AutoXHR: Do not extend the event timeout with each uninteresting muta…

…tion

plugins/auto-xhr.js

@@ -987,9 +987,10 @@
 			});
 		}
 
-		if (!evt.interesting) {
-			// if we didn't have any interesting nodes for this MO callback or
-			// any prior callbacks, timeout the event
+		if (!this.timer && !evt.interesting) {
+			// timeout the event if we haven't already created a timer and
+			// we didn't have any interesting nodes for this MO callback or
+			// any prior callbacks
 			this.setTimeout(SPA_TIMEOUT, index);
 		}
 
@@ -1477,7 +1478,8 @@
 	 * - We turn on DOM observer, and wait up to 50 milliseconds for something
 	 *  - If nothing happens after the timeout, we stop watching and clear the resource without firing the event
 	 *  - If a history event happened recently/will happen shortly, use the URL as the resource.url
-	 *  - Else if something uninteresting happens, we extend the timeout for 1 second
+	 *  - Else if something uninteresting happens, we set the timeout for 1 second if it wasn't already started
+	 *    - We don't want to continuously extend the timeout with each uninteresting event
 	 *  - Else if an interesting node is added, we add load and error listeners and turn off the timeout but keep watching
 	 *    - If we do not have a resource.url, and if this is a script, then we use the script's URL
 	 *    - Once all listeners have fired, we stop watching, fire the event and clear the resource
@@ -1490,7 +1492,8 @@
 	 * - If a history event happened recently/will happen shortly, use the URL as the resource.url
 	 * - We watch for all changes in state (for async requests) and for load (for all requests)
 	 * - On load, we turn on DOM observer, and wait up to 50 milliseconds for something
-	 *  - If something uninteresting happens, we extend the timeout for 1 second
+	 *  - If something uninteresting happens, we set the timeout for 1 second if it wasn't already started
+	 *    - We don't want to continuously extend the timeout with each uninteresting event
 	 *  - Else if an interesting node is added, we add load and error listeners and turn off the timeout
 	 *    - Once all listeners have fired, we stop watching, fire the event and clear the resource
 	 *  - If nothing happens after the timeout, we stop watching fire the event and clear the resource

tests/page-templates/07-autoxhr/38-xhr-uninteresting-mo.html

@@ -0,0 +1,77 @@
+<%= header %>
+<!--
+Verify that creating uninteresting mutation observer events doesn't hold an xhr beacon from being sent
+-->
+<script src="38-xhr-uninteresting-mo.js" type="text/javascript"></script>
+<%= boomerangSnippet %>
+<script>
+// create non interesting MO events a few times per second
+function addDiv() {
+	var div = window.document.createElement("div");
+	window.document.body.appendChild(div);
+	setTimeout(addDiv, 200);
+};
+setTimeout(addDiv, 200);
+
+BOOMR_test.init({
+	"instrument_xhr": true,
+	afterFirstBeacon:
+		function() {
+			if (!BOOMR.plugins.AutoXHR) {
+				return;
+			}
+
+			var xhrNum = 0;
+			function sendBeacon() {
+				setTimeout(function() {
+					var xhr;
+					if (xhrNum === 0) {
+						xhr = new XMLHttpRequest();
+						xhr.open("GET", "support/script200.js"); //200, async
+						xhr.send(null);
+					}
+					else if (xhrNum === 1) {
+						xhr = new XMLHttpRequest();
+						xhr.open("GET", "support/script200.js", false); //200, sync
+						xhr.send(null);
+					}
+					else if (xhrNum === 2) {
+						xhr = new XMLHttpRequest();
+						xhr.open("GET", "support/script404.js"); //404, async
+						xhr.send(null);
+					}
+					else if (xhrNum === 3) {
+						xhr = new XMLHttpRequest();
+						xhr.open("GET", "support/script404.js", false); //404, sync
+						xhr.send(null);
+					}
+					else if (xhrNum === 4) {
+						xhr = new XMLHttpRequest();
+						xhr.open("GET", "http://soasta.com"); //error
+						xhr.send(null);
+					}
+					else if (xhrNum === 5) {
+						xhr = new XMLHttpRequest();
+						xhr.open("GET", "support/script200.js"); //200, async, abort
+						xhr.send(null);
+						xhr.abort();
+					}
+					else if (xhrNum === 6) {
+						xhr = new XMLHttpRequest();
+						xhr.open("GET", "support/script200.js"); //200, async, timeout
+						xhr.timeout = 1;
+						xhr.send(null);
+					}
+					xhrNum++;
+				}, 100);
+			}
+
+			// send a new XHR on each beacon
+			BOOMR.subscribe("onbeacon", sendBeacon);
+
+			// start the first beacon
+			sendBeacon();
+		}
+});
+</script>
+<%= footer %>

