Add in-app updater for Linux

[ivan-ottinger]

Related issues

Part of RSM-1314 — Linux release prep.

How AI was used in this PR

AI-assisted: drafted the Linux branch in apps/studio/src/updates.ts, the unit tests, and this PR body. Author reviewed.

Proposed Changes

Adds Linux support to the in-app update flow. Electron's built-in autoUpdater is macOS/Windows only, so this PR adds a custom polling branch in apps/studio/src/updates.ts that hits the same WPCOM endpoint, parses the agreed Linux response, and shows an OS dialog when an update is available. The dialog has a Download button that opens the user's browser to the .deb URL via shellOpenExternalWrapper; the user installs manually via sudo apt install.

Response handling

Server response	Client behavior
200 { version, downloadUrl }	Show dialog with the new version + Download/Later buttons. On Download, validate URL is http:/https: then open via shellOpenExternalWrapper. Reschedule.
204	No update. Silent on auto-poll; "No updates available" dialog on manual check (shared with Mac/Windows).
404	Should not happen. Log to Sentry and treat as no-op.
Other errors	Log to Sentry. Reschedule.

The server runs version_compare() and returns 204 when the client is current, so the client trusts the response without further comparison.

Out of scope

• Linux dev/release distribution to AppsCDN — tracked in #3464 and RSM-2587. This PR is independent: the WPCOM studio-app/updates endpoint is already deployed and serves Linux responses today.
• Automatic install — .deb installation requires root, can't be silent. Flow is intentionally "open browser, user installs."

Testing Instructions

Automated: unit tests cover the three main response paths (200, 204, server error). They run in CI; locally:

npx vitest run apps/studio/src/tests/updates.test.ts

Visual verification of the dialog on Linux: because no Linux release exists in AppsCDN yet, the server returns 204 for any version. To exercise the dialog locally, apply this temporary diff to force-trigger the 200 path, then revert when done. Run on a Linux machine (or VM):

git checkout add-linux-in-app-updater
git apply <<'PATCH'
diff --git a/apps/studio/src/updates.ts b/apps/studio/src/updates.ts
--- a/apps/studio/src/updates.ts
+++ b/apps/studio/src/updates.ts
@@ -222,6 +222,12 @@ async function showUpdateReadyToInstallNotice() {
 }
 
 function setupLinuxUpdates() {
+	// TEMP for local testing — REMOVE BEFORE COMMIT
+	console.log( 'TEMP: bypassing shouldPoll for local Linux updater test' );
+	void pollLinuxUpdates();
+	return;
+	// END TEMP
+
 	if ( ! shouldPoll ) {
 		console.log( 'Skipping Linux auto-updates', {
 			env: process.env.NODE_ENV,
@@ -238,6 +244,22 @@ function setupLinuxUpdates() {
 async function pollLinuxUpdates() {
 	updaterState = 'checking-for-update';
 
+	// TEMP for local testing — REMOVE BEFORE COMMIT
+	// Stubs a fake 200 response so the dialog renders without a real WPCOM call.
+	// Swap to `return;` (in the try) to test the 204 path instead.
+	console.log( 'TEMP: stubbing fake 200 response' );
+	try {
+		await showLinuxUpdateAvailableNotice(
+			'1.9.9',
+			'https://appscdn.wordpress.com/downloads/wordpress-com-studio/linux-arm64/v1.9.9/update/studio_1.9.9_arm64.deb'
+		);
+	} finally {
+		showManualCheckDialogs = false;
+		rescheduleLinuxOrFinish();
+	}
+	return;
+	// END TEMP
+
 	const url = new URL( 'https://public-api.wordpress.com/wpcom/v2/studio-app/updates' );
 	url.searchParams.append( 'platform', process.platform );
 	url.searchParams.append( 'studioArch', process.arch );
PATCH
npm start

Within ~1 second of the main window appearing, the dialog should render. Verify:

• Title "New Version Available", message "Studio 1.9.9 is available".
• Install command on its own line: sudo apt install ~/Downloads/studio_1.9.9_arm64.deb.
• Click "Download" → browser opens to the URL (it'll 404 — that's expected; verifying shellOpenExternalWrapper fires).
• Click "Later" → dialog dismisses.
• Help → Check for Updates triggers the same dialog.

When done, revert:

git checkout apps/studio/src/updates.ts

No regression on Mac/Windows: npm start on Mac or Windows should behave exactly as before this PR (no entry into the Linux branch).

Pre-merge Checklist

• Have you checked for TypeScript, React or other console errors?
• Unit tests pass (npx vitest run apps/studio/src/tests/updates.test.ts).
• Visual smoke test on a Linux machine confirms the dialog renders correctly.
• Mac/Windows update flow is unchanged.

[Copilot]

Pull request overview

Adds Linux support to Studio’s in-app update flow by bypassing Electron’s platform-limited autoUpdater and implementing a custom polling + dialog-based update prompt on Linux.

Changes:

• Add a Linux-specific update path in setupUpdates() that polls the WPCOM studio-app/updates endpoint and shows a “Download / Later” dialog with manual install instructions.
• Implement Linux polling/rescheduling logic and .deb filename extraction for the apt install hint.
• Add Vitest unit tests covering the primary Linux response paths (200/204/error) via manualCheckForUpdates().

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 3 comments.

File	Description
apps/studio/src/updates.ts	Adds Linux polling updater branch, update-available dialog, and rescheduling logic.
apps/studio/src/tests/updates.test.ts	Adds unit tests validating Linux updater dialog behavior and error reporting.

Comments suppressed due to low confidence (1)

apps/studio/src/updates.ts:295

• rescheduleLinuxOrFinish() assigns a new setTimeout without clearing any existing one. If pollLinuxUpdates() can be entered concurrently (e.g., via repeated manual checks), multiple timers may accumulate and cause bursts of polling. Clear any existing timeout (and set it back to null) before scheduling the next poll.

function rescheduleLinuxOrFinish() {
	if ( ! shouldPoll ) {
		updaterState = 'done';
		return;
	}
	updaterState = 'polling';
	timeout = setTimeout( () => {
		console.log( 'Automatically polling for Linux update' );
		void pollLinuxUpdates();
	}, AUTO_UPDATE_INTERVAL_MS );
}

---

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[Copilot]

Pull request overview

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

[wpmobilebot]

📊 Performance Test Results

Comparing 5f18545 vs trunk

app-size

Metric	trunk	5f18545	Diff	Change
App Size (Mac)	1409.64 MB	1409.65 MB	+0.01 MB	⚪ 0.0%

site-editor

Metric	trunk	5f18545	Diff	Change
load	1478 ms	1499 ms	+21 ms	⚪ 0.0%

site-startup

Metric	trunk	5f18545	Diff	Change
siteCreation	8591 ms	8594 ms	+3 ms	⚪ 0.0%
siteStartup	4923 ms	4929 ms	+6 ms	⚪ 0.0%

---

Results are median values from multiple test runs.

Legend: 🟢 Improvement (faster) | 🔴 Regression (slower) | ⚪ No change (<50ms diff)

[gavande1]

Tested locally on Linux using the temp-patch flow from the testing instructions — the dialog renders correctly with the version, install command, and working Download link. LGTM!