fix(update): launch installers after the current app exits

tests/app-shell.test.tsx

@@ -65,6 +65,14 @@ describe("desktop shell", () => {
     expect(sparklineBlock).toContain("window.setInterval(tick, 750)");
   });
 
+  it("quits promptly after handing the update to the deferred installer launcher", () => {
+    const source = readFileSync(new URL("../src/main/main.ts", import.meta.url), "utf8");
+    const install = source.slice(source.indexOf("handleTrusted(IPC_CHANNELS.INSTALL_UPDATE"), source.indexOf("handleTrusted(IPC_CHANNELS.OPEN_EXTERNAL"));
+
+    expect(install).toContain("}, 250)");
+    expect(install).not.toContain("}, 5000)");
+  });
+
   it("does not let live download snapshots overwrite the local column order", () => {
     const source = readFileSync(new URL("../src/renderer/App.tsx", import.meta.url), "utf8");
     const stateUpdates = source.slice(source.indexOf("unsubscribe = window.rd.onStateUpdate"), source.indexOf("unsubClipboard = window.rd.onClipboardDetected"));

tests/product-metadata.test.ts

@@ -31,6 +31,17 @@ describe("Multi-Debrid-Downloader product metadata", () => {
     expect(supportBundle).toContain("mdd-support-bundle-");
   });
 
+  it("packages an update-safe NSIS process handoff for older app versions", () => {
+    const packageJson = JSON.parse(fs.readFileSync(path.resolve("package.json"), "utf8"));
+    const installer = fs.readFileSync(path.resolve("resources", "installer.nsh"), "utf8");
+
+    expect(packageJson.build.nsis.include).toBe("resources/installer.nsh");
+    expect(installer).toContain("!macro customCheckAppRunning");
+    expect(installer).toContain("${isUpdated}");
+    expect(installer).toContain("FIND_PROCESS");
+    expect(installer).toContain("taskkill /f /im");
+  });
+
   it("moves the legacy user data directory without losing runtime state", () => {
     const root = fs.mkdtempSync(path.join(os.tmpdir(), "mdd-user-data-"));
     tempDirs.push(root);

tests/public-release-metadata.test.ts

@@ -142,9 +142,10 @@ function createReleaseFixture(): string {
           to: "assets/app_icon.ico"
         }
       ],
-      nsis: {
-        artifactName: "${productName}-Setup-${version}.${ext}",
-        oneClick: false,
+      nsis: {
+        artifactName: "${productName}-Setup-${version}.${ext}",
+        include: "resources/installer.nsh",
+        oneClick: false,
         perMachine: false,
         allowToChangeInstallationDirectory: true,
         createDesktopShortcut: true
@@ -171,6 +172,7 @@ function createReleaseFixture(): string {
   writeRedistributionFiles(rootDir, true);
   writeFile(rootDir, "assets/app_icon.ico", "application-icon");
   writeFile(rootDir, "win-unpacked/resources/assets/app_icon.ico", "application-icon");
+  writeFile(rootDir, "resources/installer.nsh", "!macro customCheckAppRunning\n${isUpdated}\nFIND_PROCESS\ntaskkill /f /im\n!macroend\n");
 
   return rootDir;
 }
@@ -196,7 +198,7 @@ describe("public release metadata", () => {
     expect(result.missingArtifacts).toEqual([]);
   });
 
-  it("rejects a package configured for a different GitHub owner", () => {
+  it("rejects a package configured for a different GitHub owner", () => {
     const rootDir = createReleaseFixture();
     const packagePath = path.join(rootDir, "package.json");
     const packageJson = JSON.parse(fs.readFileSync(packagePath, "utf8"));
@@ -345,6 +347,16 @@ describe("public release metadata", () => {
     expect(() => verifyPublicRelease(rootDir)).toThrow(/extraResources|LICENSE/);
   });
 
+  it("rejects release metadata without the update-safe NSIS include", () => {
+    const rootDir = createReleaseFixture();
+    const packagePath = path.join(rootDir, "package.json");
+    const packageJson = JSON.parse(fs.readFileSync(packagePath, "utf8"));
+    delete packageJson.build.nsis.include;
+    fs.writeFileSync(packagePath, `${JSON.stringify(packageJson, null, 2)}\n`);
+
+    expect(() => verifyPublicRelease(rootDir)).toThrow(/NSIS|update|installer/i);
+  });
+
   it("rejects a packaged application without its window and tray icon", () => {
     const rootDir = createReleaseFixture();
     fs.rmSync(path.join(rootDir, "win-unpacked", "resources", "assets", "app_icon.ico"));