tests/page-templates/07-autoxhr/38-xhr-uninteresting-mo.js

@@ -0,0 +1,115 @@
+/*eslint-env mocha*/
+/*global assert*/
+
+describe("e2e/07-autoxhr/38-xhr-uninteresting-mo", function() {
+	var t = BOOMR_test;
+	var tf = BOOMR.plugins.TestFramework;
+
+	it("Should get 8 beacons: 1 onload, 7 xhr (XMLHttpRequest !== null)", function(done) {
+		this.timeout(10000);
+		t.ifAutoXHR(
+			done,
+			function() {
+				t.ensureBeaconCount(done, 8);
+			});
+	});
+
+	it("Should get 8 beacons: 1st onload beacon (XMLHttpRequest !== null)", function(done) {
+		t.ifAutoXHR(
+			done,
+			function() {
+				assert.include(tf.beacons[0].u, "38-xhr-uninteresting-mo.html");
+				done();
+			});
+	});
+
+	it("Should get 8 beacons: 2nd XHR 200 async beacon (XMLHttpRequest !== null)", function(done) {
+		t.ifAutoXHR(
+			done,
+			function() {
+				assert.include(tf.beacons[1].u, "script200.js");
+				done();
+			});
+	});
+
+	it("Should get 8 beacons: 3rd XHR 200 sync beacon (XMLHttpRequest !== null)", function(done) {
+		t.ifAutoXHR(
+			done,
+			function() {
+				assert.include(tf.beacons[2].u, "script200.js");
+				done();
+			});
+	});
+
+	it("Should get 8 beacons: 4th XHR 404 async beacon (XMLHttpRequest !== null)", function(done) {
+		t.ifAutoXHR(
+			done,
+			function() {
+				assert.include(tf.beacons[3].u, "script404.js");
+				done();
+			});
+	});
+
+	it("Should get 8 beacons: 5th XHR 404 sync beacon (XMLHttpRequest !== null)", function(done) {
+		t.ifAutoXHR(
+			done,
+			function() {
+				assert.include(tf.beacons[4].u, "script404.js");
+				done();
+			});
+	});
+
+	it("Should get 8 beacons: 6th X-O beacon (XMLHttpRequest !== null)", function(done) {
+		t.ifAutoXHR(
+			done,
+			function() {
+				assert.include(tf.beacons[5].u, "soasta.com");
+				done();
+			});
+	});
+
+	it("Should get 8 beacons: 7th abort beacon (XMLHttpRequest !== null)", function(done) {
+		t.ifAutoXHR(
+			done,
+			function() {
+				assert.include(tf.beacons[6].u, "script200.js");
+				done();
+			});
+	});
+
+	it("Should get 8 beacons: 8th timeout beacon (XMLHttpRequest !== null)", function(done) {
+		t.ifAutoXHR(
+			done,
+			function() {
+				assert.include(tf.beacons[7].u, "script200.js");
+				done();
+			});
+	});
+
+	it("Should get 1 beacons: 1 onload, 0 xhr (XMLHttpRequest === null)", function(done) {
+		t.ifAutoXHR(
+			done,
+			undefined,
+			function() {
+				t.ensureBeaconCount(done, 1);
+			});
+	});
+
+	it("Should have all beacons set rt.nstart = navigationTiming (if NavigationTiming is supported)", function(done) {
+		t.ifAutoXHR(
+			done,
+			undefined,
+			function() {
+				if (typeof BOOMR.plugins.RT.navigationStart() !== "undefined") {
+					for (var i = 0; i <= 7; i++) {
+						assert.equal(tf.beacons[i]["rt.nstart"], BOOMR.plugins.RT.navigationStart());
+					}
+				}
+				else {
+					done();
+				}
+			}
+		);
+	});
+
+});