纯JS Packages

Returns true if any values exist, false if empty. Works for booleans, functions, numbers, strings, nulls, objects and arrays.

Tiny JavaScript tokenizer.

Serialize JavaScript to a superset of JSON that includes regular expressions and functions.

Core istanbul API for JS code coverage

Get and robustly cache all JS language-level intrinsics at first require time

Robustly `.call.bind()` a function

JavaScript parser, mangler/compressor and beautifier toolkit

A dictionary of file extensions and associated module loaders.

Is this an arguments object? It's a harder question than you think.

Array-slice method. Slices `array` from the `start` index up to, but not including, the `end` index.

Use the :focus-visible pseudo-selector in CSS

Style elements relative to other elements in CSS

Style form elements when they are empty

Strip line and/or block comments from a string. Blazing fast, and works with JavaScript, Sass, CSS, Less.js, and a number of other languages.

A pure javascript JPEG encoder and decoder

Like `extend` but only copies missing properties/values to the target object.

Spectacular Test Runner for JavaScript.

Fast, small, efficient JavaScript memoization lib to memoize JS functions

A JavaScript (JS) Map or Similar object polyfill if Map is not available.

Raw browser/feature support data from caniuse.com