chore: migrate to oxlint by Rich-Harris · Pull Request #17596 · sveltejs/svelte

Rich-Harris · 2026-01-30T14:49:46Z

This isn't ready for prime-time but I figured I'd try and see what would be involved in migrating. After installing oxlint I ran this command to generate the .oxlintrc.json:

npx @oxlint/migrate --with-nursery --js-plugins --type-aware

pnpm oxlint then failed with

Failed to load JS plugin: eslint-plugin-custom

so I installed it, then

Failed to load JS plugin: @stylistic/eslint-plugin

so I installed it, then

Rule 'no_compiler_imports' not found in plugin 'custom'

and at that point I tapped out

changeset-bot · 2026-01-30T14:49:53Z

⚠️ No Changeset found

Latest commit: 6ef7239

Merging this PR will not cause a version bump for any packages. If these changes should not result in a new version, you're good to go. If these changes should result in a version bump, you need to add a changeset.

This PR includes no changesets

When changesets are added to this PR, you'll see the packages that this PR includes changesets for and the associated semver types

Click here to learn what changesets are, and how to add one.

Click here if you're a maintainer who wants to add a changeset to this PR

github-actions · 2026-01-30T14:51:19Z

Playground

pnpm add https://pkg.pr.new/svelte@17596

connorshea · 2026-01-30T23:20:58Z

Oh, yeah @oxlint/migrate can't handle a rule defined inside the eslint.config.js like it is. There's no way for us to really unless we automatically migrate the code into its own file, which would get messy. If that no_compiler_imports rule were moved into its own file before trying the migration, it should work?

svelte-docs-bot · 2026-02-06T19:41:47Z

Preview: https://svelte-dev-git-preview-svelte-17596-svelte.vercel.app/

Rich-Harris · 2026-02-06T19:55:58Z

Thanks for the pointer! Got it working now.

There are a few plugins we use that aren't currently supported:

no-dupe-args
no-octal
no-restricted-properties
prefer-arrow-callback
n/prefer-global/process
n/prefer-node-protocol

I don't think these are reason enough by themselves not to migrate, but worth flagging.

I needed to add one ignore comment that I don't totally understand — Eslint is okay with this...

/^(?:\p{Lu}[$\u200c\u200d\p{ID_Continue}.]*|\p{ID_Start}[$\u200c\u200d\p{ID_Continue}]*(?:\.[$\u200c\u200d\p{ID_Continue}]+)+)$/u

...but Oxlint isn't.

Other than that:

linting is (predictably) much faster now
we can't get remove eslint from our dependency tree yet because it's a peer dependency of various plugins we're currently using

* remove defautls * format * format abc

benmccann · 2026-02-07T00:20:48Z

+		"svelte/system": "error",
+		"svelte/valid-each-key": "error",
+		"svelte/valid-prop-names-in-kit-pages": "error",
+		"unicorn/no-await-in-promise-methods": "off",


These weren't mentioned in the eslint.config.js. Perhaps they don't work in oxlint and that's why they're disabled here? Maybe add a TODO to re-enable them?

benmccann · 2026-02-07T00:22:10Z

+		"no-unreachable": "error",
+		"no-unused-vars": "off",
+		"no-useless-rename": "off",
+		"svelte/comment-directive": "error",


I'm guessing these come from plugin:svelte/recommended? Maybe we could just set that instead?

benmccann · 2026-02-07T16:15:07Z

    "eslint-plugin-lube": "^0.4.3",
    "eslint-plugin-svelte": "^3.11.0",
    "jsdom": "25.0.1",
+    "oxlint": "^1.42.0",


Do we need oxlint-tsgolint? https://oxc.rs/docs/guide/usage/linter/migrate-from-eslint.html#type-aware-typescript-rules

benmccann · 2026-02-07T16:21:21Z

no-dupe-args

It looks like this won't be implemented and is superseded by strict mode: oxc-project/oxc#479

no-octal

It looks like this won't be implemented and is superseded by strict mode: oxc-project/oxc#479

n/prefer-node-protocol

It looks like this won't be implemented and we should switch to unicorn/prefer-node-protocol: oxc-project/oxc#493

benmccann · 2026-02-07T16:30:17Z

It looks like the .oxlintrc.json isn't extending @sveltejs/eslint-config the way ‎eslint.config.js was. We should probably migrate the base config first and then extend from that

