refactor: Migrate from ESLint to oxlint and biome #40731

zharinov · 2026-01-27T15:31:40Z

Changes

Replaces ESLint with faster native linters:

oxlint - Rust-based linter for JS/TS rules
biome - Linter + import organizer

Removed (~10 packages)

eslint and all plugins (@typescript-eslint/*, eslint-plugin-import-x, eslint-plugin-promise, @vitest/eslint-plugin, @containerbase/eslint-plugin)
eslint.config.mjs

Added

.oxlintrc.json with comprehensive rule configuration
Custom JS plugin for no-tools-import and test-root-describe rules
biome.json for noUndeclaredDependencies, useNamingConvention, useConsistentObjectDefinitions, and organizeImports
CI step to check for uncommitted changes after biome fixes
Pre-commit hook runs biome to organize imports

Scripts

oxlint / oxlint-fix / oxlint-ci - oxlint commands
biome / biome-fix / biome-ci - biome commands

Context

This doesn't close an Issue, but I accept the risk that this PR may be closed if maintainers disagree with its opening or implementation

AI assistance disclosure

Yes — substantive assistance

Documentation (please check one with an [x])

I have updated the documentation, or

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Code inspection only, or

jamietanna · 2026-01-27T17:24:19Z

Oof just a few changes 😅

I'm gonna say let's hold off until after v43 (unless we need it for the ESM migration)?

zharinov · 2026-01-27T17:24:21Z

Hey, I haven't done double-check yet, but feel free to comment anyways

zharinov · 2026-01-27T17:26:49Z

I'm gonna say let's hold off until after v43 (unless we need it for the ESM migration)?

Don't think we need for ESM.
We have time to think what we need from the new linters.
I think it's not necessarily the 1-to-1 migration, but a chance to review the checks we want.

viceice · 2026-01-27T17:58:22Z

docs/usage/assets/css/style.css

@@ -1,10 +1,10 @@
 .md-header .md-header__button.md-logo {
-  padding: 0;
+	padding: 0;


why this change, looks wrong to me

viceice · 2026-01-27T18:00:09Z

lib/expose.cjs

 */
 function re2() {
-  return require('re2');
+	return require("re2");


no indention change and single quote usage!

viceice · 2026-01-27T18:00:47Z

lib/instrumentation/utils.ts

+  if (typeof e === 'string') {
+    return e;
+  }
+  return JSON.stringify(e);


should be done separately

viceice · 2026-01-27T18:01:37Z

lib/logger/utils.ts

-    ...err,
-  };
+  const response: Record<string, unknown> = {};
+  for (const key of Object.keys(err)) {


separate PR

RahulGautamSingh · 2026-01-27T19:51:51Z

lib/config/options/index.spec.ts

why are these changes necessary?

This file violates "no conditionals in tests", I just asked to reorganize it somehow.

- Restore vi.unmock for mutex in race condition tests - Use early exit pattern in docker versioning isCompatible

viceice

quotes are wrongly changed from single to double 😕

viceice · 2026-01-28T15:58:12Z

lib/config/validation.spec.ts

@@ -1,9 +1,9 @@
 import type { HostRule } from '../types/index.ts';


needs fix 😁

viceice · 2026-01-28T16:00:01Z

tools/lint/rules.js

we should extract a package from it, like i've done for the eslint rules 😁

viceice · 2026-01-28T16:01:25Z

.oxlintrc.json

+  "jsPlugins": ["./tools/lint/rules.js"],
  "categories": {},
  "rules": {
+    "constructor-super": "error",


isn't there some preset support? so we don't need to configure them all manually 🤔

marklai1998 · 2026-01-29T03:47:30Z

@zharinov
biome also come with decent ts+js rules, any reason dual wielding oxlint and biome?

zharinov · 2026-01-29T13:22:23Z

biome also come with decent ts+js rules, any reason dual wielding oxlint and biome?

@marklai1998 We don't need just decent set of rules, we want to supersede all the existing eslint rules. If there is at least one rule covered by biome and not covered by oxlint, it's worth to have both. And we have such rule: it's noParameterProperties, which helps us to make sure Renovate could be run with Node without transpiling, or in the Bun runtime.

Another benefit is imports ordering which seems to be more stable with biome at the moment. I could be wrong on this one, though.

Anyways, compared to the eslint overhead, the 10 seconds to run another tool is nothing. This decision should be revised in the future as oxlint matures, but the current focus is having decent modern tooling which does everything eslint does, without requiring 8Gb memory and 3–5 minutes to finish.

zharinov force-pushed the refactor/eslint-to-oxlint-biome branch 4 times, most recently from 9695b13 to fc89dac Compare January 27, 2026 17:10

zharinov closed this Jan 27, 2026

zharinov force-pushed the refactor/eslint-to-oxlint-biome branch from fc89dac to 13533f7 Compare January 27, 2026 17:18

zharinov reopened this Jan 27, 2026

zharinov requested review from RahulGautamSingh, jamietanna and viceice January 27, 2026 17:23

viceice reviewed Jan 27, 2026

View reviewed changes

RahulGautamSingh reviewed Jan 27, 2026

View reviewed changes

zharinov added 3 commits January 28, 2026 11:59

base

42c7d87

refactor: Migrate from ESLint to oxlint and biome

dc25058

fix: Test fixes for CI

4df1296

- Restore vi.unmock for mutex in race condition tests - Use early exit pattern in docker versioning isCompatible

zharinov force-pushed the refactor/eslint-to-oxlint-biome branch from 13533f7 to 4df1296 Compare January 28, 2026 15:12

viceice reviewed Jan 28, 2026

View reviewed changes

		@@ -1,9 +1,9 @@
		import type { HostRule } from '../types/index.ts';

refactor: Migrate from ESLint to oxlint and biome #40731

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refactor: Migrate from ESLint to oxlint and biome #40731

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zharinov commented Jan 27, 2026

Changes

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AI assistance disclosure

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How I've tested my work (please select one)

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jamietanna commented Jan 27, 2026

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marklai1998 commented Jan 29, 2026

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