noBiomeFirstException (JSON)

Language JSON (and super languages)

Summary

• Rule available since: v2.2.0
• Diagnostic Category: lint/suspicious/noBiomeFirstException
• This rule is recommended, meaning it is enabled by default.
• This rule has a safe fix.
• The default severity of this rule is error.

How to configure

biome.json

{
  "linter": {
    "rules": {
      "suspicious": {
        "noBiomeFirstException": "error"
      }
    }
  }
}

Description

Disallow ineffective ordering in files.includes patterns.

A pattern beginning with ! excludes matching paths. If an exclusion is first, no earlier pattern has included files for it to remove, so Biome matches no files. Start with an inclusion pattern, then add exclusions.

See the file exclusion guide for more examples.

Examples

Invalid

{
    "files": {
        "includes": ["!dist"]
    }
}

Valid

{
    "files": {
        "includes": ["src/**", "!dist"]
    }
}

Extended configurations

The catch-all pattern ** includes every path. When an extended configuration already starts with **, repeating that pattern at the start of the local configuration is redundant. Keep the inherited catch-all and add only the local exclusions.

Invalid

biome.json

{
    "extends": ["./base.json"],
    "files": {
        "includes": ["**", "!**/test"]
    }
}

base.json

{
    "files": {
        "includes": ["**", "!**/dist"]
    }
}

Valid

biome.json

{
    "extends": ["./base.json"],
    "files": {
        "includes": ["!**/test"]
    }
}

Related links

• Disable a rule
• Configure the code fix
• Rule options
• Source Code (Edit this Page)
• Test Cases