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

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

Description

Disallow constants whose string value is the same as their uppercase name.

A declaration such as const FOO = "FOO" adds an unnecessary name without providing additional meaning. Use the string directly instead. The rule ignores exported constants and constants referenced more than once.

Examples

Invalid

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const FOO = "FOO";
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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

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

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

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