Checks if JS code is minified or uglified performantly.

Usage

import { isMinified } from 'is-minified-performant';

const source2 = `!function(e){function t(r){if(n[r])return n[r].exports;for(var i=[],o=0;o<256;++o)i[o]=(o+256).toString(16).substr(1);e.exports=r}};`;

isMinified(source) // true

const source1 = `
function main(foo = '') {
}
const bar = 1;
`;

isMinified(source) // false

How It Works

Use "Duck Typing" to detect whether source code is minified.

Duck typing in computer programming is an application of the duck test—"If it walks like a duck and it quacks like a duck, then it must be a duck"—In duck typing, an object's suitability is determined by the presence of certain methods and properties, rather than the type of the object itself.

From wiki/Duck_typing

• no space before return
• no space before and after if or else
• no space before and after =
• no space before and after var

Why the Package

I tried is-uglified which uses acorn parse, is-minified using RegExp, and is-minified-code using RegExp and sort, and finally found "Duck Typing" is the most performant 🚀 and efficient detect method and the correctness not lower than the above ones.

Benchmark Results

1 Check react.development.js not be minified. npm run benchmark-not-minified:

is-minified-performant#isMinified x 35,459 ops/sec ±0.97% (87 runs sampled)
is-uglified#isCodeUglified x 163 ops/sec ±3.73% (77 runs sampled)
is-minified#isMinifiedUsingRegexp x 25,229 ops/sec ±3.10% (84 runs sampled)
is-minified-code#isMinifiedUsingRegexpAndMedian x 881 ops/sec ±2.40% (81 runs sampled)

Check react.development.js not minified: the fastest is is-minified-performant#isMinified

This package's checking un-minified source code speed 1.4 times the second.

2 Check react.production.min.js is be minified. npm run benchmark-minified:

is-minified-performant#isMinified x 4,270,443 ops/sec ±1.58% (89 runs sampled)
is-uglified#isCodeUglified x 412 ops/sec ±5.71% (76 runs sampled)
is-minified#isMinifiedUsingRegexp x 240,459 ops/sec ±1.90% (88 runs sampled)
is-minified-code#isMinifiedUsingRegexpAndMedian x 81,651 ops/sec ±2.14% (87 runs sampled)

Check react.production.min.js minified: the fastest is is-minified-performant#isMinified

This package's checking minified source code speed 17 times the second.