noExcessiveLinesPerFile (JavaScript)

Language

• CSS
• GraphQL
• HTML
• JavaScript (and super languages)

Summary

• Rule available since: v2.3.12
• Diagnostic Category: lint/style/noExcessiveLinesPerFile
• This rule isn’t recommended, so you need to enable it.
• This rule doesn’t have a fix.
• The default severity of this rule is information.
• Sources:
  • Inspired from max-lines

How to configure

biome.json

{
  "linter": {
    "rules": {
      "style": {
        "noExcessiveLinesPerFile": "error"
      }
    }
  }
}

Description

Restrict the number of lines in a file.

Large files tend to do many things and can make it hard to follow what’s going on. This rule can help enforce a limit on the number of lines in a file.

Examples

Invalid

The following example will show a diagnostic when maxLines is set to 2:

biome.json

{
  "linter": {
    "rules": {
      "style": {
        "noExcessiveLinesPerFile": {
          "level": "on",
          "options": {
            "maxLines": 2
          }
        }
      }
    }
  }
}

const a = 1;
const b = 2;
const c = 3;

code-block.js:1:1 lint/style/noExcessiveLinesPerFile ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ℹ This file has too many lines (3). Maximum allowed is 2.
  
  > 1 │ const a = 1;
      │ ^^^^^^^^^^^^
  > 2 │ const b = 2;
  > 3 │ const c = 3;
      │ ^^^^^^^^^^^^
    4 │ 
  
  ℹ Consider splitting this file into smaller files.
  

Valid

const a = 1;
const b = 2;

Options

maxLines

This option sets the maximum number of lines allowed in a file. If the file exceeds this limit, a diagnostic will be reported.

Default: 300

Examples

The default value for maxLines is 300. The following example shows how to set the maxLines option to a smaller value. It reports a diagnostic because the file has more than 4 lines:

biome.json

{
  "linter": {
    "rules": {
      "style": {
        "noExcessiveLinesPerFile": {
          "level": "on",
          "options": {
            "maxLines": 4
          }
        }
      }
    }
  }
}

const a = 1;
const b = 2;
const c = 3;
const d = 4;
const e = 5;

code-block.js:1:1 lint/style/noExcessiveLinesPerFile ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ℹ This file has too many lines (5). Maximum allowed is 4.
  
  > 1 │ const a = 1;
      │ ^^^^^^^^^^^^
  > 2 │ const b = 2;
  > 3 │ const c = 3;
  > 4 │ const d = 4;
  > 5 │ const e = 5;
      │ ^^^^^^^^^^^^
    6 │ 
  
  ℹ Consider splitting this file into smaller files.
  

skipBlankLines

When this option is set to true, blank lines are not counted towards the maximum line limit.

Default: false

Examples

The following example shows how skipBlankLines can prevent a diagnostic by excluding blank lines from the total count:

biome.json

{
  "linter": {
    "rules": {
      "style": {
        "noExcessiveLinesPerFile": {
          "level": "on",
          "options": {
            "maxLines": 2,
            "skipBlankLines": true
          }
        }
      }
    }
  }
}

const a = 1;


const b = 2;

Suppressions

If you need to exceed the line limit in a specific file, you can suppress this rule at the top of the file:

biome.json

{
  "linter": {
    "rules": {
      "style": {
        "noExcessiveLinesPerFile": {
          "level": "on",
          "options": {
            "maxLines": 2
          }
        }
      }
    }
  }
}

// biome-ignore-all lint/style/noExcessiveLinesPerFile: generated file
const a = 1;
const b = 2;
const c = 3;

Related links

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• Source Code (Edit this Page)
• Test Cases