useExponentiationOperator (JavaScript)

Language JavaScript (and super languages)

Summary

Rule available since: v1.0.0
Diagnostic Category: lint/style/useExponentiationOperator
This rule is recommended, meaning it is enabled by default.
This rule has a safe fix.
The default severity of this rule is information.
Sources:
- Same as prefer-exponentiation-operator
- Same as e18e/prefer-exponentiation-operator

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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        "useExponentiationOperator": "error"
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      }
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    }
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  }
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}

Description

Disallow the use of Math.pow in favor of the ** operator.

Introduced in ES2016, the infix exponentiation operator ** is an alternative for the standard Math.pow function. Infix notation is considered to be more readable and thus more preferable than the function notation.

Examples

Invalid

1
const foo = Math.pow(2, 8);

code-block.js:1:13 lint/style/useExponentiationOperator  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ℹ Use the '**' operator instead of 'Math.pow'.
  
  > 1 │ const foo = Math.pow(2, 8);
      │             ^^^^^^^^^^^^^^
    2 │ 
  
  ℹ Safe fix: Use the '**' operator instead of 'Math.pow'.
  
    1   │ - const·foo·=·Math.pow(2,·8);
      1 │ + const·foo·=·2·**·8;
    2 2 │

1
const bar = Math.pow(a, b);

code-block.js:1:13 lint/style/useExponentiationOperator  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ℹ Use the '**' operator instead of 'Math.pow'.
  
  > 1 │ const bar = Math.pow(a, b);
      │             ^^^^^^^^^^^^^^
    2 │ 
  
  ℹ Safe fix: Use the '**' operator instead of 'Math.pow'.
  
    1   │ - const·bar·=·Math.pow(a,·b);
      1 │ + const·bar·=·a·**·b;
    2 2 │

1
let baz = Math.pow(a + b, c + d);

code-block.js:1:11 lint/style/useExponentiationOperator  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ℹ Use the '**' operator instead of 'Math.pow'.
  
  > 1 │ let baz = Math.pow(a + b, c + d);
      │           ^^^^^^^^^^^^^^^^^^^^^^
    2 │ 
  
  ℹ Safe fix: Use the '**' operator instead of 'Math.pow'.
  
    1   │ - let·baz·=·Math.pow(a·+·b,·c·+·d);
      1 │ + let·baz·=·(a·+·b)·**·(c·+·d);
    2 2 │

1
let quux = Math.pow(-1, n);

code-block.js:1:12 lint/style/useExponentiationOperator  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ℹ Use the '**' operator instead of 'Math.pow'.
  
  > 1 │ let quux = Math.pow(-1, n);
      │            ^^^^^^^^^^^^^^^
    2 │ 
  
  ℹ Safe fix: Use the '**' operator instead of 'Math.pow'.
  
    1   │ - let·quux·=·Math.pow(-1,·n);
      1 │ + let·quux·=·(-1)·**·n;
    2 2 │

Valid

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const foo = 2 ** 8;
2

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const bar = a ** b;
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let baz = (a + b) ** (c + d);
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let quux = (-1) ** n;