noLabelVar

JavaScript (and super languages)

Summary

• Rule available since: v1.0.0
• Diagnostic Category: lint/suspicious/noLabelVar
• This rule is recommended, which means is enabled by default.
• This rule doesn’t have a fix.
• The default severity of this rule is error.
• Sources:
  • Same as no-label-var

How to configure

biome.json

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

Description

Disallow labels that share a name with a variable

Examples

Invalid

const x1 = "test";
x1: expr;

code-block.js:2:1 lint/suspicious/noLabelVar ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ✖ Do not use the x1 variable name as a label
  
    1 │ const x1 = “test”;
  > 2 │ x1: expr;
      │ ^^
    3 │ 
  
  ℹ The variable is declared here
  
  > 1 │ const x1 = “test”;
      │       ^^
    2 │ x1: expr;
    3 │ 
  
  ℹ Creating a label with the same name as an in-scope variable leads to confusion.
  

Valid

const x = "test";
z: expr;

Related links

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• Rule options
• Source Code
• Test Cases