feature request: ava configs' factory function promise support.

[iamstarkov]

Description

The config file must have a default export, using ES modules. It can either be a plain object or a factory function which returns a plain object.

vs

We highly recommend the use of async functions. They make asynchronous code concise and readable, and they implicitly return a promise so you don't have to.

I propose to add support for a promise from a factory function, because in my case i need to look around the environment I am going to run tests for and read some files. I can use synchronous versions of fs module, but it is contrary to node's guidelines and Ava's spirit.

Test Source

export default async ({ projectDir }) => {
  /* await stuff */
  return { /* … */};
}

Error Message & Stack Trace

☯ yarn test
yarn run v1.9.4
$ ./bin test

✖ Factory method exported by ava.config.js must not return a promise

Config

N/A, see above.

Command-Line Arguments

N/A

Relevant Links

• Sorry, project is not public

Environment

Node.js v8.11.4
darwin 17.7.0
npm 5.6.0
yarn 1.9.4
ava 1.0.0-beta.8

[novemberborn]

Yup, we can do that. The restriction was added to reduce the complexity of adding this feature in the first place.

We'll have to make lib/cli work asynchronously:

ava/lib/cli.js

Line 24 in bfe1630

conf = loadConf();

We'll also need to figure out how to make this work in our ESLint plugin:

https://github.com/avajs/eslint-plugin-ava/blob/6bb239fe1cd97fd671318253debc153fab7db071/util.js#L47

[iamstarkov]

sounds good

[a-deeb]

Hi, can help out and continue where things were left off, I just made a PR #2076

[novemberborn]

@a-deeb thanks, I'll have a look. If you've got questions about GitHub please comment on your PR here: #2076 there's no need to close it and open a new one.

[a-deeb]

Thanks @novemberborn , if i have any questions ill ask here, and ill do my best to add this feature.

[a-deeb]

Sorry for opening and closing the PR I had opened before , I did too many commits on it , the changes i made kept failing the tests, to go back to previous version or to the original is the command git checkout -f or git reset --hard or git-revert ,Also I am trying to continue where @MiguelSolano left off

[novemberborn]

@a-deeb don't worry about the commit history, we can fix that when we land the PR. There's many different ways of going back to a previous version. Perhaps give GitHub Desktop a try. They've got a post on it here: https://help.github.com/en/desktop/contributing-to-projects/reverting-a-commit

This post has some good information on pushing changes: https://www.atlassian.com/git/tutorials/syncing/git-push

I can't review your code if you keep closing the PR. Just leave #2077 open and let me know when you'd like me to take a look at it.

[a-deeb]

Thanks again @novemberborn !

[novemberborn]

Our ESLint plugin now relies on AVA's config, and the ESLint plugin must be synchronous. I'm not sure where that leaves us with supporting asynchronous factories.

[iamstarkov]

we still can support async config factories, but eslint plugin can be turned into synchronous with setTimeout or something

[novemberborn]

we still can support async config factories, but eslint plugin can be turned into synchronous with setTimeout or something

You can't go from asynchronous to synchronous.

[iamstarkov]

true, sorry, I had a brain fart

[iamstarkov]

I'll close it then

[novemberborn]

No I'd still like to support this. But we need to figure out the impact on our ESLint plugin. Maybe ESLint will support asynchronous plugins. Maybe, as long config-reliant rules are opt-in, we can make them fail when the config is asynchronous.

[novemberborn]

This will be available in AVA 4.