steal-tools/lib/bundle/write_bundles.js

Futuristic build tools for ES6 Module applications.

// # lib/bundle/write_bundles.js
// Given an array of bundles and the baseURL
// Writes them out to the file system.

var winston = require('winston');
var bundleFilename = require("./filename"),
	concatSource = require("../bundle/concat_source"),
	normalizeSource = require('./normalize_source'),
	fs = require("fs"),
	mkdirp = require("fs-extra").mkdirp,
	dirname = require("path").dirname,
	addSourceMapUrl = require("../bundle/add_source_map_url"),
	through = require("through2");

var writeBundles = module.exports = function(bundles, configuration) {
  var bundlesDir = configuration.bundlesPath + "/";
  // Create the bundle directory
  var bundleDirDef = configuration.mkBundlesPathDir();

  // A deferred containing a deferred that resolves when all
  // deferreds have been built.
  var builtBundleDeferreds = [];

  bundles.forEach(function(bundle) {
    builtBundleDeferreds.push(new Promise(function(resolve, reject) {
      var bundlePath = bundlesDir + "" + bundleFilename(bundle);

	  // If the bundle is explicity marked as clean, just resolve.
	  if(bundle.isDirty === false) {
		return resolve(bundle);
	  }

      // Adjusts URLs
      normalizeSource(bundle, bundlePath);

      // Combines the source
      concatSource(bundle);

	  var code = bundle.source.code, map;
	  if(configuration.options.sourceMaps) {
		  addSourceMapUrl(bundle);
		  code = bundle.source.code;
		  map = bundle.source.map;
	  }

      // Log the bundles
      winston.info("BUNDLE: %s", bundleFilename(bundle));
      winston.debug(Buffer.byteLength(code, "utf8") + " bytes");

      bundle.nodes.forEach(function(node) {
        winston.info("+ %s", node.load.name);
      });

      // Once a folder has been created, write out the bundle source
      bundleDirDef.then(function() {
        mkdirp(dirname(bundlePath), function(err) {
          if (err) {
            reject(err);
          }
          else {
            fs.writeFile(bundlePath, code, function(err) {
              if(err) {
                reject(err);
              } else {
                if(!map) {
                  resolve(bundle);
				  return;
                }
                // Write out the source map
                fs.writeFile(bundlePath+".map", map, function(err) {
                  if(err) return reject(err);
                  resolve(bundle);
                });
              }
            });
          }
        });

      }).catch(function(err) {
        reject(err);
      });
    }));

  });

  return Promise.all(builtBundleDeferreds);

};

writeBundles.createWriteStream = function(){
	function write(buildResult, enc, done) {
		var configuration = buildResult.configuration;
		var bundles = buildResult.bundles;

		writeBundles(bundles, configuration).then(function(){
			done(null, buildResult);
		}, done);
	}

	return through.obj(write);
};