The migration tool seems to have made it a bit hard to follow things. I wonder if it might be easier to just start from scratch and manually migrate

connorshea · 2026-02-07T17:58:29Z

I needed to add one ignore comment that I don't totally understand — Eslint is okay with this...
/^(?:\p{Lu}[$\u200c\u200d\p{ID_Continue}.]*|\p{ID_Start}[$\u200c\u200d\p{ID_Continue}]*(?:\.[$\u200c\u200d\p{ID_Continue}]+)+)$/u
...but Oxlint isn't.

This is fixed in main now, will be released on Monday 🫡

benmccann

I'm super eager to migrate, but personally I'm not sure it's time yet

Digging into this there seems to be a few big issues we're hitting:

we can't extend our common config: oxc-project/oxc#15538
the built-in rules don't currently have support for recommended: oxc-project/oxc#12018
plugins don't yet have support for recommended: oxc-project/oxc#14826 (comment)

And while not a blocker for this repo specifically, quite a number of community projects will be blocked by the lack of TypeScript support in .svelte files: oxc-project/oxc#14826 (comment)

I'd personally close the PR and file a tracking issue linking to those issues. I can't wait though 😄

Rich-Harris · 2026-02-09T23:49:05Z

#17665

chore: migrate to oxlint

d211bd4

Rich-Harris added 4 commits February 6, 2026 14:12

WIP

5a23299

WIP

7e62ef0

fix

53ab2aa

prettier

aae34c2

Rich-Harris temporarily deployed to Publish pkg.pr.new (maintainers) February 6, 2026 19:41 — with GitHub Actions Inactive

Rich-Harris added 4 commits February 6, 2026 14:42

unused

21bc29f

unused

7b7c455

update contributing instsructions

6c2aed4

Merge branch 'main' into oxlint

2ba3a12

Rich-Harris temporarily deployed to Publish pkg.pr.new (maintainers) February 6, 2026 19:49 — with GitHub Actions Inactive

Rich-Harris marked this pull request as ready for review February 6, 2026 20:13

benmccann reviewed Feb 6, 2026

View reviewed changes

Comment thread .oxlintrc.json

reducing oxlint config (#17647)

fcb5ae7

* remove defautls * format * format abc

Rich-Harris temporarily deployed to Publish pkg.pr.new (maintainers) February 6, 2026 22:18 — with GitHub Actions Inactive

benmccann reviewed Feb 7, 2026

View reviewed changes

merge main

6ef7239

benmccann temporarily deployed to Publish pkg.pr.new (maintainers) February 7, 2026 16:25 — with GitHub Actions Inactive

benmccann requested changes Feb 7, 2026

View reviewed changes

Rich-Harris mentioned this pull request Feb 9, 2026

migrate repo to oxlint #17665

Open

Rich-Harris closed this Feb 9, 2026

Uh oh!

Uh oh!

Conversation

Rich-Harris commented Jan 30, 2026

Uh oh!

changeset-bot Bot commented Jan 30, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

⚠️ No Changeset found

Uh oh!

github-actions Bot commented Jan 30, 2026

Uh oh!

connorshea commented Jan 30, 2026

Uh oh!

svelte-docs-bot Bot commented Feb 6, 2026

Uh oh!

Rich-Harris commented Feb 6, 2026

Uh oh!

Uh oh!

benmccann Feb 7, 2026

Choose a reason for hiding this comment

Uh oh!

benmccann Feb 7, 2026

Choose a reason for hiding this comment

Uh oh!

benmccann Feb 7, 2026

Choose a reason for hiding this comment

Uh oh!

benmccann commented Feb 7, 2026

Uh oh!

benmccann commented Feb 7, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

connorshea commented Feb 7, 2026

Uh oh!

benmccann left a comment • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Rich-Harris commented Feb 9, 2026

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

4 participants

changeset-bot Bot commented Jan 30, 2026 •

edited

Loading

benmccann commented Feb 7, 2026 •

edited

Loading

benmccann left a comment •

edited

Loading