Oxfmt

Oxfmt

Use this skill when work touches Oxfmt or Oxc formatting: install/config, day-to-day usage, Prettier/Biome migration, sorting extras, language support, editors, or CI --check gates.

Workflow

1. Inspect the local Oxfmt surface before changing code:
   • Package version for oxfmt (still 0.x / beta until 1.0).
   • Config: prefer oxfmt.config.ts / .mts with defineConfig; also accept .oxfmtrc.json(c) (one type per directory); Vite+ may use fmt in vite.config.ts instead.
   • Remaining Prettier/Biome setup, .prettierignore, scripts (fmt / fmt:check), editor default formatter.
2. For setup, how-to, style choices, sorting, monorepos, pairing with Oxlint, or troubleshooting, follow the full guide first: usage-guide.md.
3. Refresh current official docs when versions differ from the snapshot or the work touches language support, sorting, or migration. Start from source-map.md.
4. Route deeper detail to the focused references:
   • Install, CLI, config options, editorconfig: setup-cli-config.md.
   • Languages, sorting (including Tailwind sortTailwindcss), ignores, inline comments: languages-sorting-ignores.md.
   • Prettier/Biome migration, coexistence, CI, and .vscode settings (format / sort imports / remove unused): prettier-migration-ci.md.
5. Preserve the project's print width and quote/semi style unless migrating or the user asks to change them.
6. Verify with bunx oxfmt --check (CI) or bunx oxfmt (write) on the touched paths.

Core Judgment

• Oxfmt is Prettier-compatible for JS/TS (aim: match Prettier output; diffs vs recent Prettier are bugs). It is not 1.0 yet — pin lockfiles.
• Default mode is write. CI gate is oxfmt --check (exit 1 on drift).
• No Prettier-style CLI style flags (--no-semi, etc.) — style lives in the config file only.
• Default printWidth is 100, not Prettier's 80. Set printWidth: 80 when migrating to minimize diffs.
• Prefer oxfmt.config.ts + defineConfig for new configs. Keep or use .oxfmtrc.json only when the project already has it. --init / --migrate may still write JSON — convert to TS when adding a new config.
• Prefer ignorePatterns for new projects; .prettierignore still works during migration.
• Built-in sorting (sortImports, sortTailwindcss, sortPackageJson, jsdoc) replaces Prettier plugins — Prettier plugins are unsupported.
• Tailwind: enable sortTailwindcss; set stylesheet (v4) or config (v3); list helpers in functions (cn/clsx/…). Paths are relative to the Oxfmt config.
• sortPackageJson defaults on — expect package.json diffs; disable if unwanted.
• Editor: Oxfmt owns format + import/Tailwind sort on save; Oxlint owns unused removal via source.fixAll.oxc. Disable TS organizeImports / removeUnusedImports to avoid fighting Oxc.
• Do not run Oxfmt alongside Prettier or Biome as formatters in the same pipeline.
• Oxfmt formats; it does not replace a linter. Drop eslint-plugin-prettier; keep eslint-config-prettier only if ESLint remains.
• Astro and formats that need Prettier plugins may be blockers until Oxfmt supports them.

Verification

Prefer repository-owned commands. For meaningful Oxfmt work, cover the relevant subset:

• bunx oxfmt --check on changed paths or the whole repo for CI parity.
• bunx oxfmt locally / lint-staged when applying format.
• After Prettier migration: spot-check JS/TS diffs; confirm printWidth intent; remove Prettier scripts/deps when ready.
• Sorting: confirm sortImports / Tailwind (stylesheet or config + functions) / package.json behavior matches team expectations.
• Editor format-on-save + source.fixAll.oxc smoke when changing the Oxc extension settings; confirm TS organize-imports is off.

Report which checks ran, which did not, and any 0.x maturity or language-support assumptions that remain.