noShoutyConstants (JavaScript)

Language JavaScript (and super languages)

Summary

• Rule available since: v1.0.0
• Diagnostic Category: lint/style/noShoutyConstants
• This rule isn’t recommended, so you need to enable it.
• This rule has an unsafe fix.
• The default severity of this rule is information.

How to configure

biome.json

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

Description

Disallow the use of constants which its value is the upper-case version of its name.

Examples

Invalid

const FOO = "FOO";
console.log(FOO);

code-block.js:1:7 lint/style/noShoutyConstants  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ℹ Redundant constant declaration.
  
  > 1 │ const FOO = "FOO";
      │       ^^^^^^^^^^^
    2 │ console.log(FOO);
    3 │ 
  
  ℹ Used here.
  
    1 │ const FOO = "FOO";
  > 2 │ console.log(FOO);
      │             ^^^
    3 │ 
  
  ℹ You should avoid declaring constants with a string that's the same
        value as the variable name. It introduces a level of unnecessary
        indirection when it's only two additional characters to inline.
  
  ℹ Unsafe fix: Use the constant value directly
  
    1   │ - const·FOO·=·"FOO";
    2   │ - console.log(FOO);
      1 │ + 
      2 │ + console.log("FOO");
    3 3 │   
  

Valid

let FOO = "FOO";
console.log(FOO);

export const FOO = "FOO";
console.log(FOO);

function f(FOO = "FOO") {
    return FOO;
}

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