noApproximativeNumericConstant

JavaScript (and super languages)

Summary

Rule available since: v1.3.0
Diagnostic Category: lint/suspicious/noApproximativeNumericConstant
This rule is recommended, which means is enabled by default.
This rule has an unsafe fix.
The default severity of this rule is error.
Sources:
- Same as approx_constant

Description

Use standard constants instead of approximated literals.

Usually, the definition in the standard library is more precise than what people come up with or the used constant exceeds the maximum precision of the number type.

Examples

Invalid

1
let x = 3.141;

code-block.js:1:9 lint/suspicious/noApproximativeNumericConstant  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━

  ✖ Prefer constants from the standard library.
  
  > 1 │ let x = 3.141;
      │         ^^^^^
    2 │ 
  
  ℹ Unsafe fix: Use Math.PI instead.
  
    1   │ - let·x·=·3.141;
      1 │ + let·x·=·Math.PI;
    2 2 │

1
let x = 2.302;

code-block.js:1:9 lint/suspicious/noApproximativeNumericConstant  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━

  ✖ Prefer constants from the standard library.
  
  > 1 │ let x = 2.302;
      │         ^^^^^
    2 │ 
  
  ℹ Unsafe fix: Use Math.LN10 instead.
  
    1   │ - let·x·=·2.302;
      1 │ + let·x·=·Math.LN10;
    2 2 │

Valid

1
let x = Math.PI;
2
let y = 3.14;

1
let x = Math.LN10;

How to configure

1
{
2
  "linter": {
3
    "rules": {
4
      "suspicious": {
5
        "noApproximativeNumericConstant": "error"
6
      }
7
    }
8
  }
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}