noUnmatchableAnbSelector (CSS)

Language CSS

Summary

Rule available since: v1.8.0
Diagnostic Category: lint/correctness/noUnmatchableAnbSelector
This rule is recommended, meaning it is enabled by default.
This rule doesn’t have a fix.
The default severity of this rule is error.
Sources:
- Same as selector-anb-no-unmatchable
- Inspired from css/no-unmatchable-selectors

How to configure

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{
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  "linter": {
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    "rules": {
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      "correctness": {
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        "noUnmatchableAnbSelector": "error"
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      }
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    }
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  }
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}

Description

Disallow An+B formulas that cannot select an element.

Pseudo-classes such as :nth-child() use an An+B formula to describe element positions: A controls the interval and B is the starting offset. Element positions begin at 1, so a formula that produces only 0 can never match.

See the CSS syntax specification for the complete formula syntax.

Examples

Invalid

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a:nth-child(0) {}

code-block.css:1:13 lint/correctness/noUnmatchableAnbSelector ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ✖ This selector will never match any elements.
  
  > 1 │ a:nth-child(0) {}
      │             ^
    2 │ 
  
  ℹ Avoid using An+B selectors that always evaluate to 0.
  
  ℹ For more details, see the official spec for An+B selectors.

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a:nth-last-child(0n) {}

code-block.css:1:18 lint/correctness/noUnmatchableAnbSelector ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ✖ This selector will never match any elements.
  
  > 1 │ a:nth-last-child(0n) {}
      │                  ^^
    2 │ 
  
  ℹ Avoid using An+B selectors that always evaluate to 0.
  
  ℹ For more details, see the official spec for An+B selectors.

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a:nth-of-type(0n+0) {}

code-block.css:1:15 lint/correctness/noUnmatchableAnbSelector ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ✖ This selector will never match any elements.
  
  > 1 │ a:nth-of-type(0n+0) {}
      │               ^^^^
    2 │ 
  
  ℹ Avoid using An+B selectors that always evaluate to 0.
  
  ℹ For more details, see the official spec for An+B selectors.

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a:nth-last-of-type(0 of a) {}

code-block.css:1:20 lint/correctness/noUnmatchableAnbSelector ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ✖ This selector will never match any elements.
  
  > 1 │ a:nth-last-of-type(0 of a) {}
      │                    ^^^^^^
    2 │ 
  
  ℹ Avoid using An+B selectors that always evaluate to 0.
  
  ℹ For more details, see the official spec for An+B selectors.

Valid

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a:nth-child(1) {}

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a:nth-last-child(1n) {}

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a:nth-of-type(1n+0) {}

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a:nth-last-of-type(1 of a) {}