[Feature]: Lint Rstest support

[elecmonkey]

What problem does this feature solve?

Related discussion: web-infra-dev/rstest#85 (comment)

Most of the rules for jest may also be applicable to Rstest. In a typical repo which using Rstest - web-infra-dev/rsbuild - around 2/3 of the eslint-plugin-jest rules can pass directly.

So I have a proposal: we could share an abstraction layer under both Jest and Rstest lint rules in our repo. Consider Rslint is now porting rules from eslint-plugin-jest actively, we can extract some utils outside first. once the jest rules become stable, we can start building Rstest rules on top of the existing things.

Tracker

Jest Recommended (13/13)

Rule Name	Will implement	Status	Level
expect-expect	✅	Merged #1614	warn
no-alias-methods	✅	Merged #1837	Not recommended1
no-conditional-expect	✅	Merged #1548	error
no-deprecated-functions	🚫	🚫	🚫
no-commented-out-tests	✅	Merged #1339	warn
no-disabled-tests	✅	Merged #1475	warn
no-done-callback	🚫	🚫	🚫
no-export	🚫	🚫	🚫
no-focused-tests	✅	Merged #1363	error
no-identical-title	✅	Merged #1473	error
no-interpolation-in-snapshots	✅	Merged #1604	error
no-jasmine-globals	🚫	🚫	🚫
no-mocks-import	✅	Merged #1295	error
no-standalone-expect	✅	Merged #1701	error
no-test-prefixes	🚫	🚫	🚫
valid-describe-callback	🚫	🚫	🚫
valid-expect	✅	Merged #1695	error
valid-expect-in-promise	✅	Merged #1696	error
valid-title	✅	Merged #1606	error

Vitest Recommended not in Jest Recommended (3/3)

Rule Name	Will implement	Status	Level
no-import-node-test	✅	Merged #1775	error
prefer-called-exactly-once-with	✅	Merged #1776	error
require-local-test-context-for-concurrent-snapshots	✅	Merged #1778	error

Jest Not Recommended (6/47)

Rule Name	Ready for Jest	Will implement	Status
consistent-test-it	—	✅	—
max-expects	✅	✅	Merged #1838
max-nested-describe	✅	✅	—
no-conditional-in-test	✅	✅	Merged #1839
no-confusing-set-timeout	✅	🚫	🚫
no-duplicate-hooks	✅	✅	—
no-hooks	✅	✅	Merged #1835
no-large-snapshots	—	✅	—
no-restricted-jest-methods	✅	🚫	🚫
no-restricted-matchers	✅	✅	—
no-test-return-statement	—	✅	—
no-unneeded-async-expect-function	✅	✅	—
no-untyped-mock-factory	—	✅	—
padding-around-after-all-blocks	—	✅	—
padding-around-after-each-blocks	—	✅	—
padding-around-all	—	✅	—
padding-around-before-all-blocks	—	✅	—
padding-around-before-each-blocks	—	✅	—
padding-around-describe-blocks	—	✅	—
padding-around-expect-groups	—	✅	—
padding-around-test-blocks	—	✅	—
prefer-to-be	✅	✅	—
prefer-to-contain	✅	✅	—
prefer-to-have-length	✅	✅	—
prefer-called-with	✅	✅	—
prefer-comparison-matcher	✅	✅	—
prefer-each	✅	✅	Merged #1841
prefer-ending-with-an-expect	—	✅	—
prefer-equality-matcher	✅	✅	—
prefer-expect-assertions	—	✅	—
prefer-expect-resolves	✅	✅	—
prefer-hooks-in-order	✅	✅	Merged #1836
prefer-hooks-on-top	✅	✅	—
prefer-importing-jest-globals	—	🚫	🚫
prefer-jest-mocked	✅	🚫	🚫
prefer-lowercase-title	—	✅	—
prefer-mock-promise-shorthand	—	✅	—
prefer-mock-return-shorthand	—	✅	—
prefer-snapshot-hint	—	✅	—
prefer-spy-on	✅	✅	—
prefer-strict-equal	✅	✅	—
prefer-to-have-been-called	✅	✅	—
prefer-to-have-been-called-times	✅	✅	—
prefer-todo	✅	✅	Merged #1840
require-hook	✅	✅	—
require-to-throw-message	✅	✅	—
require-top-level-describe	✅	✅	—
valid-mock-module-path	—	🚫	🚫
no-error-equal	—	✅	—
no-unnecessary-assertion	—	✅	—
unbound-method	—	✅	—
valid-expect-with-promise	—	✅	—

