noApproximativeNumericConstant

Diagnostic Category: lint/suspicious/noApproximativeNumericConstant

JavaScript (and super languages)

Since: v1.3.0

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

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 │

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

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

let x = Math.LN10;

How to configure

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