@rsvelte/oxlint-plugin

Run rsvelte's Svelte diagnostics as oxlint rules. Add one line to your .oxlintrc.json and oxlint's JS/TS rules and rsvelte's Svelte rules — the native eslint-plugin-svelte rule ports plus the Svelte compiler's own validator / accessibility warnings — land in a single pass and a single report.

The engine is native-first with a wasm fallback: on a supported platform the plugin loads a prebuilt native addon (rsvelte_lint.node, shipped in the per-platform @rsvelte/lint-<triple> packages) for maximum speed, and transparently falls back to the @rsvelte/compiler WebAssembly engine everywhere else. Both produce byte-identical diagnostics, and there is no postinstall step.

⚠️ Early stage (v0), oxlint alpha. oxlint's JS-plugin API and its .svelte support are alpha; see Limitations.

Install

npm install -D @rsvelte/oxlint-plugin oxlint
# pnpm add -D @rsvelte/oxlint-plugin oxlint

Requires oxlint ≥ 1.64 (the first release with the JS-plugin API).

Usage

Enable the plugin and turn on rsvelte's recommended rule set in your .oxlintrc.json:

{
  "jsPlugins": ["@rsvelte/oxlint-plugin"],
  "extends": ["./node_modules/@rsvelte/oxlint-plugin/recommended.json"]
}

Then run oxlint as usual:

npx oxlint .

Every Svelte diagnostic is reported under the svelte/ namespace, so you can tune any of them alongside oxlint's own rules:

{
  "jsPlugins": ["@rsvelte/oxlint-plugin"],
  "extends": ["./node_modules/@rsvelte/oxlint-plugin/recommended.json"],
  "rules": {
    "svelte/no-at-html-tags": "error",
    "svelte/a11y_missing_attribute": "error",
    "svelte/require-each-key": "off"
  }
}

You don't have to use recommended.json — you can instead list only the rules you want:

{
  "jsPlugins": ["@rsvelte/oxlint-plugin"],
  "rules": {
    "svelte/no-at-html-tags": "warn",
    "svelte/a11y_click_events_have_key_events": "warn"
  }
}

Rule ids

• Native rules (eslint-plugin-svelte ports) keep their familiar id under the svelte/ prefix, e.g. svelte/no-at-html-tags, svelte/require-each-key.
• Compiler / validator / a11y warnings use the compiler's snake_case code, e.g. svelte/a11y_missing_attribute, svelte/css_unused_selector, svelte/state_referenced_locally.

Severity is owned entirely by your oxlint config: a rule runs only when your config (or the bundled recommended.json) enables it, and "off" / "warn" / "error" are honoured as for any oxlint rule. recommended.json is generated from the live rule catalog, so it never drifts from the engine.

How it works

oxlint's alpha .svelte support extracts and lints the <script> block. This plugin registers one oxlint rule per rsvelte diagnostic id; when oxlint visits a .svelte file's script, the plugin reads the whole component from disk, runs rsvelte's linter over all of it once (markup + script + style, cached per file), and reports each diagnostic under svelte/<id>:

• Diagnostics inside the <script> block are mapped to accurate line/column positions.
• Diagnostics in markup or <style> — which oxlint's .svelte support cannot yet position — are anchored at the top of the <script> block, with their real [line:column] carried in the message.

Engine (native / wasm)

The plugin picks its engine at startup:

1. native — requires rsvelte_lint.node from the matching @rsvelte/lint-<triple> optional dependency (installed automatically for your platform);
2. wasm — falls back to @rsvelte/compiler if the native addon isn't present (unsupported platform, --no-optional, …).

Both engines run the same Rust rule engine and return identical diagnostics. Override the choice with RSVELTE_OXLINT_ENGINE=native|wasm (setting native errors instead of falling back — useful in CI to guarantee the fast path), and set RSVELTE_OXLINT_DEBUG=1 to print the selected engine once to stderr.

Limitations

These follow from the current (alpha) state of oxlint's .svelte support and will lift as it matures:

• Scriptless components are skipped. oxlint does not invoke plugins on a .svelte file that has no <script> block, so this plugin sees nothing for them and reports nothing. A component with any <script> (even an empty one) is linted in full, markup included. To lint an otherwise scriptless component, add an empty <script></script>.
• Markup / style positions are approximate. As described above, such diagnostics point at the top of the <script> block; the true location is in the message text ([line:column] …).
• No autofix. rsvelte's fixes are not yet bridged to oxlint's --fix.

For pixel-accurate markup positions and full scriptless coverage today, use rsvelte-check or the rsvelte VS Code extension directly; this plugin is about folding Svelte diagnostics into an existing oxlint pass.

Sister packages

Part of the rsvelte project — a Rust port of the Svelte compiler:

• @rsvelte/compiler — the compiler / linter engine (wasm)
• @rsvelte/svelte-check — CLI type + diagnostic checker
• @rsvelte/svelte2tsx — Svelte → TSX
• @rsvelte/fmt — the formatter
• @rsvelte/vite-plugin-svelte — the Vite plugin

License

MIT