Biome v1.6

Emanuele Stoppa & Biome Core Team, Biome Maintainers

March 8, 2024

Update Biome using the following commands:

npm install --save-dev --save-exact @biomejs/biome@latest
npx @biomejs/biome migrate

Partial support for Astro, Svelte and Vue files

In this release, we’re happy to provide partial support for Astro, Svelte and Vue files. What does partial support mean?

While the team is working on a unified data structure for HTML-ish languages, we discovered that we could provide Biome functionalities to those files with just a few changes, albeit with some limitations.

This means that Biome is able to analyze the JavaScript/TypeScript portion of said files, and all features are available: formatting, linting and import sorting! Here’s an example of what you should expect in terms of developer experience:

Screenshot of Biome linting in action for an Astro file in VSCode

Make sure to read the documentation about expectations and limitations.

Configuration, lighter and more powerful

Support for `biome.jsonc`

Biome now accepts the biome.jsonc file as configuration! You can insert all the comments you want in there.

`extends` resolves dependencies

From this version, Biome can use the extends property to resolve other configuration files that are inside installed dependencies.

There are few important steps in order to make the configuration discoverable. The file must be exported from a "module" package, and the file should be exported in your package.json like this:

{
  "name": "@shared-configs",
  "type": "module",
  "exports": {
    "./biome": "./biome.json"
  }
}

This set up allows to expose a specifier @shared-configs/biome, which you use inside your biome.json file.

{
  "extends": ["@shared-configs/biome"]
}

The resolution of the dependencies is powered by the library oxc-resolver, one of the many libraries provided by the OXC project. It’s battle-tested and spec compliant!

Reduced memory footprint

We reduced the size our configuration by a factor of 6.5! This change might not have massive effects on the speed of the program, but it greatly reduced the memory used when running the CLI or the LSP.

New formatting options

Other than fixes, the formatter provides two new options that should improve the compatibility with Prettier.

Option `attributePosition`

When formatter.attributePosition has the value multiline, all attributes of HTML-ish languages (JSX/TSX as for time of writing) will be collapsed on multiple lines regardless of their numbers:

With variant `auto` (default)

The attributes are automatically formatted, and they will collapse in multiple lines only when they hit certain criteria.

<Button as="link" style="primary" href="https://example.com">
    Hit me
</Button>

With variant `multiline`

The attributes are always formatted on multiple lines, regardless.

<Button
    as="link"
    style="primary"
    href="https://example.com"
>
    Hit me
</Button>

The contributor @octoshikari implemented this new feature by themselves! Huge thank you for helping the Biome project.

Option `json.formatter.trailingCommas`

Previously, Biome parser introduced an option that would allow to parse JSON and JSONC files that contained a trailing comma. This was required to ease the friction caused by other tools that tolerate trailing commas by default (e.g. VSCode, Prettier, etc.).

Unfortunately, our formatter wasn’t as tolerant. But with this release, we’ve introduced the option json.formatter.trailingCommas. It allows you to apply the same rules as with js.formatter.trailingComma.

With variant `none` (default)

The formatter removes the trailing comma upon formatting.

{
    "lorem": "ipsum",
    "lorem": "ipsum",
    "lorem": "ipsum",
    "lorem": "ipsum_last"
}

With variant `all`

The formatter adds the trailing comma upon formatting.

{
    "lorem": "ipsum",
    "lorem": "ipsum",
    "lorem": "ipsum",
    "lorem": "ipsum_last",
}

Easier migration from Prettier

This release introduces a new command called biome migrate prettier. This command will read your Prettier .prettierrc/prettier.json and .prettierignore, and attempt to port its options and globs in Biome.

Given a prettier.json file, Biome will modify the existing configuration file to match Prettier’s options:

{ "useTabs": false, "semi": true, "singleQuote": true }

{
  "formatter": {
    "enabled": true,
    "formatWithErrors": false,
    "indentStyle": "space",
    "indentWidth": 2,
    "lineEnding": "lf",
    "lineWidth": 80,
    "attributePosition": "auto"
  },
  "linter": { "enabled": true },
  "javascript": {
    "formatter": {
      "jsxQuoteStyle": "double",
      "quoteProperties": "asNeeded",
      "trailingCommas": "all",
      "semicolons": "always",
      "arrowParentheses": "always",
      "bracketSpacing": true,
      "bracketSameLine": false,
      "quoteStyle": "single",
      "attributePosition": "auto"
    }
  }
}

Linter

Promoted rules

New rules are incubated in the nursery group. Once stable, we promote them to a stable group. The following rules are promoted:

Additionally, the following rules are now recommended:

Removed rules

Remove nursery/useGroupedTypeImport. The rule style/useImportType covers the behavior of this rule.

New rules

New rules are now available:

Miscellaneous

We drastically reduced the number of protected files, which means you can now format your package.json, tsconfig.json, etc. with Biome. Lock files are still considered protected.
The CLI now does a better job at reporting the total number of files and the files that were really changed.
When a diagnostic shows a file name on the terminal that is integrated with your editor, you can click it and the editor will open the file for you.
The command biome rage now accepts two nice options: --formatter and --linter.
We removed some superfluous error diagnostic when running the biome check command.