Autogenerate configs from rule files

[nickserv]

See extended discussion in #182

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[nickserv]

Is this something you'd still like help with?

[Belco90]

Hey @nickmccurdy! Yes, for sure. I'll go back to this definitely when couple of extra rules are released. Anyway I had a couple of ideas around this, so I'll try to put them here later to see what we can do. Thanks!

[MichaelDeBoey]

I've been playing around with this idea too lately.

My idea was to add some sort of supportedTestingFrameworks key in the meta docs that's an array of strings and that's been read in order to know if it's in a certain config (for that specific testing framework).

[Belco90]

Oh sorry, I didn't realized it was closed by stale-bot!

My idea was to add some sort of supportedTestingFrameworks key in the meta docs that's an array of strings and that's been read in order to know if it's in a certain config (for that specific testing framework).

Yes, this is one of the things I had in mind, but we don't need to add an extra key for it: we can reuse recommended from rule meta.docs. We can reuse few things from meta.docs actually, and extend it so we have something like:

const ruleConfig = {
  meta: {
    docs: {
      description: string, // existing - small description of the rule --> used for rule doc md file + README rules table
      category: 'Possible Errors' | 'Best Practices' | 'Style Guidelines', // reused - categories for our plugin rather than ESLint categories --> used for rule doc md file
      recommended: string[], // reused - list of framework presets where this rule is enabled rather than ESLint recommended or not --> used for rule doc md file + README rules table
      onlyFor: string[] // new - frameworks this rule applies exclusively --> used for rule doc md file
    },
  },
};

When "rule doc md file" means a new small table at the top of each rule doc file for indicating category, recommended presets, and if it's exclusive for some frameworks.

What do you think?

[MichaelDeBoey]

I would keep recommended as it's intended to use: to mark it as error, warn or off.
That way we can have ruleA warn and ruleB error in our configs if we ever want to do this in the future.

For category, I would keep them all as 'Best Practices' as a lot of other ESLint plugins are keeping the ESLint categories too and don't reuse them in the context of their own plugin.

I like the idea of having the distinction of saying "this framework supports it" and "we should include it in the config for this framework", but I'm not sure about the naming.

So what I would propose to do is:

const ruleConfig = {
  meta: {
    docs: {
      // existing
      description: string,
       // existing
      category: 'Possible Errors' | 'Best Practices' | 'Style Guidelines',
      // existing
      recommended: string,
      // list of frameworks that are supported by this rule, like your `onlyFor` so we explicitly say what frameworks are supported
      supportedTestingFrameworks: ('dom' | 'angular' | 'react' | 'vue')[],
      // list of framework configs this rule is included
      recommendedFor: ('dom' | 'angular' | 'react' | 'vue')[],
    },
  },
};

Showing the supported frameworks and what config the rule is included in in the docs MD of the rule sounds like a great idea too.

[Belco90]

I'm confused about recommended key now. In types coming from @typescript-eslint/experimental-utils is indicated as false | "warning" | "error" but in ESLint docs is indicated as boolean.

Anyway, both ways are meant to indicate if the rule has to be included in the recommended preset or not. We don't have such a preset though, but a list of recommended ones per framework, so having meta.docs.recommended as a single value means nothing for us. Instead, we can rewrite it as a list or even better as an object where keys are Shareable Config names and values are false | "warning" | "error" to match the types you mentioned, which are mode detailed.

With this idea we wouldn't need recommendedFor but reuse recommended. Everything else would be the same form your last suggestion.

For category, I would keep them all as 'Best Practices' as a lot of other ESLint plugins are keeping the ESLint categories too and don't reuse them in the context of their own plugin.

That's the point of my suggestion: since we are not interested in default ESLint categories, we override it with our own ('Possible Errors' | 'Best Practices' | 'Style Guidelines' which is different from ESLint categories), so we use it to indicate the category at the top of each rule doc. This would help users to know how subjective/objective the rules are and to which area they apply.

[MichaelDeBoey]

Instead, we can rewrite it as a list or even better as an object where keys are Shareable Config names and values are false | "warning" | "error" to match the types you mentioned, which are mode detailed.

With this idea we wouldn't need recommendedFor but reuse recommended.

That's indeed even a better idea 👍, since we can then have

• 1 less key
• different recommended settings for each testing framework

That's the point of my suggestion: since we are not interested in default ESLint categories, we override it with our own ('Possible Errors' | 'Best Practices' | 'Style Guidelines' which is different from ESLint categories), so we use it to indicate the category at the top of each rule doc. This would help users to know how subjective/objective the rules are and to which area they apply.

I'm not 100% convinced about this one tbh.
We could do this in a separate PR though if the team decides this is a better way.

[Belco90]

We can debate about the categories themselves for sure! Another idea I had for that was just defining categories as priorities level as in Common mistakes with React Testing Library post, so we would have category: "low" | "medium" | "high" which would be reflected on each rule doc file.

Anyway, this was just an idea to use category for something useful (as it's not used at all at the moment), and give to the users some context around area or importance of the rule.

[MichaelDeBoey]

Instead, we can rewrite it as a list or even better as an object where keys are Shareable Config names and values are false | "warning" | "error" to match the types you mentioned, which are mode detailed.

With this idea we wouldn't need recommendedFor but reuse recommended.

Thinking about this a bit more: we could even keep it as it is and make it recommended for all frameworks (with the specified value) if it's not an object.