Stabilize and align Intersection Observers

- Fixes several crashes
- Aligns the feature with the W3C WD spec

Tag #249

1 files changed, 39 insertions, 20 deletions

diff --git a/dom/base/test/test_intersectionobservers.html b/dom/base/test/test_intersectionobservers.html
index e7875e3af..10e3d7712 100644
--- a/dom/base/test/test_intersectionobservers.html
+++ b/dom/base/test/test_intersectionobservers.html
@@ -325,7 +325,7 @@ limitations under the License.
       });
 
 
-      it('does not trigger if target does not intersect when observing begins',
+      it('does trigger if target does not intersect when observing begins',
           function(done) {
 
         var spy = sinon.spy();
@@ -334,7 +334,7 @@ limitations under the License.
         targetEl2.style.top = '-40px';
         io.observe(targetEl2);
         callDelayed(function() {
-          expect(spy.callCount).to.be(0);
+          expect(spy.callCount).to.be(1);
           done();
         }, ASYNC_TIMEOUT);
       });
@@ -528,7 +528,7 @@ limitations under the License.
             spy.waitForNotification(function() {
               expect(spy.callCount).to.be(1);
               var records = sortRecords(spy.lastCall.args[0]);
-              expect(records.length).to.be(2);
+              expect(records.length).to.be(3);
               expect(records[0].target).to.be(targetEl1);
               expect(records[0].intersectionRatio).to.be(0.25);
               expect(records[1].target).to.be(targetEl2);
@@ -636,10 +636,10 @@ limitations under the License.
               expect(records.length).to.be(3);
               expect(records[0].target).to.be(targetEl1);
               expect(records[0].intersectionRatio).to.be(0.5);
-              expect(records[1].target).to.be(targetEl3);
-              expect(records[1].intersectionRatio).to.be(0.5);
-              expect(records[2].target).to.be(targetEl4);
+              expect(records[2].target).to.be(targetEl3);
               expect(records[2].intersectionRatio).to.be(0.5);
+              expect(records[3].target).to.be(targetEl4);
+              expect(records[3].intersectionRatio).to.be(0.5);
               io.disconnect();
               done();
             }, {root: rootEl, rootMargin: '-10px 10%'});
@@ -652,11 +652,11 @@ limitations under the License.
           function(done) {
             io = new IntersectionObserver(function(records) {
               records = sortRecords(records);
-              expect(records.length).to.be(2);
+              expect(records.length).to.be(4);
               expect(records[0].target).to.be(targetEl1);
               expect(records[0].intersectionRatio).to.be(0.5);
-              expect(records[1].target).to.be(targetEl4);
-              expect(records[1].intersectionRatio).to.be(0.5);
+              expect(records[3].target).to.be(targetEl4);
+              expect(records[3].intersectionRatio).to.be(0.5);
               io.disconnect();
               done();
             }, {root: rootEl, rootMargin: '-5% -2.5% 0px'});
@@ -669,13 +669,13 @@ limitations under the License.
           function(done) {
             io = new IntersectionObserver(function(records) {
               records = sortRecords(records);
-              expect(records.length).to.be(3);
+              expect(records.length).to.be(4);
               expect(records[0].target).to.be(targetEl1);
               expect(records[0].intersectionRatio).to.be(0.5);
               expect(records[1].target).to.be(targetEl2);
               expect(records[1].intersectionRatio).to.be(0.5);
-              expect(records[2].target).to.be(targetEl4);
-              expect(records[2].intersectionRatio).to.be(0.25);
+              expect(records[3].target).to.be(targetEl4);
+              expect(records[3].intersectionRatio).to.be(0.25);
               io.disconnect();
               done();
             }, {root: rootEl, rootMargin: '5% -2.5% -10px -190px'});
@@ -705,9 +705,9 @@ limitations under the License.
             spy.waitForNotification(function() {
               expect(spy.callCount).to.be(1);
               var records = sortRecords(spy.lastCall.args[0]);
-              expect(records.length).to.be(1);
-              expect(records[0].intersectionRatio).to.be(0);
-              expect(records[0].target).to.be(targetEl2);
+              expect(records.length).to.be(2);
+              expect(records[1].intersectionRatio).to.be(0);
+              expect(records[1].target).to.be(targetEl2);
               done();
             }, ASYNC_TIMEOUT);
           },
@@ -797,14 +797,14 @@ limitations under the License.
           function(done) {
             document.getElementById('fixtures').appendChild(rootEl);
             callDelayed(function() {
-              expect(spy.callCount).to.be(0);
+              expect(spy.callCount).to.be(1);
               done();
             }, ASYNC_TIMEOUT);
           },
           function(done) {
             parentEl.insertBefore(targetEl1, targetEl2);
             spy.waitForNotification(function() {
-              expect(spy.callCount).to.be(1);
+              expect(spy.callCount).to.be(2);
               var records = sortRecords(spy.lastCall.args[0]);
               expect(records.length).to.be(1);
               expect(records[0].intersectionRatio).to.be(1);
@@ -815,7 +815,7 @@ limitations under the License.
           function(done) {
             grandParentEl.parentNode.removeChild(grandParentEl);
             spy.waitForNotification(function() {
-              expect(spy.callCount).to.be(2);
+              expect(spy.callCount).to.be(3);
               var records = sortRecords(spy.lastCall.args[0]);
               expect(records.length).to.be(1);
               expect(records[0].intersectionRatio).to.be(0);
@@ -826,7 +826,7 @@ limitations under the License.
           function(done) {
             rootEl.appendChild(targetEl1);
             spy.waitForNotification(function() {
-              expect(spy.callCount).to.be(3);
+              expect(spy.callCount).to.be(4);
               var records = sortRecords(spy.lastCall.args[0]);
               expect(records.length).to.be(1);
               expect(records[0].intersectionRatio).to.be(1);
@@ -837,7 +837,7 @@ limitations under the License.
           function(done) {
             rootEl.parentNode.removeChild(rootEl);
             spy.waitForNotification(function() {
-              expect(spy.callCount).to.be(4);
+              expect(spy.callCount).to.be(5);
               var records = sortRecords(spy.lastCall.args[0]);
               expect(records.length).to.be(1);
               expect(records[0].intersectionRatio).to.be(0);
@@ -867,8 +867,14 @@ limitations under the License.
 
         targetEl1.style.top = '220px';
         targetEl1.style.left = '220px';
+        
+        var callCount = 0;
 
         io = new IntersectionObserver(function(records) {
+          callCount++;
+          if (callCount <= 1) {
+            return;
+          }
           expect(records.length).to.be(1);
           expect(records[0].intersectionRatio).to.be(1);
           done();
@@ -891,6 +897,19 @@ limitations under the License.
         var win = window.open("intersectionobserver_window.html");
       });
 
+      it('triggers only once if observed multiple times (and does not crash when collected)', function(done) {
+        var spy = sinon.spy();
+        io = new IntersectionObserver(spy, {root: rootEl});
+        io.observe(targetEl1);
+        io.observe(targetEl1);
+        io.observe(targetEl1);
+
+        callDelayed(function () {
+          expect(spy.callCount).to.be(1);
+          done();
+        }, ASYNC_TIMEOUT);
+      });
+
     });
 
     describe('observe subframe', function () {