@putout/plugin-math

@putout/plugin-math

🐊Putout plugin helps with Math.

Install

npm i @putout/plugin-math -D

Rules

• ✅ apply-exponentiation;
• ✅ apply-multiplication;
• ✅ apply-numeric-separators;
• ✅ convert-sqrt-to-hypot;
• ✅ declare;
• ✅ remove-unchanged-zero-declarations;

{
    "rules": {
        "math/apply-exponentiation": "on",
        "math/apply-multiplication": "on",
        "math/apply-numeric-separators": "on",
        "math/convert-sqrt-to-hypot": "on",
        "math/declare": "on",
        "math/remove-unchanged-zero-declarations": "on"
    }
}

convert-sqrt-to-hypot

The Math.hypot() function returns the square root of the sum of squares of its arguments.

(c) MDN

Convert Math.sqrt() to Math.hypot(). Check out in 🐊Putout Editor.

❌ Example of incorrect code

Math.sqrt(a ** 2, b ** 2);

✅ Example of correct code

Math.hypot(a, b);

apply-exponentiation

• The Math.pow() static method, given two arguments, base and exponent, returns baseexponent.
• The exponentiation operator (**) returns the result of raising the first operand to the power of the second operand. It is equivalent to Math.pow, except it also accepts BigInts as operands.

(c) MDN

❌ Example of incorrect code

Math.pow(2, 4);

✅ Example of correct code

2 ** 4;

Comparison

Linter	Rule	Fix
🐊 Putout	convert-math-pow	✅
⏣ ESLint	prefer-exponentiation-operator	✅

apply-multiplication

Multiplying two numbers stored internally as integers (which is only possible with AsmJS with imul is the only potential circumstance where Math.imul() may prove performant in current browsers.

(c) MDN

Check out in 🐊Putout Editor.

❌ Example of incorrect code

const a = Math.imul(b, c);

✅ Example of correct code

const a = b * c;

apply-numeric-separators

To improve readability for numeric literals, underscores (_) can be used as separators.

(c) MDN

❌ Example of incorrect code

const t = 10000000;

✅ Example of correct code

const t = 10_000_000;

declare

The Math.round() static method returns the value of a number rounded to the nearest integer.

(c) MDN

❌ Example of incorrect code

round(bLength / aLength) > 3;

✅ Example of correct code

const {round} = Math;
round(bLength / aLength) > 3;

remove-unchanged-zero-declarations

Checkout in 🐊Putout Editor.

❌ Example of incorrect code

for (let index = 0; index < n; index++) {
    const tokenDelta = 0;
    const templateDelta = 0;
    
    for (let templateIndex = 0; templateIndex < templateTokensLength; templateIndex++) {
        const currentTokenIndex = index + templateIndex - tokenDelta;
        const currentToken = tokens[currentTokenIndex];
        
        end = currentTokenIndex + tokenDelta;
    }
}

✅ Example of correct code

for (let index = 0; index < n; index++) {
    for (let templateIndex = 0; templateIndex < templateTokensLength; templateIndex++) {
        const currentTokenIndex = index + templateIndex;
        const currentToken = tokens[currentTokenIndex];
        
        end = currentTokenIndex;
    }
}

License

MIT