Enhancement: Don't refer to "react" for default JSX/TSX RuleTester file name

[JoshuaKGoldberg]

Before You File a Proposal Please Confirm You Have Done The Following...

• I have searched for related issues and found none that match my proposal.
• I have searched the current rule list and found no rules that match my proposal.
• I have read the FAQ and my problem is not listed.

Relevant Package

rule-tester

My proposal is suitable for this project

• I believe my proposal would be useful to the broader TypeScript community (meaning it is not a niche proposal).

Description

Right now, RuleTester defaults to react.tsx when JSX/TSX is enabled:

typescript-eslint/packages/rule-tester/src/RuleTester.ts

Line 71 in 56bf020

defaultFilenames: { ts: 'file.ts', tsx: 'react.tsx' },

...but JSX syntax isn't exclusively used by React! Other libraries such as Astro and Solid use it.

How about we go with ... file.tsx?

Additional Info

💖

[Josh-Cena]

No opinions on using a more neutral name but currently the two files are run in the same program and could interact: #7248 So we should either fix that or choose another name? Not sure what the impacts may be

[bradzacher]

Statistically it's the use case a plugin is testing for (eg astro is 1% the size of react).

I'm not specifically against changing it - but I think it's bikeshedding and not worth the churn for end users.

[JoshuaKGoldberg]

After thinking about this for a while, I'm more dead-set that we should change this 😅. Even with React taking up something like 99% of npm downloads for JSX packages. "react" refers to a specific userland library and not part of the TS language the way "jsx" does. I really think we should not hardcode a userland library name in the test infrastructure we provide to people.

Take https://github.com/solidjs-community/eslint-plugin-solid as an example. It uses us: https://github.com/solidjs-community/eslint-plugin-solid/blob/90746131608c4aeb33ae8542731fbbbf0dba9e54/test/ruleTester.ts. It's really awkward IMO that the internal file name for SolidJS JSX test files is react.tsx. 😬

As noted, I think this is blocked on #7248 anyway. My proposal would be to have them default to file.ts & file.tsx once #7428 is resolved and doing so wouldn't introduce cross-test weirdness.

[bradzacher]

Take https://github.com/solidjs-community/eslint-plugin-solid as an example. It uses us: https://github.com/solidjs-community/eslint-plugin-solid/blob/90746131608c4aeb33ae8542731fbbbf0dba9e54/test/ruleTester.ts. It's really awkward IMO that the internal file name for SolidJS JSX test files is react.tsx. 😬

It's always been freely possible to change the filename. So them not changing the config is really either them not knowing they can change it or them choosing not to.

typescript-eslint/packages/rule-tester/src/types/RuleTesterConfig.ts

Lines 13 to 16 in e8653ec

	readonly defaultFilenames?: Readonly<{
	ts: string;
	tsx: string;
	}>;

They could do this and globally change the filename:

RuleTester.setDefaultConfig({
  defaultFileNames: {
    ts: 'file.ts',
    tsx: 'solid.tsx', 
  },
});