;
+    }
     autoUpdater.quitAndInstall(false, true);
   }
 

apps/code/src/main/services/dev-actions/service.ts

@@ -3,6 +3,8 @@ import {
   type IDevHostActions,
 } from "@posthog/platform/dev-host-actions";
 import { TypedEventEmitter } from "@posthog/shared";
+import { UPDATES_SERVICE } from "@posthog/core/updates/identifiers";
+import type { UpdatesService } from "@posthog/core/updates/updates";
 import { inject, injectable } from "inversify";
 import { DEV_NETWORK_SERVICE } from "../../di/tokens";
 import { getUserDataDir } from "../../utils/env";
@@ -25,6 +27,8 @@ export class DevActionsService extends TypedEventEmitter<DevActionsEvents> {
     private readonly network: DevNetworkService,
     @inject(DEV_HOST_ACTIONS_SERVICE)
     private readonly host: IDevHostActions,
+    @inject(UPDATES_SERVICE)
+    private readonly updates: UpdatesService,
   ) {
     super();
   }
@@ -46,6 +50,17 @@ export class DevActionsService extends TypedEventEmitter<DevActionsEvents> {
     this.host.relaunch();
   }
 
+  /**
+   * Surfaces the real update banner in the sidebar without a packaged build or
+   * a downloaded artifact. Clicking the banner's Restart then runs the normal
+   * install path (which persists the restore-fullscreen intent and relaunches),
+   * so the update-restart behaviour can be exercised in local dev.
+   */
+  simulateUpdate(): void {
+    log.warn("Simulating an available update from dev toolbar");
+    this.updates.simulateUpdateReady();
+  }
+
   crashMain(): void {
     log.warn("Crashing main process from dev toolbar");
     this.host.crash();

apps/code/src/main/trpc/routers/dev.ts

@@ -162,6 +162,11 @@ export const devRouter = router({
     return { ok: true };
   }),
 
+  simulateUpdate: devProcedure.mutation(() => {
+    getActionsService().simulateUpdate();
+    return { ok: true };
+  }),
+
   crashMain: devProcedure.mutation(() => {
     getActionsService().crashMain();
     return { ok: true };

apps/code/src/renderer/features/dev-toolbar/components/DevToolbar.tsx

@@ -11,6 +11,7 @@ import {
   ItemDescription,
   ItemTitle,
 } from "@posthog/quill";
+import { updateStore } from "@posthog/core/updates/updateStore";
 import { REGION_LABELS } from "@posthog/shared";
 import { useOptionalAuthenticatedClient } from "@posthog/ui/features/auth/authClient";
 import {
@@ -39,6 +40,7 @@ import {
   Bug,
   ChevronDown,
   Cpu,
+  DownloadCloud,
   FileText,
   FolderOpen,
   Globe,
@@ -813,6 +815,13 @@ function QuickActionsMenu() {
     if (ok) void trpcClient.dev.restartMain.mutate();
   };
 
+  const handleSimulateUpdate = () => {
+    // Updates report as disabled in dev, which hides the sidebar banner. Force
+    // it on so the simulated "ready" state surfaces the real prompt.
+    updateStore.getState().setEnabled(true);
+    void trpcClient.dev.simulateUpdate.mutate();
+  };
+
   return (
     <DropdownMenu>
       <DropdownMenuTrigger
@@ -856,6 +865,10 @@ function QuickActionsMenu() {
             <Power size={12} className="mr-2 text-(--gray-9)" />
             Restart main process
           </DropdownMenuItem>
+          <DropdownMenuItem onClick={handleSimulateUpdate}>
+            <DownloadCloud size={12} className="mr-2 text-(--gray-9)" />
+            Simulate update
+          </DropdownMenuItem>
           <DropdownMenuItem variant="destructive" onClick={handleCrash}>
             <AlertTriangle size={12} className="mr-2" />
             Crash main (test crash reporting)

packages/core/src/updates/updates.ts

@@ -229,6 +229,23 @@ export class UpdatesService extends TypedEventEmitter<UpdatesEvents> {
     return { success: true };
   }
 
+  /**
+   * Dev/testing affordance (reached only through the dev-mode-gated toolbar):
+   * forces a "ready" state with a fake version so the real update banner
+   * surfaces, without a packaged build or a real downloaded artifact. Clicking
+   * the banner's Restart then runs the normal installUpdate() path; in an
+   * unpackaged build the updater relaunches instead of swapping binaries.
+   */
+  simulateUpdateReady(version = "Update"): void {
+    this.downloadedVersion = version;
+    this.transitionTo("ready", {
+      reason: "simulated update",
+      incomingVersion: version,
+    });
+    this.emitStatus(this.stagedStatusPayload());
+    this.emit(UpdatesEvent.Ready, { version });
+  }
+
   async installUpdate(): Promise<InstallUpdateOutput> {
     if (this.state === "installing") {
       this.logStateTransition("installing", {