systemjs-builder optimizeBuild function spec

gistfile1.js

var entryPoints = {
  entryPoint1Name: 'path/to/entryPoint',
  entryPoint2Name: 'path/to/anoher/entryPoint',
  entryPoint3Name: 'path/to/aThird/entryPoint'
};
/*
Note: entryPoints can also be an array if you are happy to use default bundle names
E.g.
var entryPoints = [
  'path/to/entryPoint',
  'path/to/anoher/entryPoint',
  'path/to/aThird/entryPoint'
];
*/

builder.optimizeBuild(entryPoints, require('custom-optimizer'), {
  // builder-specific options:
  outPath: 'out/folder', // optional, if not set returns source as memory compilation
  sourceMaps: true,
  uglify: true,
  minify: true,
  // etc other options
  // custom configuration options not handled by builder but needed by the optimizer get passed through:
  entrypointPriorities: {},
  // etc...
}).
then(function(optimizedData) {
  console.dir(optimizedData);
/*
{
  bundles: [
    {
      name: 'bundle1Name',
      entryPoint: 'path/to/bundle1/entryPoint', // optional - just for reference, some bundles may not be for a specific entry point and the bundle can still be created without this
      modules: ['path/to/dependency1','path/to/dependency2'], // modules in this bundle
      source: '...' // provided if in memory mode and no outPath given
    },
    ...
  ],
  config: {
    depCache: {
      'path/to/bundle1/entryPoint': ['path/to/dependency1','path/to/dependency2']
    },
    bundles: {
      'out/folder/bundle1Name': ['path/to/bundle1/entryPoint','path/to/dependency1','path/to/dependency2']
    }
  }
}
*/
});


/**
 * Optional, user-defined function to process the tree data generated from the entry points
 * @param {{String|String[]}|[String|String[]]} entryPoints Object or array of entry points (strings or arrays of strings)
 * @param {Object} trace Full trace data mapping to the entry points
 * @param {Object} optimizationOptions Custom variables that can be required or optional for this optimization function
 * @return {Promise|{bundleName:Tree, ...} Promise to be resolved with an object of Trees or
 *         an object of Trees, with each tree representing a bundle to be written.
 */
function optimizationFunction(entryPoints, trace, optimizationOptions) {

  // <clever manuipulation of trees happens here>

  return {
    bundles: [{
      name: 'bundle-1', // name of the bundle in the outpath
      entryPoint: 'path/to/entryPoint', // entry point this bundle is for
      modules: ['path/to/module', 'path/to/anotherModules'], // modules in this bundle
      tree: {}, // The tree object generated by builder functions
    },
    ...
    ],
    config: {
      depCache: {
        ...
      },
      bundles: {
        ...
      }
    }
  };

  // Note the bundle names don't have to be used in the returned data structure if the optimization
  // algorithm calls for a different practice. Also, if no names are provided default names should be
  // used here (bundle0, bundle1, bundle2, etc).
}