Skip to content
Biome
Docs Blog Playground

noGlobalIsFinite (since v1.0.0)

Diagnostic Category: lint/suspicious/noGlobalIsFinite

Use Number.isFinite instead of global isFinite.

Number.isFinite() and isFinite() do not have the same behavior. When the argument to isFinite() is not a number, the value is first coerced to a number. Number.isFinite() does not perform this coercion. Therefore, it is a more reliable way to test whether a number is finite.

Examples

Section titled Examples

Invalid

Section titled Invalid
isFinite(false); // true
code-block.js:1:1 lint/suspicious/noGlobalIsFinite  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ✖ isFinite is unsafe. It attempts a type coercion. Use Number.isFinite instead.
  
  > 1 │ isFinite(false); // true
      │ ^^^^^^^^
    2 │ 
  
  ℹ See the MDN documentation for more details.
  
  ℹ Unsafe fix: Use Number.isFinite instead.
  
    1   │ - isFinite(false);·//·true
      1 │ + Number.isFinite(false);·//·true
    2 2 │

Valid

Section titled Valid
Number.isFinite(false); // false
Section titled Related links