1. module rollup-plugin-babel
   1. function rollup-plugin-babel ( options )

module rollup-plugin-babel

function rollup-plugin-babel ( options )

• description and source-code

  function babel( options ) {
  	options = assign( {}, options || {} );
  	var inlineHelpers = {};
  
  	var filter = rollupPluginutils.createFilter( options.include, options.exclude );
  	delete options.include;
  	delete options.exclude;
  
  	if ( options.sourceMap !== false ) { options.sourceMaps = true; }
  	if ( options.sourceMaps !== false ) { options.sourceMaps = true; }
  	delete options.sourceMap;
  
  	var runtimeHelpers = options.runtimeHelpers;
  	delete options.runtimeHelpers;
  
  	var externalHelpers;
  	if ( options.externalHelpers ) { externalHelpers = true; }
  	delete options.externalHelpers;
  
  	var externalHelpersWhitelist = null;
  	if ( options.externalHelpersWhitelist ) { externalHelpersWhitelist = options.externalHelpersWhitelist; }
  	delete options.externalHelpersWhitelist;
  
  	var warn = function (msg) { return console.warn(msg); }; // eslint-disable-line no-console
  
  	return {
  		name: 'babel',
  
  		options: function options$1 ( options ) {
  			warn = options.onwarn || warn;
  		},
  
  		resolveId: function resolveId ( id ) {
  			if ( id === HELPERS ) { return id; }
  		},
  
  		load: function load ( id ) {
  			if ( id === HELPERS ) {
  				var pattern = new RegExp( ("babelHelpers\\.(" + (keywordHelpers.join('|')) + ")"), 'g' );
  
  				var helpers = babelCore.buildExternalHelpers( externalHelpersWhitelist, 'var' )
  					.replace( pattern, 'var _$1' )
  					.replace( /^babelHelpers\./gm, 'export var ' ) +
  					"\n\nexport { " + (keywordHelpers.map( function (word) { return ("_" + word + " as " + word); }).join( ', ')) + " }";
  
  				return helpers;
  			}
  		},
  
  		transform: function transform$1 ( code, id ) {
  			if ( !filter( id ) ) { return null; }
  			if ( id === HELPERS ) { return null; }
  
  			var helpers = preflightCheck( options, path.dirname( id ) );
  			var localOpts = assign({ filename: id }, options );
  
  			var transformed = babelCore.transform( code, localOpts );
  			var ref = transformed.metadata;
  			var usedHelpers = ref.usedHelpers;
  
  			if ( usedHelpers.length ) {
  				if ( helpers === BUNDLED ) {
  					if ( !externalHelpers ) {
  						transformed.code += "\n\nimport * as babelHelpers from '" + HELPERS + "';";
  					}
  				} else if ( helpers === RUNTIME ) {
  					if ( !runtimeHelpers ) {
  						throw new Error( 'Runtime helpers are not enabled. Either exclude the transform-runtime Babel plugin or pass the `runtimeHelpers
  : true` option. See https://github.com/rollup/rollup-plugin-babel#configuring-babel for more information' );
  					}
  				} else {
  					usedHelpers.forEach( function (helper) {
  						if ( inlineHelpers[ helper ] ) {
  							warnOnce( warn, ("The '" + helper + "' Babel helper is used more than once in your code. It's strongly recommended that you
   use the\"external-helpers\" plugin or the \"es2015-rollup\" preset. See https://github.com/rollup/rollup-plugin-babel#configuring-babel for more information") );
  						}
  
  						inlineHelpers[ helper ] = true;
  					});
  				}
  			}
  
  			return {
  				code: transformed.code,
  				map: transformed.map
  			};
  		}
  	};
  }

• example usage

  n/a