135 lines
2.7 KiB
Markdown
135 lines
2.7 KiB
Markdown
# babel-plugin-transform-es2015-modules-commonjs
|
|
|
|
> This plugin transforms ES2015 modules to [CommonJS](http://wiki.commonjs.org/wiki/Modules/1.1).
|
|
|
|
## Example
|
|
|
|
**In**
|
|
|
|
```javascript
|
|
export default 42;
|
|
```
|
|
|
|
**Out**
|
|
|
|
```javascript
|
|
Object.defineProperty(exports, "__esModule", {
|
|
value: true
|
|
});
|
|
|
|
exports.default = 42;
|
|
```
|
|
|
|
## Installation
|
|
|
|
```sh
|
|
npm install --save-dev babel-plugin-transform-es2015-modules-commonjs
|
|
```
|
|
|
|
## Usage
|
|
|
|
### Via `.babelrc` (Recommended)
|
|
|
|
**.babelrc**
|
|
|
|
```js
|
|
// without options
|
|
{
|
|
"plugins": ["transform-es2015-modules-commonjs"]
|
|
}
|
|
|
|
// with options
|
|
{
|
|
"plugins": [
|
|
["transform-es2015-modules-commonjs", {
|
|
"allowTopLevelThis": true
|
|
}]
|
|
]
|
|
}
|
|
```
|
|
|
|
### Via CLI
|
|
|
|
```sh
|
|
babel --plugins transform-es2015-modules-commonjs script.js
|
|
```
|
|
|
|
### Via Node API
|
|
|
|
```javascript
|
|
require("babel-core").transform("code", {
|
|
plugins: ["transform-es2015-modules-commonjs"]
|
|
});
|
|
```
|
|
|
|
## Options
|
|
|
|
### `loose`
|
|
|
|
`boolean`, defaults to `false`.
|
|
|
|
As per the spec, `import` and `export` are only allowed to be used at the top
|
|
level. When in loose mode these are allowed to be used anywhere.
|
|
|
|
And by default, when using exports with babel a non-enumerable `__esModule` property
|
|
is exported.
|
|
|
|
```javascript
|
|
var foo = exports.foo = 5;
|
|
|
|
Object.defineProperty(exports, "__esModule", {
|
|
value: true
|
|
});
|
|
```
|
|
|
|
In environments that don't support this you can enable loose mode on `babel-plugin-transform-es2015-modules-commonjs`
|
|
and instead of using `Object.defineProperty` an assignment will be used instead.
|
|
|
|
```javascript
|
|
var foo = exports.foo = 5;
|
|
exports.__esModule = true;
|
|
```
|
|
|
|
### `strict`
|
|
|
|
`boolean`, defaults to `false`
|
|
|
|
By default, when using exports with babel a non-enumerable `__esModule` property
|
|
is exported. In some cases this property is used to determine if the import _is_ the
|
|
default export or if it _contains_ the default export.
|
|
|
|
```javascript
|
|
var foo = exports.foo = 5;
|
|
|
|
Object.defineProperty(exports, "__esModule", {
|
|
value: true
|
|
});
|
|
```
|
|
|
|
In order to prevent the `__esModule` property from being exported, you can set
|
|
the `strict` option to `true`.
|
|
|
|
### `noInterop`
|
|
|
|
`boolean`, defaults to `false`
|
|
|
|
By default, when using exports with babel a non-enumerable `__esModule` property
|
|
is exported. This property is then used to determine if the import _is_ the default
|
|
export or if it _contains_ the default export.
|
|
|
|
```javascript
|
|
"use strict";
|
|
|
|
var _foo = require("foo");
|
|
|
|
var _foo2 = _interopRequireDefault(_foo);
|
|
|
|
function _interopRequireDefault(obj) {
|
|
return obj && obj.__esModule ? obj : { default: obj };
|
|
}
|
|
```
|
|
|
|
In cases where the auto-unwrapping of `default` is not needed, you can set the
|
|
`noInterop` option to `true` to avoid the usage of the `interopRequireDefault`
|
|
helper (shown in inline form above).
|