useConsistentHeadingLevel (Markdown)

Language Markdown

Summary

Rule available since: v2.5.8
Diagnostic Category: lint/nursery/useConsistentHeadingLevel
This rule doesn’t have a fix.
The default severity of this rule is information.
Sources:
- Same as heading-increment

How to configure

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{
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  "linter": {
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    "rules": {
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      "nursery": {
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        "useConsistentHeadingLevel": "error"
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      }
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    }
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  }
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}

Description

Enforce that all heading levels are consistent and ordered.

In a Markdown document, the level of the headings should be consistent and grow only by one level at a time.

This rule catches cases where a heading skips one or more levels.

Examples

Invalid

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# Header 1
2

3
### Header 3

code-block.md:3:1 lint/nursery/useConsistentHeadingLevel  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ℹ This heading skipped a level.
  
    1 │ # Header 1
    2 │ 
  > 3 │ ### Header 3
      │ ^^^^^^^^^^^^
    4 │ 
  
  ℹ The previous heading has level1.
  
  > 1 │ # Header 1
      │ ^^^^^^^^^^
    2 │ 
    3 │ ### Header 3
  
  ℹ headings should follow a consistent level order. Failing to do so could cause issues when the file is transformed into HTML.
  
  ℹ This rule belongs to the nursery group, which means it is not yet stable and may change in the future. Visit https://biomejs.dev/linter/#nursery for more information.
  
  ℹ Safe fix: Change the level of the heading.
  
    3 │ ###·Header·3
      │   -

Valid

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# Header 1
2

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## Header 2