prefer-oxfmt-over-prettier

What it flags

Flags repositories that appear to use Prettier without visible Oxfmt adoption.

The finding is repository-wide: the evidence comes from repository formatting config and package metadata, not from a workflow-local command.

Why it matters

Oxfmt is positioned by OXC as a high-performance, Prettier-compatible formatter for the JavaScript ecosystem, so a direct CI formatting path is often a good migration candidate.

The practical reason this rule recommends Oxfmt is not only raw speed. For simple Prettier paths, Oxfmt is intended to fit existing Prettier-style format / format:check workflows with minimal script, CI, and hook changes. That drop-in-style migration path is especially valuable when the repository has a straightforward Prettier setup and no required Prettier plugins.

The main reference for acting on this finding should be OXC’s official guide:

• https://oxc.rs/docs/guide/usage/formatter/migrate-from-prettier.html

That guide is more useful than a generic “swap prettier for oxfmt” suggestion because it covers:

• oxfmt --migrate=prettier
• config differences such as default printWidth
• script, CI, and hook updates
• Prettier plugin limitations and unsupported options

This rule is intentionally split by severity:

• warning: no visible Prettier plugins were detected at the repository root
• suggestion: visible Prettier plugins were detected, so compatibility should be reviewed before replacing Prettier

Current heuristic

The rule looks for:

• repository-root Prettier usage hints from files such as .prettierrc*, prettier.config.*, or package.json
• no visible repository-root Oxfmt usage

When to ignore it

Ignore this finding when:

• the repo depends on Prettier plugins that still matter for the current formatting path
• the workflow intentionally keeps Prettier as the authoritative formatter and migration has already been evaluated
• the repository uses Prettier only indirectly and the current formatter entrypoint has already been reviewed

Suggested verification

• Read OXC’s Migrate from Prettier guide before changing CI defaults
• Compare formatting step duration before and after introducing oxfmt
• Check whether formatted output stays acceptable on the same file set
• If Prettier plugins are present, confirm whether Oxfmt already covers the needed behavior natively

Sources

• https://oxc.rs/docs/guide/usage/formatter
• https://oxc.rs/docs/guide/usage/formatter/migrate-from-prettier
• https://oxc.rs/docs/guide/usage/formatter/config-file-reference