systemjs-builder

SystemJS Build Tool

Provides a single-file build for SystemJS of mixed-dependency module trees.

Builds ES6 into ES3, CommonJS, AMD and globals into a single file in a way that supports the CSP SystemJS loader as well as circular references.

Example

app.js

import $ from "./jquery";
export var hello = 'es6';

jquery.js

define(function() {
  return 'this is jquery';
});

Will build the module app into a bundle containing both app and jquery defined through System.register calls.

Circular references and bindings in ES6, CommonJS and AMD all behave exactly as they should, including maintaining execution order.

Usage

Install

  npm install systemjs-builder

Basic Use

  var path = require("path");
  var builder = require('systemjs-builder');

  builder.build('myModule', 'outfile.js', {
    config: {
      baseURL: path.resolve('some/folder'),

      // any map config
      map: {
        jquery: 'jquery-1.2.3/jquery'
      },

      // etc. any SystemJS config
    }
  })
  .then(function() {
    console.log('Build complete');
  })
  .catch(function(err) {
    console.log('Build error');
    console.log(err);
  });

Setting Configuration

To load a SystemJS configuration file, containing configure calls like:

System.config({ ... });

Then we can load this config file through the builder:

  var builder = require('systemjs-builder');

  // `builder.loadConfig` will load config from a file
  builder.loadConfig('./cfg.js')
  .then(function() {
    // additional config can also be set through `builder.config`
    builder.config({ baseURL: 'file:' + process.cwd() });
    
    return builder.build('myModule', 'outfile.js');
  });
  

Multiple config calls can be run, which will combine into the loader configuration.

To reset the loader state and configuration for a new build, run builder.reset().

SFX Bundles

To make a bundle that is independent of the SystemJS loader entirely, we can make SFX bundles:

  var builder = require('systemjs-builder');
  builder.buildSFX('myModule', 'outfile.js', options);

This bundle file can then be included with a <script> tag, and no other dependencies (apart from Traceur runtime if needed) would need to be included in the page.

SFX bundles do not support custom exclusions and inclusions as there is no loader registry.

Rather, if it is needed to have globals like jQuery not included, as they will be separate globals, set up a wrapper module something like:

jquery.js

  module.exports = window.jQuery;

Minfication & Source Maps

As well as an options.config parameter, it is also possible to specify minification and source maps options:

  var builder = require('systemjs-builder');
  builder.build('myModule', 'outfile.js', { minify: true, sourceMaps: true, config: cfg });

Compile time with source maps can also be improved with the lowResSourceMaps option:

  builder.build('myModule', 'outfile.js', { sourceMaps: true, lowResSourceMaps: true });

If you want minification without mangling, you can set the config like this:

  var builder = require('systemjs-builder');
  builder.build('myModule', 'outfile.js', { minify: true, mangle: false });

Ignore Resources

If loading resources that shouldn't even be traced as part of the build (say an external import), these can be configured with:

System.meta['resource/to/ignore'] = {
  build: false
};

Advanced build

The trace trees can be adjusted between tracing and building allowing for custom build layer creation.

Some simple trace tree operators are provided for subtraction addition and intersection.

Tree operations include addTrees, subtractTrees, intersectTrees and extractTree.

Example - Exclusion

In this example we build app/core excluding app/corelibs:

  var builder = require('systemjs-builder');

  builder.config({
    baseURL: '...',
    map: {

    }, // etc. config
  });

  builder.trace('app/main')
  .then(function(appTrace) {
  
    return builder.trace('app/corelibs')
    .then(function(coreTrace) {
      return builder.subtractTrees(appTrace.tree, coreTrace.tree);
    });
  })
  .then(function(appMinusCoreTree) {
    return builder.buildTree(appMinusCoreTree, 'output-file.js');
  });

Example - Common Libraries

In this example we build app/first and app/second creating a separate app/shared library:

  var builder = require('systemjs-builder');

  builder.config({
    // ...
  });

  var firstTree, secondTree, commonTree;

  builder.trace('app/first')
  .then(function(trace) {
    firstTree = trace.tree;
    
    return builder.trace('app/second');
  })
  .then(function(trace) {
    secondTree = trace.tree;
    commonTree = builder.intersectTrees(firstTree, secondTree);

    firstTree = builder.subtractTrees(firstTree, commonTree);
    secondTree = builder.subtractTrees(secondTree, commonTree);

    return builder.buildTree(firstTree, 'first-bundle.js');
  })
  .then(function() {
    return builder.buildTree(secondTree, 'second-bundle.js');
  })
  .then(function() {
    return builder.buildTree(commonTree, 'shared-bundle.js');
  });

License

MIT