tests/update-launch-order.test.ts

@@ -0,0 +1,58 @@
+import fs from "node:fs";
+import os from "node:os";
+import path from "node:path";
+import { spawn } from "node:child_process";
+import { afterEach, describe, expect, it } from "vitest";
+import { buildDeferredInstallerLaunch } from "../src/main/update";
+
+const tempDirs: string[] = [];
+
+afterEach(() => {
+  for (const dir of tempDirs.splice(0)) {
+    fs.rmSync(dir, { recursive: true, force: true });
+  }
+});
+
+async function waitForFile(filePath: string, timeoutMs: number): Promise<void> {
+  const deadline = Date.now() + timeoutMs;
+  while (!fs.existsSync(filePath)) {
+    if (Date.now() >= deadline) {
+      throw new Error("marker timeout");
+    }
+    await new Promise((resolve) => setTimeout(resolve, 50));
+  }
+}
+
+describe.runIf(process.platform === "win32")("deferred update launch", () => {
+  it("starts the installer only after the previous application process exits", async () => {
+    const root = fs.mkdtempSync(path.join(os.tmpdir(), "mdd-update-launch-"));
+    tempDirs.push(root);
+    const installerPath = path.join(root, "installer.cmd");
+    const markerPath = path.join(root, "started.txt");
+    fs.writeFileSync(installerPath, `@echo off\r\n> "${markerPath}" echo started\r\n`, "utf8");
+    const previous = spawn(process.env.ComSpec || "cmd.exe", ["/d", "/s", "/c", "ping 127.0.0.1 -n 3 > nul"], {
+      stdio: "ignore",
+      windowsHide: true
+    });
+    if (!previous.pid) {
+      throw new Error("previous process missing pid");
+    }
+    const deferred = buildDeferredInstallerLaunch(installerPath, previous.pid);
+    const launcher = spawn(deferred.command, deferred.args, {
+      stdio: "ignore",
+      windowsHide: true
+    });
+
+    await new Promise((resolve) => setTimeout(resolve, 500));
+    expect(fs.existsSync(markerPath)).toBe(false);
+
+    await new Promise<void>((resolve, reject) => {
+      previous.once("exit", () => resolve());
+      previous.once("error", reject);
+    });
+    await waitForFile(markerPath, 5_000);
+    expect(fs.readFileSync(markerPath, "utf8").trim()).toBe("started");
+
+    launcher.unref();
+  });
+});

tests/update.test.ts

@@ -22,7 +22,7 @@ vi.mock("node:child_process", () => ({
   spawn: spawnMock
 }));
 
-import { buildInstallerLaunchArgs, checkGitHubUpdate, installLatestUpdate, isRemoteNewer, normalizeUpdateRepo, parseVersionParts } from "../src/main/update";
+import { buildDeferredInstallerLaunch, buildInstallerLaunchArgs, checkGitHubUpdate, installLatestUpdate, isRemoteNewer, normalizeUpdateRepo, parseVersionParts } from "../src/main/update";
 import { APP_VERSION } from "../src/main/constants";
 import { UpdateCheckResult, UpdateInstallProgress } from "../src/shared/types";
 
@@ -154,9 +154,27 @@ describe("update", () => {
     ].join("\n"));
   });
 
-  it("uses silent NSIS install flags with auto-run after update", () => {
-    expect(buildInstallerLaunchArgs()).toEqual(["/S", "--updated", "--force-run"]);
-  });
+  it("uses silent NSIS install flags with auto-run after update", () => {
+    expect(buildInstallerLaunchArgs()).toEqual(["/S", "--updated", "--force-run"]);
+  });
+
+  it("defers the installer until the current application process has exited", () => {
+    const launch = buildDeferredInstallerLaunch("C:\\Temp\\MDD Update\\setup.exe", 4242, "C:\\Windows");
+    const encoded = launch.args.at(-1) || "";
+    const script = Buffer.from(encoded, "base64").toString("utf16le");
+
+    expect(launch.command).toBe("C:\\Windows\\System32\\WindowsPowerShell\\v1.0\\powershell.exe");
+    expect(launch.args.slice(0, -1)).toEqual([
+      "-NoLogo",
+      "-NoProfile",
+      "-NonInteractive",
+      "-WindowStyle",
+      "Hidden",
+      "-EncodedCommand"
+    ]);
+    expect(script.indexOf("Get-Process -Id 4242")).toBeLessThan(script.indexOf("Start-Process -FilePath 'C:\\Temp\\MDD Update\\setup.exe'"));
+    expect(script).toContain("@('/S','--updated','--force-run')");
+  });
 
   it("falls back to alternate download URL when setup asset URL returns 404", async () => {
     const executablePayload = fs.readFileSync(process.execPath);
@@ -567,8 +585,8 @@ describe("update", () => {
     });
 
     expect(result.started).toBe(true);
-    expect(spawnMock).toHaveBeenCalledWith(expect.any(String), ["/S", "--updated", "--force-run"], expect.objectContaining({
-      detached: true,
+    expect(spawnMock).toHaveBeenCalledWith(expect.stringMatching(/powershell\.exe$/i), expect.arrayContaining(["-EncodedCommand"]), expect.objectContaining({
+      detached: true,
       stdio: "ignore",
       windowsHide: true
     }));