@typhonjs/babel-parser
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Provides a front end for Javascript / Typescript AST generation by Babel parser with TyphonJS plugin support.
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[](https://www.npmjs.com/package/@typhonjs/babel-parser)
[](https://en.wikipedia.org/wiki/Indent_style#Allman_style)
[](https://github.com/typhonjs-node-ast/babel-parser/blob/master/LICENSE)
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[](https://travis-ci.org/typhonjs-node-ast/babel-parser)
[](https://codecov.io/github/typhonjs-node-ast/babel-parser)
[](https://david-dm.org/typhonjs-node-ast/babel-parser)
Provides a front end for Javascript / Typescript AST generation by Babel parser with TyphonJS plugin support. By default all Babel parser plugins are enabled except for `flow` and there is a handy override mechanism to change relevant defaults without having to provide a full set of options to the parser.
This NPM module can be installed as a dependency in `package.json` as follows:
```js
"dependencies": {
"@typhonjs/babel-parser": "^0.2.0"
}
```
Please see [Babel Parser Docs](https://babeljs.io/docs/en/babel-parser) for specific plugin information. By default `babel-parser` enables all plugins except for `flow` as it is incompatible with the `typescript` plugin. Also by default the `decorators` plugins is enabled and not compatible with `decorators-legacy`.
The default Babel parser options is as follows:
```
const s_DEFAULT_BABELPARSER_OPTIONS =
{
plugins: ['asyncGenerators', 'bigInt', 'classProperties', 'classPrivateProperties', 'classPrivateMethods',
['decorators', { decoratorsBeforeExport: false }], 'doExpressions', 'dynamicImport',
'exportDefaultFrom', 'exportNamespaceFrom', 'functionBind', 'functionSent', 'importMeta',
'jsx', 'logicalAssignment', 'nullishCoalescingOperator', 'numericSeparator', 'objectRestSpread',
'optionalCatchBinding', 'optionalChaining', ['pipelineOperator', { proposal: 'minimal' }], 'throwExpressions',
'typescript']
};
```
There is a way to provide additional override directives to `babel-parser` which modifies the default babel parser options above. This only activates when no manual parser options are provided. A third parameter can be passed into `parse` which will modify the default parameters above. For example Flow is supported by passing in `{ flow: true }` as the override object. This allows flow to be enabled and typescript to be disabled without providing the full babel parser options manually. A few other optional overrides are available:
```
{
decoratorsBeforeExport: <boolean>, // Sets the associated configuration value
decoratorsLegacy: true, // Removes the proposal decorators plugin for `decorators-legacy`
flow: true, // Enables flow / disables typescript plugins
pipelineOperatorProposal: <string> // Sets the proposal field of pipelineOperator plugin
}
```
An ES6 example follows:
```js
import BabelParser from '@typhonjs/babel-parser';
// Basic usage to parse text / source code with default options.
const ast = BabelParser.parse(`<some JS or Typescript source code>`);
// Providing custom options
const parserOptions = { plugins: [<any parser options desired to be enabled>] };
const ast = BabelParser.parse(`<some JS or Typescript source code>`, parserOptions);
// Basic usage with default options, but with an override to disable Typescript and enable Flow plugins
const ast = BabelParser.parse(`<some JS w/ Flow typing>`, void 0, { flow: true });
```
`@typhonjs/babel-parser` may be loaded as a TyphonJS plugin with [typhonjs-plugin-manager](https://www.npmjs.com/package/typhonjs-plugin-manager) and if an eventbus is associated the following event categories are registered:
`typhonjs:babel:parser:parse` - invokes `BabelParser.parse`