test(linter/plugins): add `eslint-stylistic` to conformance tests by overlookmotel · Pull Request #18554 · oxc-project/oxc

overlookmotel · 2026-01-25T20:29:12Z

Add eslint-plugin-stylistic to conformance tests.

99.96% pass rate. The remaining 7 failing tests are not easily fixable:

`jsx-props-no-multi-spaces` rule

1 failing test

The rule clones nodes with Object.assign({}, node), and then uses the loc property of the cloned node. Because loc is a getter on prototype of AST nodes, loc property is not present on the cloned node.

This bug may have real-world impact. We'll need to make loc a real property of node objects to fix it (#10307). We originally had loc getter on the node objects themselves, but that caused a 3x slowdown.

`jsx-tag-spacing` rule

6 failing tests

TypeScript parser (which we use for generating tokens) cannot parse closing JSX tags with whitespace before the / - e.g. <App>text< /App>.

TS-ESLint parser also fails to parse this (AST explorer) so this bug is unlikely to have real-world impact.

overlookmotel · 2026-01-25T20:29:29Z

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Pull request overview

This PR adds eslint-plugin-stylistic to the conformance tests, validating Oxlint's compatibility with this plugin's 129 rules. The tests achieve an impressive 99.96% pass rate (18,303 passing out of 18,310 tests, excluding skipped tests). The 7 failing tests are documented with clear explanations of the root causes.

Changes:

Added dependencies for @typescript-eslint/parser and eslint-vitest-rule-tester to support stylistic plugin testing
Extended RuleTester to handle stylistic plugin's test format, including support for missing errors property via __unknown__ marker
Created stylistic test group configuration with appropriate test transformations, parser handling, and skip conditions
Added initialization script for cloning and setting up the stylistic plugin submodule with necessary patches

Reviewed changes

Copilot reviewed 8 out of 9 changed files in this pull request and generated 6 comments.

Show a summary per file

File	Description
pnpm-lock.yaml	Added `@typescript-eslint/parser`, `eslint-vitest-rule-tester`, and their dependencies to support stylistic plugin testing
apps/oxlint/package.json	Added `@typescript-eslint/parser` and `eslint-vitest-rule-tester` as dev dependencies
apps/oxlint/src-js/package/rule_tester.ts	Exported `ParserOptionsInternal` interface and added handling for `__unknown__` errors marker used when test cases don't specify expected errors
apps/oxlint/conformance/tester.ts	Updated debug script to test stylistic plugin rules with TypeScript/ESLint parser integration
apps/oxlint/conformance/src/rule_tester.ts	Exported `LanguageOptions` and `ParserOptions` types needed by stylistic test group
apps/oxlint/conformance/src/groups/stylistic.ts	Created comprehensive test group for stylistic plugin with custom rule runner mock, parser handling, and skip conditions for known issues
apps/oxlint/conformance/src/groups/index.ts	Registered stylistic test group alongside existing groups
apps/oxlint/conformance/snapshots/stylistic.md	Documented conformance test results showing 99.96% pass rate with detailed failure analysis
apps/oxlint/conformance/init.sh	Added setup script for cloning stylistic plugin, installing dependencies, patching package.json for Node.js imports, and replacing top-level await imports

Files not reviewed (1)

pnpm-lock.yaml: Language not supported

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apps/oxlint/conformance/init.sh

apps/oxlint/conformance/src/groups/stylistic.ts

apps/oxlint/src-js/package/rule_tester.ts

apps/oxlint/conformance/tester.ts

overlookmotel · 2026-01-25T21:30:55Z

Merge activity

Jan 25, 9:30 PM UTC: The merge label '0-merge' was detected. This PR will be added to the Graphite merge queue once it meets the requirements.
Jan 25, 9:31 PM UTC: overlookmotel added this pull request to the Graphite merge queue.
Jan 25, 9:40 PM UTC: The Graphite merge queue removed this pull request due to downstack failures on PR #18552.
Jan 25, 9:40 PM UTC: The Graphite merge queue removed this pull request due to downstack failures on PR #18552.
Jan 25, 10:14 PM UTC: The merge label '0-merge' was detected. This PR will be added to the Graphite merge queue once it meets the requirements.
Jan 25, 10:18 PM UTC: overlookmotel added this pull request to the Graphite merge queue.
Jan 25, 10:19 PM UTC: Merged by the Graphite merge queue.