Vitest Not Recommended not in Jest (7/15)

Rule Name	Will implement	Status
consistent-each-for	✅	—
consistent-test-filename	✅	—
consistent-vitest-vi	🚫2	🚫
hoisted-apis-on-top	✅	Merged #1929
no-conditional-tests	✅	PR #1919
no-importing-vitest-globals	🚫2	🚫
no-restricted-vi-methods	🚫2	🚫
prefer-called-once	✅	Merged #1921
prefer-called-times	✅	Merged #1890
prefer-describe-function-title	🚫	🚫
prefer-expect-type-of	✅	Merged #1885
prefer-import-in-mock	✅	Merged #1930
prefer-importing-vitest-globals	🚫2	🚫
prefer-strict-boolean-matchers	✅	—
prefer-to-be-falsy	✅	—
prefer-to-be-object	🚫	🚫
prefer-to-be-truthy	✅	—
prefer-vi-mocked	🚫2	🚫
require-awaited-expect-poll	✅	PR #1920
require-mock-type-parameters	✅	PR #1944
require-test-timeout	✅	Merged #1918
warn-todo	✅	Merged #1889

Rstest-only Rules (0/5)

Rule Name	Will implement	Status
consistent-rstest-namespace	✅	PR #1942
no-importing-rstest-globals	✅	—
no-restricted-rstest-methods	✅	—
prefer-importing-rstest-globals	✅	—
prefer-rs-mocked	✅	—

Footnotes

1. Jest deprecated these aliases in Jest 26 and removed them in Jest 30. Vitest still supports them and keeps no-alias-methods outside its recommended config, so canonical naming is primarily an opt-in style preference there. Rstest follows Vitest because its expect implementation is based on @vitest/expect. ↩

2. These rules are all defined in terms of the vi object or the vitest module specifier, neither of which exists in Rstest — the equivalent utilities are exported as rstest / rs and are also reachable through import.meta.rstest. So they cannot be ported under the same name. Where the underlying idea still applies, it belongs to a separately named Rstest rule (for example no-restricted-rstest-methods, prefer-rs-mocked), not to a port of the Vitest rule. ↩ ↩² ↩³ ↩⁴ ↩⁵

[eryue0220]

I think this proposal is great and feasible, but the first step is what kind of rules is rstest need then we can move the common rules to the shared or some directory that can share.

As for the API design I'm not sure it's need to add a new abstract parser layer for jest and rstest, according to the oxc codebase for jest and vitest, ParseJestFnCall is enough. But I'm not very familiar with rstest, and this is just my initial thought.

[elecmonkey]

I think we could move this discussion forward as the port of jest/* recommended rules is nearing completion. A possible way is to create a testfw (or another name) dir under internal/plugin to impl common testing-rule capabilities. This shared layer would handle the rule core, AST traversal, diagnostic generation, fix logic, and common call structures. internal/plugin/jest and new internal/plugin/rstest call this shared layer through their own wrappers. Each wrapper would provide profile-specific information such as the rule name, test API parser, parameterized call forms, allowed syntax differences, and diagnostic messages. I’d like to hear whether the maintainers (cc @fansenze @swwind ) and the community see any concerns with this direction.

Before seeking more advice (may we'd better consider impl details after rule-options-schema refactor finished?), I’ll spend the coming days analyzing the necessity and compatibility of each existing jest/* rule on the Rstest side. I think we could use this issue as the tracker (new section above).

[fansenze]

I think it makes sense to add a new internal/plugins/rstest directory to host the rstest rules.

As for shared utilities, the current convention is roughly:

• rule-scope utilities usually live under internal/plugins/*/utils
• utilities shared across rules usually live under internal/utils

If most of the rule logic can be reused almost as-is, I think it would even be reasonable for rules under internal/plugins/rstest to directly reference the existing rules in internal/plugins/jest. In that case, the main thing would be to make sure the tests under rstest/*/*_test.go correctly cover and validate the corresponding rstest cases.