[brenttimmermans]

Summary

The README told nested package configs to extend only react.biome.json with "root": false, but in Biome 2.x a nested config doesn't inherit the root biome.json. Those packages silently fall back to Biome's defaults (double quotes, semicolons, tabs) and lose the base linter rules. The README now tells package configs to extend root.biome.json alongside the framework preset.

We can't fix this in the presets themselves: Biome ignores extends inside an extended config, so react.biome.json can't pull in root.biome.json. Upstream treats this as by design (biomejs/biome#1867) and closed the feature request (discussion #8257). The "//" shorthand only works as a plain string, so it can't be combined with a preset either.

Changes

• Monorepo section: correct how nested configs resolve, explain why presets can't include root, and update the package-level example to extend [root.biome.json, react.biome.json]
• Config composition: root must be listed in every config that uses a framework preset, including nested ones

Testing

Tested in a throwaway monorepo on Biome 2.5.15, with the package installed from a packed tarball:

• Nested config extending only react.biome.json: Biome defaults, and useBlockStatements doesn't fire
• Nested config extending root + react: single quotes, no semicolons, 2 spaces; useHookAtTopLevel and useBlockStatements fire; files in the root .gitignore are still skipped
• An extends inside a preset is silently ignored on 2.0.0, 2.2.0, 2.4.4 and 2.5.15, even when it points at a file that doesn't exist

Skills used

• None

Checklist

• Documented what's new
• Added in-code documentation (wherever needed)
• Wrote tests for new components/features
• Added analytics (wherever needed)

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