…8554) Add `eslint-plugin-stylistic` to conformance tests. 99.96% pass rate. The remaining 7 failing tests are not easily fixable: #### `jsx-props-no-multi-spaces` rule 1 failing test The rule clones nodes with `Object.assign({}, node)`, and then uses the `loc` property of the cloned node. Because `loc` is a getter on *prototype* of AST nodes, `loc` property is not present on the cloned node. This bug may have real-world impact. We'll need to make `loc` a real property of node objects to fix it (#10307). We originally had `loc` getter on the node objects themselves, but that caused a 3x slowdown. #### `jsx-tag-spacing` rule 6 failing tests TypeScript parser (which we use for generating tokens) cannot parse closing JSX tags with whitespace before the `/` - e.g. `<App>text< /App>`. TS-ESLint parser also fails to parse this [AST explorer](https://ast-explorer.dev/#eNpFyzEKwzAMBdCrGM0p3UModOkROnkRRgUH1xaWUlqC716pHbJJ7/+/Q4EZVnyhpJ5ZYQI20A/TH04kJVf3ZL5cmS+P1pZw9su0me6xhhCB0hPv1CW3GmE2KKgkGmE68huhbp3EC7+ZB6u8/de+kdOIdcD4AgUpMYU=), so this bug is unlikely to have real-world impact.

github-actions bot added A-linter Area - Linter A-cli Area - CLI A-linter-plugins Area - Linter JS plugins C-test Category - Testing. Code is missing test cases, or a PR is adding them labels Jan 25, 2026

overlookmotel mentioned this pull request Jan 25, 2026

test(linter/plugins): conformance tester set default export on parser modules #18553

Merged

overlookmotel marked this pull request as ready for review January 25, 2026 20:46

overlookmotel requested a review from camc314 as a code owner January 25, 2026 20:46

Copilot AI review requested due to automatic review settings January 25, 2026 20:46

Copilot started reviewing on behalf of overlookmotel January 25, 2026 20:46 View session

Copilot AI reviewed Jan 25, 2026

View reviewed changes

overlookmotel self-assigned this Jan 25, 2026

overlookmotel force-pushed the om/01-24-test_linter_plugins_add_eslint-stylistic_to_conformance_tests branch from 8e1e684 to a356696 Compare January 25, 2026 21:11

overlookmotel force-pushed the om/01-25-test_linter_plugins_conformance_tester_set_default_export_on_parser_modules branch from ca2d841 to e07c667 Compare January 25, 2026 21:11

overlookmotel added the 0-merge Merge with Graphite Merge Queue label Jan 25, 2026

graphite-app bot force-pushed the om/01-25-test_linter_plugins_conformance_tester_set_default_export_on_parser_modules branch from e07c667 to da76bc5 Compare January 25, 2026 21:33

graphite-app bot force-pushed the om/01-24-test_linter_plugins_add_eslint-stylistic_to_conformance_tests branch from a356696 to c421024 Compare January 25, 2026 21:34

graphite-app bot removed the 0-merge Merge with Graphite Merge Queue label Jan 25, 2026

overlookmotel mentioned this pull request Jan 25, 2026

linter/plugins: JSON serialization of defaultOptions breaks rules using Infinity #18469

Closed

overlookmotel marked this pull request as draft January 25, 2026 22:09

overlookmotel force-pushed the om/01-24-test_linter_plugins_add_eslint-stylistic_to_conformance_tests branch from c421024 to 43eccaa Compare January 25, 2026 22:12

overlookmotel marked this pull request as ready for review January 25, 2026 22:12

overlookmotel added the 0-merge Merge with Graphite Merge Queue label Jan 25, 2026

Base automatically changed from om/01-25-test_linter_plugins_conformance_tester_set_default_export_on_parser_modules to main January 25, 2026 22:15

graphite-app bot merged commit 43eccaa into main Jan 25, 2026
21 of 22 checks passed

graphite-app bot deleted the om/01-24-test_linter_plugins_add_eslint-stylistic_to_conformance_tests branch January 25, 2026 22:19

graphite-app bot removed the 0-merge Merge with Graphite Merge Queue label Jan 25, 2026

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test(linter/plugins): add `eslint-stylistic` to conformance tests#18554

test(linter/plugins): add `eslint-stylistic` to conformance tests#18554
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jsx-props-no-multi-spaces rule

jsx-tag-spacing rule

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overlookmotel commented Jan 25, 2026 •

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`jsx-props-no-multi-spaces` rule

`jsx-tag-spacing` rule

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