Add support for --env-file= flag for node 20 in nodeArguments

[torbjornvatn]

Please provide details about:

• What you're trying to do
  I was hoping that I could add a config like:

"nodeArguments": [
   "--env-file=.env"
],

and get access to the environments loaded by Node from that file.
--env-fileconfig

• Why you can't use AVA for this
  Even though ava accepts the nodeArguments config above the result of running:

console.log(process.execArgv)
console.log(process.version)
console.log(process.env.DB_CONNECTION)

in a test is this:

[ '--env-file=.env', '--enable-source-maps' ]
v20.10.0
undefined

• And maybe how you think AVA could handle this
  Would it be possible to make ava pass this on to node so it gets loaded as environment variables

[novemberborn]

nodeArguments are passed when creating worker threads (default) or child processes.

However with worker threads, not all arguments have an effect. Some values are inherited from the main process. My guess is that this is the case for --env-file.

Running the following should work:

NODE_OPTIONS="--env-file=.env" npx ava

This way, the env vars are added to the main AVA process and should be inherited by the worker threads.

See also nodejs/node#37410.

[torbjornvatn]

Hmm, seems like that's not allowed actually

node: --env-file= is not allowed in NODE_OPTIONS
It's not in this list

I've solved it by falling back to dotenv for now, but hopefully the worker threads will get support for this eventually.

Could it be an alternative to add an envFile config to Ava as a supplement to environmentVariables?

[novemberborn]

A good starting point would be to use dotenv in the ava.config.js and set environmentVariables to the resulting object.