From 9403b95417d1f8dff6fec23cb554582568158c12 Mon Sep 17 00:00:00 2001
From: Manuel Mujica <manuel.expat@gmail.com>
Date: Thu, 28 Sep 2017 17:24:28 -0600
Subject: [PATCH] Do not deep clone the graph and loader objects

Closes #855
---
 lib/build/slim.js                   |  1 -
 lib/node/slim/make_shim_template.js |  2 +-
 lib/stream/adjust_bundles_path.js   | 41 +++++++++++++++++++----------
 lib/stream/clone_build_data.js      | 12 ---------
 lib/stream/load_node_builder.js     |  3 +--
 lib/stream/slim.js                  | 15 ++++++++---
 6 files changed, 41 insertions(+), 33 deletions(-)
 delete mode 100644 lib/stream/clone_build_data.js

diff --git a/lib/build/slim.js b/lib/build/slim.js
index 5b7e2b28..c8158723 100644
--- a/lib/build/slim.js
+++ b/lib/build/slim.js
@@ -79,7 +79,6 @@ module.exports = function(cfg, opts) {
 
 		var final = pump(
 			initialStream,
-			cloneBuildData(),
 			adjustBundlesPath({ target: target }), // the "" target is relevant for this transform
 			slimBundles({ target: target || "web" }), // set default target so there is no need to handle ""
 			concat(),
diff --git a/lib/node/slim/make_shim_template.js b/lib/node/slim/make_shim_template.js
index 65263ae5..f9a77686 100644
--- a/lib/node/slim/make_shim_template.js
+++ b/lib/node/slim/make_shim_template.js
@@ -132,7 +132,7 @@ module.exports = function(options) {
 
 			${renderProgressivePartial(options)}
 
-			${options.resolve ? resolveHook.baseResolve : ""};
+			${options.resolve ? resolveHook.baseResolve : ""}
 
 			${options.extensions ? importSlimExtensionsPartial : ""}
 
diff --git a/lib/stream/adjust_bundles_path.js b/lib/stream/adjust_bundles_path.js
index b0327dc1..fdf9043c 100644
--- a/lib/stream/adjust_bundles_path.js
+++ b/lib/stream/adjust_bundles_path.js
@@ -1,29 +1,42 @@
 var through = require("through2");
+var omit = require("lodash/omit");
+var clone = require("lodash/clone");
+var assign = require("lodash/assign");
 
 module.exports = function(options) {
 	return through.obj(function(data, enc, next) {
 		try {
-			next(null, adjustBundlesPath(data, options));
+			next(null, options.target ? adjustBundlesPath(data, options) : data);
 		} catch (err) {
 			next(err);
 		}
 	});
 };
 
+/**
+ * Appends the target name to the bundles path
+ *
+ * Each target build should be written in its own subfolder, e.g:
+ *
+ *	dist/bundles/node
+ *	dist/bundles/web
+ *	dist/bundles/worker
+ *
+ * This should only happen when target is explicitly set.
+ */
 function adjustBundlesPath(data, options) {
-	if (options.target) {
-		var path = require("path");
+	var path = require("path");
+	var configuration = clone(data.configuration);
 
-		// override the configuration getter for `bundlesPath` so it
-		// includes the target name
-		var bundlesPath = data.configuration.bundlesPath;
-		Object.defineProperty(data.configuration, "bundlesPath", {
-			configurable: true,
-			get: function() {
-				return path.join(bundlesPath, options.target);
-			}
-		});
-	}
+	var bundlesPath = configuration.bundlesPath;
+	Object.defineProperty(configuration, "bundlesPath", {
+		configurable: true,
+		get: function() {
+			return path.join(bundlesPath, options.target);
+		}
+	});
 
-	return data;
+	return assign({}, omit(data, ["configuration"]), {
+		configuration: configuration
+	});
 }
diff --git a/lib/stream/clone_build_data.js b/lib/stream/clone_build_data.js
deleted file mode 100644
index b3f056de..00000000
--- a/lib/stream/clone_build_data.js
+++ /dev/null
@@ -1,12 +0,0 @@
-var through = require("through2");
-var clone = require("lodash/cloneDeep");
-
-module.exports = function() {
-	return through.obj(function(data, enc, next) {
-		try {
-			next(null, clone(data));
-		} catch (err) {
-			next(err);
-		}
-	});
-};
diff --git a/lib/stream/load_node_builder.js b/lib/stream/load_node_builder.js
index cafaf555..0642b6d7 100644
--- a/lib/stream/load_node_builder.js
+++ b/lib/stream/load_node_builder.js
@@ -1,7 +1,6 @@
 var keys = require("lodash/keys");
 var through = require("through2");
 var assign = require("lodash/assign");
-var cloneDeep = require("lodash/cloneDeep");
 
 module.exports = function() {
 	return through.obj(function(data, enc, next) {
@@ -20,8 +19,8 @@ module.exports = function() {
  */
 function loadNodeBuilder(data) {
 	return new Promise(function(resolve, reject) {
+		var graph = data.graph;
 		var loader = data.loader;
-		var graph = cloneDeep(data.graph);
 
 		var promises = keys(graph).map(function(nodeName) {
 			var node = graph[nodeName];
diff --git a/lib/stream/slim.js b/lib/stream/slim.js
index 7cdf2546..eed1fa43 100644
--- a/lib/stream/slim.js
+++ b/lib/stream/slim.js
@@ -1,4 +1,7 @@
+var omit = require("lodash/omit");
 var through = require("through2");
+var assign = require("lodash/assign");
+var cloneDeep = require("lodash/cloneDeep");
 var slimGraph = require("../graph/slim_graph");
 
 /**
@@ -23,10 +26,12 @@ module.exports = function(options) {
  * @return {Object} The mutated data
  */
 function doSlimGrap(data, options) {
-	data.bundles = slimGraph({
+	var bundles = cloneDeep(data.bundles);
+
+	var slimmedBundles = slimGraph({
 		graph: data.graph,
 		mains: data.mains,
-		bundles: data.bundles,
+		bundles: bundles,
 		target: options.target,
 		baseUrl: data.loader.baseURL,
 		slimConfig: data.loader.slimConfig,
@@ -36,7 +41,11 @@ function doSlimGrap(data, options) {
 		progressiveBundles: getProgressiveBundles(data.loader, data.graph)
 	});
 
-	return data;
+	return assign(
+		{},
+		omit(data, ["bundles"]),
+		{ bundles: slimmedBundles }
+	);
 }