[web-test-runner] Browser Launcher for Electron

[trusktr]

It would be great to have an Electron runner. Useful for testing web apps that also access Node.js APIs.

[Westbrook]

Would that be something you were interested in contributing on maintaining in a parallel project?

[trusktr]

Looks like Playwright has experimental support for automating Electron!

https://playwright.dev/docs/api/class-electron

This will be the easy way to add Electron support!

[Westbrook]

If that’s so, and it fits within the current API structure, we’d be happy to accept a PR to add support for this!

[trusktr]

Looking at the code, it looks like for the most part we just need to update the product list,

web/packages/test-runner-playwright/src/PlaywrightLauncher.ts

Line 9 in aadcbea

export type ProductType = 'chromium' | 'firefox' | 'webkit';

web/packages/test-runner-playwright/src/index.ts

Line 10 in aadcbea

const validProductTypes: ProductType[] = ['chromium', 'firefox', 'webkit'];

with one caveat: the electron launcher is under playwrite._electron with an underscore (for "experimental" I'm guessing), so we'd need to make the product list handle the underscored string, but otherwise looks like calling it has the same API so it'll just fit in. For example this would be accessing the playwright._electron API:

web/packages/test-runner-playwright/src/PlaywrightLauncher.ts

Line 90 in aadcbea

this.debugBrowser = await playwright[this.product].launch({

web/packages/test-runner-playwright/src/PlaywrightLauncher.ts

Line 143 in aadcbea

const browser = await playwright[this.product].launch(this.launchOptions);

Because Electron is Chromium-based, it might support devtools, so we could try updating this line too:

https://github.com/modernweb-dev/web/blob/aadcbea59e3cf929cc0ab41775b66f866d5a9dcc/packages/test-runner-playwright/src/PlaywrightLauncher.ts#L93C9-L93C47

[trusktr]

Alright, here's a starting point:

• first step to get electron browser running, but tests not working yet #2818

It manages to run the Electron window non-headlessly, but then it seems to not run any tests.

It might have to do with the context and page creation, which is different than with other browsers.

I'm not sure yet how to make it work. I left a message in Playwright Discord for advice on the context handling.