applifier / babel-plugin-transform-builtin-extend

A plugin for Babel 6 supports extending from builtin types based on static analysis.

Babel Builtin Constructor extension plugin

This is a Babel 6 plugin to enable extending builtin types like "Error" and "Array" and such, which require special treatment and require static analysis to detect.

Usage

In your Babel 6 configuration, for example in a .babelrc you might have

{
    "plugins": [
        ["babel-plugin-transform-builtin-extend", {
            globals: ["Error", "Array"]
        }]
    ]
}

which would enable the plugin and configure it to look for any class extending Error or Array globals.

IE<=10

On older browsers that do not support reassigning the prototype of an existing object, you will need to enable the approximate mode, which will fall back to the Babel 5 behavior of using simple ES5 inheritance to approximate extending a class, though your results may vary depending on your goals.

{
    "plugins": [
        ["babel-plugin-transform-builtin-extend", {
            globals: ["Error", "Array"],
            approximate: true
        }]
    ]
}

Limitations

This plugin will only reles on assigning __proto__ for static property inheritance from parent constructors. If you are relying on this, it will not work on IE<=10 and any other browsers that don't support __proto__.