ecmascript-version-detector

ECMAScript Version Detection library.

Online demo

Go to https://azu.github.io/ecmascript-version-detector/

Install

Install with npm:

npm install ecmascript-version-detector

Usage

parse(code: string): {selector:string, version:string, node: Object, en: Object}[]

Parse code and return results.

const parse = require("ecmascript-version-detector").parse;
parse(`const x = 1 ** 2;`);
/*
[
    {
        "selector": "//BinaryExpression[@operator=='**']",
        "version": "2016",
        "en": {
            "name": "BinaryExpression exponentiation operator"
        },
        "node": {
            "type": "BinaryExpression",
            "start": 0,
            "end": 6,
            "loc": {
                "start": {
                    "line": 1,
                    "column": 0
                },
                "end": {
                    "line": 1,
                    "column": 6
                }
            },
            "left": {
                "type": "NumericLiteral",
                "start": 0,
                "end": 1,
                "loc": {
                    "start": {
                        "line": 1,
                        "column": 0
                    },
                    "end": {
                        "line": 1,
                        "column": 1
                    }
                },
                "extra": {
                    "rawValue": 1,
                    "raw": "1"
                },
                "value": 1
            },
            "operator": "**",
            "right": {
                "type": "NumericLiteral",
                "start": 5,
                "end": 6,
                "loc": {
                    "start": {
                        "line": 1,
                        "column": 5
                    },
                    "end": {
                        "line": 1,
                        "column": 6
                    }
                },
                "extra": {
                    "rawValue": 2,
                    "raw": "2"
                },
                "value": 2
            }
        }
    },
    ....
]
*/

Contributing

Pull requests and stars are always welcome.

How to add data?

1. mkdir data/<new-node-type>
2. add index.js to data/<new-node-type>
3. npm run build
4. Pull Request!!

index.js is following format:

// BooleanLiteral is `true` or `false`
// This is available since ECMAScript version 3
// Display name is "BooleanLiteral"
module.exports = {
    "selector": "//BooleanLiteral",
    "version": "3",
    "en": {
        "name": "BooleanLiteral",
        "link": "https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Boolean"
    }
};

• selector: the selector match the node type.
  • This project use ASTq query engine
  • This is similar to XPath query.
• version: the feature is available in the version
• en
  • name: display name
  • link: related link. e.g.) MDN link

For bugs and feature requests, please create an issue.

1. Fork it!
2. Create your feature branch: git checkout -b my-new-feature
3. Commit your changes: git commit -am 'Add some feature'
4. Push to the branch: git push origin my-new-feature
5. Submit a pull request :D

Resources

• babylon/spec.md at master · babel/babylon
  • AST Spec
• rse/astq: Abstract Syntax Tree (AST) Query Engine
  • XPath like Query engine for AST

Changelog

See Releases page.

Running tests

Install devDependencies and Run npm test:

npm i -d && npm test

Author

• github/azu
• twitter/azu_re

License

MIT © azu