behavior: Turn scroll JS code into class

2 files changed, 33 insertions, 27 deletions

diff --git a/crocoite/behavior.py b/crocoite/behavior.py
index d5c82a0..5f66538 100644
--- a/crocoite/behavior.py
+++ b/crocoite/behavior.py
@@ -120,9 +120,10 @@ class JsOnload (Behavior):
         tab = self.loader.tab
         yield self.script
         result = await tab.Runtime.evaluate (expression=str (self.script))
+        exception = result.get ('exceptionDetails', None)
         result = result['result']
         assert result['type'] == 'object'
-        assert result.get ('subtype') != 'error'
+        assert result.get ('subtype') != 'error', exception
         self.context = result['objectId']
 
     async def onstop (self):
diff --git a/crocoite/data/scroll.js b/crocoite/data/scroll.js
index 8a4b35d..aacfe83 100644
--- a/crocoite/data/scroll.js
+++ b/crocoite/data/scroll.js
@@ -1,33 +1,38 @@
 /*	Continuously scrolls the page
  */
 (function(){
-let scrolled = new Map ();
-let interval = null;
-function stop() {
-	window.clearInterval (interval);
-	window.scrollTo (0, 0);
-	scrolled.forEach (function (value, key, map) {
-		key.scrollTop = value;
-	});
-}
-/* save initial scroll state */
-function save(obj) {
-	if (!scrolled.has (obj)) {
-		scrolled.set (obj, obj.scrollTop);
+class Scroll {
+	constructor () {
+		this.scrolled = new Map ();
+		this.interval = window.setInterval (this.scroll.bind (this), 200);
 	}
-}
-/* perform a single scroll step */
-function scroll (event) {
-	window.scrollBy (0, window.innerHeight/2);
-	document.querySelectorAll ('html body *').forEach (
-		function (d) {
-			if (d.scrollHeight-d.scrollTop > d.clientHeight) {
-				save (d);
-				d.scrollBy (0, d.clientHeight/2);
-			}
+
+	stop() {
+		window.clearInterval (this.interval);
+		window.scrollTo (0, 0);
+		this.scrolled.forEach (function (value, key, map) {
+			key.scrollTop = value;
 		});
-	return true;
+	}
+	/* save initial scroll state */
+	save(obj) {
+		if (!this.scrolled.has (obj)) {
+			this.scrolled.set (obj, obj.scrollTop);
+		}
+	}
+	/* perform a single scroll step */
+	scroll (event) {
+		window.scrollBy (0, window.innerHeight/2);
+		document.querySelectorAll ('html body *').forEach (
+			function (d) {
+				if (d.scrollHeight-d.scrollTop > d.clientHeight) {
+					this.save (d);
+					d.scrollBy (0, d.clientHeight/2);
+				}
+			}.bind (this));
+		return true;
+	}
 }
-interval = window.setInterval (scroll, 200);
-return {'stop': stop};
+
+return new Scroll();
 }())