https://github.com/ruanyf/es-checker

A feature detection library for ECMAScript in node.js and browser.
https://github.com/ruanyf/es-checker

Last synced: 2 days ago
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A feature detection library for ECMAScript in node.js and browser.

• Host: GitHub
• URL: https://github.com/ruanyf/es-checker
• Owner: ruanyf
• Created: 2015-06-29T11:02:58.000Z (over 9 years ago)
• Default Branch: master
• Last Pushed: 2019-07-16T13:38:38.000Z (over 5 years ago)
• Last Synced: 2024-10-29T17:55:44.101Z (3 months ago)
• Language: JavaScript
• Homepage: http://ruanyf.github.io/es-checker
• Size: 563 KB
• Stars: 1,021
• Watchers: 45
• Forks: 152
• Open Issues: 0
• Metadata Files:
  • Readme: README.md

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README

        
ES-Checker is a feature detection library for ECMAScript in node.js and browser. Please visit [demo](http://ruanyf.github.io/es-checker/).

## How to use

### Command line

```bash

$ npm install -g es-checker

$ es-checker

```

![](./screenshot.png)

### Node.js

First install es-checker locally.

```bash

$ npm install --save es-checker

```

Then require it in your script.

```javascript

var Supports = require("es-checker");

if (Supports.letConst) {

  let x = 5;

} else {

  var x = 5;

}

```

The whole Api List please [see below](#api).

### Browser

First insert es-checker.js into your page.

```html

```

Then use `Supports` to decide which feature to use. Visit [demo](http://ruanyf.github.io/es-checker/).

```html

if (Supports.letConst) {

  let x = 5;

} else {

  var x = 5;

}

```

The whole API List please [see below](#api).

## API

This library is derived from [es-feature-tests](https://github.com/getify/es-feature-tests). The following API is copied from it. Visit [FeatureTests.io](https://featuretests.io/details) for more information, including how to test a feature by yourself.

- **letConst**: let and const

- **defaultParameter**: default function parameter values

- **spreadRest**: ... operator

- **destructuring**: destructuring assignments/declarations for arrays and objects

- **parameterDestructuring**: destructuring for function parameters

- **templateString**: `..` Template String Literals

- **forOf**: for (var v of something) { .. }

- **arrow**: x => x * x

- **generator**: function *foo() { .. }

- **conciseMethodProperty**: o = { b() { .. }, a }

- **computedProperty**: o = { ["a" + "b"]: 42 }

- **moduleExport**: In modules, export default foo = 42

- **moduleImport**: In modules, import bar from "foo"

- **class**: class A extends B { .. }

- **numericLiteral**: Octal and binary literal forms (0o1, 0b10)

- **oldOctalLiteral**: Old octal literal invalid now (01)

- **symbol**: Symbol primitive

- **unicodeEscape**: Unicode code-point escape form in string literals ('\u{20BB7}')

- **unicodeIdentifier**: Unicode code-point escape form in identifier names (\u{20BB7} = 42)

- **unicodeRegExp**: Unicode code-point escape form in regular expressions (/\u{20BB7}/u)

- **stickyRegExp**: y flag for sticky regular expressions

- **letTDZ**: TDZ error for too-early access of let or const declarations

- **constRedef**: Redefinition of const declarations not allowed

- **objectProto**: __proto__ in object literal definition sets [[Prototype]] link

- **objectSuper**: super allowed in object methods

- **extendNatives**: class ABC extends Array { .. }

- **tco**: Tail-call optimization for function calls and recursion

- **symbolImplicitCoercion**: Symbols can't be implicitly coerced (Symbol("a") + "")

- **functionNameInfernece**: Inferences for function name property for anonymous functions

- **objectStatics**: Static functions added to Object

- **arrayStatics**: Static functions added to Array

- **arrayMethods**: Methods added to Array.prototype

- **typedArrays**: TypedArrays like Uint8Array (technically a web platform feature long before ES6)

- **typedArrayStatics**: Some Array statics (like from(..)) added to the TypedArray constructors

- **typedArrayMethods**: Some Array methods (like map(..)) added to the TypedArray prototypes

- **stringMethods**: Methods added to String.prototype

- **numberStatics**: Static functions added to Number

- **mathStatics**: Static functions added to Math

- **collections**: Collections added (Map, Set, WeakMap, WeakSet)

- **proxy**: Proxies

- **promise**: Promises

- **reflect**: Reflect

## Licensed

MIT