[Feature]: webserver: add option for custom health check

[jansepke]

🚀 Feature Request

add a new option to the playwright config webServer.healthcheck as an alternative to the existing webServer.url. this new config would be executed as a shell comand and retried until it either exits with exit code 0 or webServer.timeout is over.

the healthcheck could also be a JS function that returns true/false instead of passing a path to a shell script.

Example

export default defineConfig({
  webServer: {
    command: 'npm run start',
    healthcheck: './is-server-ready.sh',
  },
});

Motivation

Sometimes deciding if a webserver is ready for a test is more complex then just calling a healthcheck endpoint and expecting a status code 200. for example when running tests against a dockerized web application in CI we are using some complex data preseeding where the webserver itself does not know when the data is completely preseeded. but we could write a small script that returns if the preseeding is finished.

[jansepke]

I took a look at the code and it should be enough if one would be able to pass isAvailableCallback as an option to the webServer config and then make it used here

playwright/packages/playwright/src/plugins/webServerPlugin.ts

Line 66 in 715123a

this._isAvailableCallback = this._options.url ? getIsAvailableFunction(this._options.url, this._checkPortOnly, !!this._options.ignoreHTTPSErrors, this._reporter.onStdErr?.bind(this._reporter)) : undefined;

[Skn0tt]

Hi Jan! Have you tried embedding your healthcheck in the command script? Copilot told me that something like npm run start && while ! ./is-server-ready.sh; do sleep 1 done should work.

[jansepke]

This will not work as the start command does not exist so the second part of the && never gets executed

[Skn0tt]

Of course, you're right. I've marked this as P3 to collect feedback on how big the need for this feature is amongst the userbase. If you read this, please upvote the issue if you'd like us to ship it.

[jansepke]

would you also accept a PR to make the _isAvailableCallback available through the config without waiting for enough upvotes?

[Skn0tt]

We're careful about extending our public API, so we always take community need into account. So let's wait for upvotes first. I'm sure you can find a workaround for your needs, feel free to post that for anybody else coming across this issue.