Give the desktop smoke test the Electron runtime CI never installed (#426)

.gitea/workflows/ci.yml

@@ -94,11 +94,14 @@ jobs:
         with:
           node-version-file: .nvmrc
 
+      # playwright's chromium set covers everything but GTK, which chromium
+      # only needs headed and electron always links against.
       - name: Install dependencies
         run: |
           corepack enable && pnpm i --frozen-lockfile
           npm ci --prefix electron
           pnpm exec playwright install-deps chromium
+          apt-get install -y libgtk-3-0t64
 
       - name: Build desktop
         run: pnpm run build:desktop

README.md

@@ -72,7 +72,10 @@ or iOS. `dev:desktop` opens those built assets; rerun `build:desktop` after fron
 changes. Live reload is deferred to the desktop configuration work.
 
 Run `pnpm run test:desktop` after building to check the Linux desktop window. On a
-headless Linux runner, use `xvfb-run -a pnpm run test:desktop`. The separate smoke
+headless Linux runner, use `xvfb-run -a pnpm run test:desktop`; Electron links
+against GTK, which Playwright's chromium dependencies do not cover, so such a box
+also needs `libgtk-3-0t64`. The test drops Chromium's sandbox when it runs as
+root, because Chromium refuses to start that way. The separate smoke
 suite does not start a web dev server or test installers. Windows and macOS desktop
 behavior is not verified by the Linux test. CI builds and runs this suite under
 Xvfb in a separate desktop job.

e2e/desktop/smoke.spec.ts

@@ -13,7 +13,8 @@ test("the desktop baseline renders, navigates, and keeps external pages outside"
     )
     const app = await _electron.launch({
       executablePath,
-      chromiumSandbox: true,
+      // Chromium refuses to start as root with its sandbox on, which is what a CI container is.
+      chromiumSandbox: process.getuid?.() !== 0,
       args: [resolve("electron")],
       env: {...process.env, XDG_CONFIG_HOME: profile},
     })

electron/package.json

@@ -6,6 +6,7 @@
   "main": "build/main.js",
   "scripts": {
     "build": "tsc",
+    "postinstall": "install-electron",
     "start": "electron ."
   },
   "devDependencies": {