1 files changed, 128 insertions, 0 deletions
diff --git a/testing/web-platform/tests/css/css-scroll-snap/snap-after-relayout/multiple-aligned-targets/prefer-focused-element.html b/testing/web-platform/tests/css/css-scroll-snap/snap-after-relayout/multiple-aligned-targets/prefer-focused-element.html
new file mode 100644
index 0000000000..f15a291f08
--- /dev/null
+++ b/testing/web-platform/tests/css/css-scroll-snap/snap-after-relayout/multiple-aligned-targets/prefer-focused-element.html
@@ -0,0 +1,128 @@
+<!DOCTYPE html>
+<html>
+  <head>
+    <link rel="help" href="https://drafts.csswg.org/css-scroll-snap" />
+    <script src="/resources/testharness.js"></script>
+    <script src="/resources/testharnessreport.js"></script>
+    <script src="/dom/events/scrolling/scroll_support.js"></script>
+    <script src="/resources/testdriver.js"></script>
+    <script src="/resources/testdriver-actions.js"></script>
+    <script src="/resources/testdriver-vendor.js"></script>
+    <script src="resources/common.js" ></script>
+  </head>
+  <body>
+    <style>
+      .scroller {
+        overflow: scroll;
+        position: relative;
+        height: 400px;
+        width: 400px;
+        border:solid 1px black;
+        scroll-snap-type: y mandatory;
+      }
+      .no-snap { scroll-snap-align: none }
+      .scroller div:focus {
+        border: solid 1px red;
+      }
+      .large-space {
+        height: 300vh;
+        width: 300vw;
+      }
+      .target {
+        scroll-snap-align: start;
+        position: absolute;
+        width: 100px;
+        height: 100px;
+        border: solid 1px black;
+      }
+      .top {
+        top: 0px;
+      }
+      .left {
+        left: 0px;
+      }
+      .right {
+        left: 200px;
+      }
+      .bottom {
+        top: 200px;
+      }
+      </style>
+    <div id="scroller" class="scroller">
+      <div class="large-space no-snap" tabindex="1" id="space"></div>
+      <div id="topleft" tabindex="1" class="top left target">top left</div>
+      <div id="topright" tabindex="1" class="top right target">top right</div>
+      <div id="bottomleft" tabindex="1" class="bottom left target">bottom left</div>
+      <div id="bottomright" tabindex="1" class="bottom right target">bottom right</div>
+    </div>
+    <script>
+      window.onload = () => {
+        const bottomright = document.getElementById("bottomright");
+        const bottomleft = document.getElementById("bottomleft");
+        const scroller = document.getElementById("scroller");
+
+        async function commonInitialization() {
+          await waitForCompositorCommit();
+          assert_equals(scroller.scrollTop, 0, "snapped to top row");
+        }
+
+        promise_test(async (t) => {
+          await commonInitialization();
+
+          focusAndAssert(bottomright);
+          await runScrollSnapSelectionVerificationTest(t, scroller,
+                                                       [bottomright,
+                                                        bottomleft],
+                                    /*expected_target=*/bottomright, "y");
+
+          focusAndAssert(bottomleft);
+          await runScrollSnapSelectionVerificationTest(t, scroller,
+                                                       [bottomright,
+                                                        bottomleft],
+                                    /*expected_target=*/bottomleft, "y");
+        }, "scroller selects focused target from aligned choices on snap");
+
+        promise_test(async (t) => {
+          t.add_cleanup(() => {
+            bottomright.style.left = "200px";
+          })
+          await commonInitialization();
+
+          // Move bottomright out of the snapport.
+          bottomright.style.left = "500px";
+
+          // Set focus on bottomright without scrolling to it.
+          focusAndAssert(bottomright, true);
+          await runScrollSnapSelectionVerificationTest(t, scroller,
+                                                       [bottomright,
+                                                        bottomleft],
+                                    /*expected_target=*/bottomleft, "y");
+        }, "out-of-viewport focused element is not the selected snap target.");
+
+        promise_test(async(t) => {
+          t.add_cleanup(() => {
+            bottomleft.style.top = "200px";
+          });
+          await commonInitialization();
+
+          // Set focus on bottomright without scrolling to it.
+          focusAndAssert(bottomright, true);
+
+          // Move bottomleft below bottomright.
+          bottomleft.style.top = "400px";
+
+          // Snap to bottomleft.
+          scroller.scrollTop = bottomleft.offsetTop;
+
+          // Test that if bottomright is also shifted so that it is aligned with
+          // bottomleft, bottomleft remains the selected snap target, despite
+          // bottomright's having focus.
+          await runLayoutSnapSeletionVerificationTest(t, scroller, [bottomright],
+                                                bottomleft, "y");
+        }, "scroller follows selected snap target through layout shift," +
+           "regardless of focus");
+
+      }
+    </script>
+  </body>
+</html>