noPrecisionLoss

JavaScript (and super languages)

Summary

• Rule available since: v1.0.0
• Diagnostic Category: lint/correctness/noPrecisionLoss
• 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-loss-of-precision
  • Same as @typescript-eslint/no-loss-of-precision
  • Same as lossy_float_literal

How to configure

biome.json

{
  "linter": {
    "rules": {
      "correctness": {
        "noPrecisionLoss": "error"
      }
    }
  }
}

Description

Disallow literal numbers that lose precision

Examples

Invalid

const x = 9007199254740993

code-block.js:1:11 lint/correctness/noPrecisionLoss ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ✖ This number literal will lose precision at runtime.
  
  > 1 │ const x = 9007199254740993
      │           ^^^^^^^^^^^^^^^^
    2 │ 
  
  ℹ The value at runtime will be 9007199254740992
  

const x = 5.123000000000000000000000000001

code-block.js:1:11 lint/correctness/noPrecisionLoss ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ✖ This number literal will lose precision at runtime.
  
  > 1 │ const x = 5.123000000000000000000000000001
      │           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    2 │ 
  
  ℹ The value at runtime will be 5.123
  

const x = 0x20000000000001

code-block.js:1:11 lint/correctness/noPrecisionLoss ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ✖ This number literal will lose precision at runtime.
  
  > 1 │ const x = 0x20000000000001
      │           ^^^^^^^^^^^^^^^^
    2 │ 
  
  ℹ The value at runtime will be 9007199254740992
  

const x = 0x2_000000000_0001;

code-block.js:1:11 lint/correctness/noPrecisionLoss ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ✖ This number literal will lose precision at runtime.
  
  > 1 │ const x = 0x2_000000000_0001;
      │           ^^^^^^^^^^^^^^^^^^
    2 │ 
  
  ℹ The value at runtime will be 9007199254740992
  

Valid

const x = 12345
const x = 123.456
const x = 123e34
const x = 12300000000000000000000000
const x = 0x1FFFFFFFFFFFFF
const x = 9007199254740991
const x = 9007_1992547409_91

Related links

• Disable a rule
• Configure the code fix
• Rule options
• Source Code
• Test Cases