biome-config-shaunburdick

Shaun Burdick's Biome configuration — the fast, Rust-based companion to eslint-config-shaunburdick.

One biome.json provides linting, formatting, and import organization tuned to the same house style: 4-space indent, 120-char lines, single quotes, semicolons.

Package: biome-config-shaunburdick

Requirements

• Node.js >= 22
• @biomejs/biome >= 2.5 < 3 (peer dependency)

Usage

Install the config and Biome:

npm install --save-dev @biomejs/biome biome-config-shaunburdick

Extend it from your project's biome.json:

{
    "extends": ["biome-config-shaunburdick"]
}

Then run:

npx biome check .        # lint + format + organize imports
npx biome check --write . # autofix everything fixable

Package Setup

To setup linting automatically, we recommend adding these script entries to your package.json:

"lint": "biome check .",
"lint:fix": "npm run lint -- --write",

Then you can add npm run lint to your test script command to run it before any tests

Recommended pairing

This config enables 164 unique rules, ~91 of which correspond to a rule in eslint-config-shaunburdick (measured against biome.jsonc; the rest are Biome-native correctness/security checks with no ESLint counterpart). The rules that do have ESLint counterparts but are not ported (JSDoc, security plugin, promise discipline, llm-core guardrails, the custom shaunburdick/max-inline-disables rule) have no Biome equivalent and require keeping ESLint alongside. The agent skill carries a layer-by-layer breakdown of the port with each rule's resolved threshold.

What's inside

| Layer | Glob | Highlights | | --- | --- | --- | | Base JS | all files | eqeqeq, no-var, prefer-const, complexity budgets (max 5 params, cognitive 15), no magic numbers, no console/alert/eval, import cycle detection | | TypeScript | **/*.{ts,tsx} | strict TS rules ported from typescript-eslint strict: no-floating-promises, no-misused-promises, no-unnecessary-conditions, exhaustive switches, explicit member accessibility, interface definitions | | React | **/*.{js,mjs,cjs,jsx,mjsx,ts,tsx,mtsx} | full a11y suite, hooks deps (warn), button types, iframe sandbox, array index keys, plus the 15 service-worker globals Biome lacks natively |

Formatting is delegated to Biome's formatter (indentStyle: space, indentWidth: 4, lineWidth: 120, single quotes); import ordering runs via the organizeImports assist action.

Known divergences from the ESLint config

1. Magic numbers are stricter — Biome's noMagicNumbers has no ignore-list option; it flags 3–5, 12, 15, 120 (which our llm-core config ignored) and exempts 24/60 (which we flagged).
2. Promise discipline is thinner — only nested promises are checked; always-return, catch-or-return, and param-names stay ESLint-only.
3. No JSDoc, security-plugin, or llm-core coverage — keep ESLint for those.
4. max-inline-disables is impossible in Biome — its GritQL plugin system cannot see comments.
5. 13 rules come from Biome's nursery (unstable API): noImpliedEval, useArraySome, useIncludes, useStringStartsEndsWith, noFloatingPromises, noMisusedPromises, useAwaitThenable, useExhaustiveSwitchCases, useNullishCoalescing, noJsxLeakedDollar, noJsxNamespace, useIframeSandbox, and useReactAsyncServerFunction may move or change options in minor releases. Pin @biomejs/biome accordingly — the >=2.5.0 <3 peer range will not protect you.

Development

npm install
npm test          # validates biome.json + runs smoke tests against fixtures

Smoke tests live in test/ and assert that representative violations actually fire the expected Biome rules, while a compliant fixture passes clean.

Versioning Policy

• Major (new linting errors)
  • A new rule is added
  • An existing rule is made more strict
  • A new plugin is added to an existing config
  • An existing plugin is updated to be more strict
• Minor (same or fewer linting errors)
  • A rule is removed
  • An existing rule is made less strict
  • Adding a new configuration
  • An existing plugin is updated to be less strict
• Patch (non-user-facing changes)
  • Changes to documentation
  • Fixes for build or publication
  • Modifying tests

See CHANGELOG.md for the version history.

Agent Skill

biome-config-shaunburdick is an agent skill covering install, setup, the three layers, the nursery-rule stability risk, and the biome migrate pinning step — so an agent hitting an unfamiliar Biome diagnostic knows what it protects against. It opens with a "when to use which" table pointing at the ESLint skill, since the two configs are alternatives rather than companions.

Publish steps

Publishing is automated: once a version bump lands on main, CI compares package.json against npm and publishes with provenance if the version is new, then creates a biome-vX.Y.Z GitHub release.

• Checkout main (git checkout main)
• Pull main (git pull)
• Examine CHANGELOG.md to determine next version (X.Y.Z)
• Bump version in package.json and merge to main
• CI publishes the new version and cuts the release