1 files changed, 40 insertions, 0 deletions
diff --git a/tests/wpt/web-platform-tests/web-animations/keyframe-effect/keyframe-handling.html b/tests/wpt/web-platform-tests/web-animations/keyframe-effect/keyframe-handling.html
index 56f484aff7f..de9b7c7ec21 100644
--- a/tests/wpt/web-platform-tests/web-animations/keyframe-effect/keyframe-handling.html
+++ b/tests/wpt/web-platform-tests/web-animations/keyframe-effect/keyframe-handling.html
@@ -70,6 +70,46 @@ test(function(t) {
 }, 'Overlapping keyframes between 0 and 1 use the appropriate value on each'
    + ' side of the overlap point');
 
+test(function(t) {
+  var div = createDiv(t);
+  var anim = div.animate({ visibility: ['hidden','visible'] },
+                         { duration: 100 * MS_PER_SEC, fill: 'both' });
+
+  anim.currentTime = 0;
+  assert_equals(getComputedStyle(div).visibility, 'hidden',
+                'Visibility when progress = 0.');
+
+  anim.currentTime = 10 * MS_PER_SEC + 1;
+  assert_equals(getComputedStyle(div).visibility, 'visible',
+                'Visibility when progress > 0 due to linear easing.');
+
+  anim.finish();
+  assert_equals(getComputedStyle(div).visibility, 'visible',
+                'Visibility when progress = 1.');
+
+}, "Test visibility clamping behavior.");
+
+test(function(t) {
+  var div = createDiv(t);
+  var anim = div.animate({ visibility: ['hidden', 'visible'] },
+                         { duration: 100 * MS_PER_SEC, fill: 'both',
+                           easing: 'cubic-bezier(0.25, -0.6, 0, 0.5)' });
+
+  anim.currentTime = 0;
+  assert_equals(getComputedStyle(div).visibility, 'hidden',
+                'Visibility when progress = 0.');
+
+  // Timing function is below zero. So we expected visibility is hidden.
+  anim.currentTime = 10 * MS_PER_SEC + 1;
+  assert_equals(getComputedStyle(div).visibility, 'hidden',
+                'Visibility when progress < 0 due to cubic-bezier easing.');
+
+  anim.currentTime = 60 * MS_PER_SEC;
+  assert_equals(getComputedStyle(div).visibility, 'visible',
+                'Visibility when progress > 0 due to cubic-bezier easing.');
+
+}, "Test visibility clamping behavior with an easing that has a negative component");
+
 done();
 </script>
 </body>