enhancement in development:

1. manage config files in one file
2. move scrollama.js from dev to build, just to keep it DRY
3. use uglify in rollup
4. add rollup-plugin-filesize so that we can notify the size of every building
5. use cross-env to avoid building crash in windows

build/scrollama.js

@@ -7,17 +7,10 @@
 /**
  * Copyright 2016 Google Inc. All Rights Reserved.
  *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
+ * Licensed under the W3C SOFTWARE AND DOCUMENT NOTICE AND LICENSE.
  *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
+ *  https://www.w3.org/Consortium/Legal/2015/copyright-software-and-document
+ * 
  */
 
 (function(window, document) {
@@ -31,7 +24,7 @@ if ('IntersectionObserver' in window &&
     'intersectionRatio' in window.IntersectionObserverEntry.prototype) {
 
   // Minimal polyfill for Edge 15's lack of `isIntersecting`
-  // See: https://github.com/WICG/IntersectionObserver/issues/211
+  // See: https://github.com/w3c/IntersectionObserver/issues/211
   if (!('isIntersecting' in window.IntersectionObserverEntry.prototype)) {
     Object.defineProperty(window.IntersectionObserverEntry.prototype,
       'isIntersecting', {
@@ -55,7 +48,7 @@ var registry = [];
 
 /**
  * Creates the global IntersectionObserverEntry constructor.
- * https://wicg.github.io/IntersectionObserver/#intersection-observer-entry
+ * https://w3c.github.io/IntersectionObserver/#intersection-observer-entry
  * @param {Object} entry A dictionary of instance properties.
  * @constructor
  */
@@ -85,7 +78,7 @@ function IntersectionObserverEntry(entry) {
 
 /**
  * Creates the global IntersectionObserver constructor.
- * https://wicg.github.io/IntersectionObserver/#intersection-observer-interface
+ * https://w3c.github.io/IntersectionObserver/#intersection-observer-interface
  * @param {Function} callback The function to be invoked after intersection
  *     changes have queued. The function is not invoked if the queue has
  *     been emptied by calling the `takeRecords` method.
@@ -363,7 +356,7 @@ IntersectionObserver.prototype._checkForIntersections = function() {
  * Accepts a target and root rect computes the intersection between then
  * following the algorithm in the spec.
  * TODO(philipwalton): at this time clip-path is not considered.
- * https://wicg.github.io/IntersectionObserver/#calculate-intersection-rect-algo
+ * https://w3c.github.io/IntersectionObserver/#calculate-intersection-rect-algo
  * @param {Element} target The target DOM element
  * @param {Object} rootRect The bounding rect of the root after being
  *     expanded by the rootMargin value.
@@ -656,7 +649,7 @@ function getBoundingClientRect(el) {
     rect = el.getBoundingClientRect();
   } catch (err) {
     // Ignore Windows 7 IE11 "Unspecified error"
-    // https://github.com/WICG/IntersectionObserver/pull/205
+    // https://github.com/w3c/IntersectionObserver/pull/205
   }
 
   if (!rect) { return getEmptyRect(); }

dev/index.html

@@ -105,7 +105,7 @@
 	</section>
 	<div class='debug'></div>
 	<script src='d3.v4.min.js'></script>
-	<script src='scrollama.js'></script>
+	<script src='../build/scrollama.js'></script>
 	<script>
 		var container = d3.select('#scroll')
 		var graphic = container.select('.scroll__graphic')
@@ -183,4 +183,4 @@
 	</script>
 </body>
 
-</html>
+</html>