[BUG] After executing the electron test, the error "Cannot read properties of undefined (reading 'require')" is reported

[duan602728596]

System info

• Playwright Version: v1.39.0
• Operating System: All
• Browser: Electron
• Other info: Electron Version: v28

After I upgraded the project's Electron version to v28, if I execute the test, I get an error:

Versions less than 28 do not have this error:

Source code

• I provided exact source code that allows reproducing the issue locally.

Link to the GitHub repository with the repro
https://github.com/duan602728596/electron-v28-bug-demo

Steps

• npm install
• npm run test

Expected

Run test success.

Actual

Run test failed.

[mxschmitt]

Full stack:

  1) index.test.mjs:9:3 › App › Should render #app dom ─────────────────────────────────────────────

    Error: TypeError: Cannot read properties of undefined (reading 'require')

        at <anonymous>:1:20
        at CRExecutionContext.rawEvaluateHandle (/Users/maxschmitt/Developer/tmp/electron-v28-bug-demo/node_modules/playwright-core/lib/server/chromium/crExecutionContext.js:58:33)
        at runNextTicks (node:internal/process/task_queues:60:5)
        at processImmediate (node:internal/timers:447:9)
        at LongStandingScope._race (/Users/maxschmitt/Developer/tmp/electron-v28-bug-demo/node_modules/playwright-core/lib/utils/manualPromise.js:98:14)
        at CRSession.<anonymous> (/Users/maxschmitt/Developer/tmp/electron-v28-bug-demo/node_modules/playwright-core/lib/server/electron/electron.js:68:13)

Good npm install electron-nightly@28.0.0-nightly.20230828
Bad npm install electron-nightly@28.0.0-nightly.20230831

RANGE: electron/electron@v28.0.0-nightly.20230828...v28.0.0-nightly.20230831

Repro: PWDEBUGIMPL=1 npm run etest electron/electron-app.spec.ts:22:5 with:

diff --git a/package.json b/package.json
index d489bedaa..aa41f0434 100644
--- a/package.json
+++ b/package.json
@@ -82,6 +82,7 @@
     "cross-env": "^7.0.3",
     "dotenv": "^16.0.0",
     "electron": "19.0.11",
+    "electron-nightly": "^29.0.0-nightly.20231115",
     "electron-to-chromium": "^1.4.212",
     "enquirer": "^2.3.6",
     "esbuild": "^0.18.11",
diff --git a/packages/playwright-core/src/server/electron/electron.ts b/packages/playwright-core/src/server/electron/electron.ts
index eeb27552a..3a4849036 100644
--- a/packages/playwright-core/src/server/electron/electron.ts
+++ b/packages/playwright-core/src/server/electron/electron.ts
@@ -150,7 +150,7 @@ export class Electron extends SdkObject {
         try {
           // By default we fallback to the Electron App executable path.
           // 'electron/index.js' resolves to the actual Electron App.
-          command = require('electron/index.js');
+          command = require('electron-nightly/index.js');
         } catch (error: any) {
           if ((error as NodeJS.ErrnoException)?.code === 'MODULE_NOT_FOUND') {
             throw new Error('\n' + wrapInASCIIBox([

[dgozman]

From the bisect range, electron/electron#37535 looks most likely.

[mxschmitt]

Turns out

console.log(process.mainModule)

or

console.log(require.main)

is undefined after this version. And we need this in order get access to the electron object inside our code as per

playwright/packages/playwright-core/src/server/electron/electron.ts

Line 75 in 1b22c43

const source = `process.mainModule.require('electron')`;