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diff --git a/testing/web-platform/tests/css/css-masking/animations/clip-interpolation.html b/testing/web-platform/tests/css/css-masking/animations/clip-interpolation.html
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+++ b/testing/web-platform/tests/css/css-masking/animations/clip-interpolation.html
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+<!DOCTYPE html>
+<meta charset="UTF-8">
+<title>clip interpolation</title>
+<link rel="help" href="https://drafts.fxtf.org/css-masking-1/#clip-property">
+<meta name="assert" content="clip supports animation">
+
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/css/support/interpolation-testcommon.js"></script>
+
+<style>
+.container {
+  width: 80px;
+  height: 80px;
+  background: black;
+  display: inline-block;
+  padding: 5px;
+}
+
+.container:nth-child(2n) {
+  background: green;
+}
+
+.parent {
+  clip: rect(100px, 0px, 100px, 0px);
+}
+
+.target {
+  width: 80px;
+  height: 80px;
+  display: inline-block;
+  position: absolute;
+  background: white;
+  clip: rect(0px, 100px, 0px, 100px);
+}
+</style>
+
+<body>
+<template id="target-template">
+<div class="container"><div class="target"></div></div>
+</template>
+<script>
+test_interpolation({
+  property: 'clip',
+  from: neutralKeyframe,
+  to: 'rect(20px, 20px, 20px, 20px)',
+}, [
+  {at: -1, expect: 'rect(-20px 180px -20px 180px)'},
+  {at: 0, expect: 'rect(0px 100px 0px 100px)'},
+  {at: 0.25, expect: 'rect(5px 80px 5px 80px)'},
+  {at: 0.75, expect: 'rect(15px 40px 15px 40px)'},
+  {at: 1, expect: 'rect(20px 20px 20px 20px)'},
+  {at: 2, expect: 'rect(40px -60px 40px -60px)'},
+]);
+
+test_no_interpolation({
+  property: 'clip',
+  from: 'initial',
+  to: 'rect(20px, 20px, 20px, 20px)',
+});
+
+test_interpolation({
+  property: 'clip',
+  from: 'inherit',
+  to: 'rect(20px, 20px, 20px, 20px)',
+}, [
+  {at: -1, expect: 'rect(180px -20px 180px -20px)'},
+  {at: 0, expect: 'rect(100px 0px 100px 0px)'},
+  {at: 0.25, expect: 'rect(80px 5px 80px 5px)'},
+  {at: 0.75, expect: 'rect(40px 15px 40px 15px)'},
+  {at: 1, expect: 'rect(20px 20px 20px 20px)'},
+  {at: 2, expect: 'rect(-60px 40px -60px 40px)'},
+]);
+
+test_no_interpolation({
+  property: 'clip',
+  from: 'unset',
+  to: 'rect(20px, 20px, 20px, 20px)',
+});
+
+test_interpolation({
+  property: 'clip',
+  from: 'rect(0px, 75px, 80px, 10px)',
+  to: 'rect(0px, 100px, 90px, 5px)'
+}, [
+  {at: -1, expect: 'rect(0px, 50px, 70px, 15px)'},
+  {at: 0, expect: 'rect(0px, 75px, 80px, 10px)'},
+  {at: 0.25, expect: 'rect(0px, 81.25px, 82.5px, 8.75px)'},
+  {at: 0.75, expect: 'rect(0px, 93.75px, 87.5px, 6.25px)'},
+  {at: 1, expect: 'rect(0px, 100px, 90px, 5px)'},
+  {at: 2, expect: 'rect(0px, 125px, 100px, 0px)'},
+]);
+
+test_no_interpolation({
+  property: 'clip',
+  from: 'rect(auto, auto, auto, 10px)',
+  to: 'rect(20px, 50px, 50px, auto)'
+});
+
+test_no_interpolation({
+  property: 'clip',
+  from: 'rect(auto, 0px, auto, 10px)',
+  to: 'rect(auto, 50px, 50px, auto)'
+});
+
+test_no_interpolation({
+  property: 'clip',
+  from: 'auto',
+  to: 'rect(0px, 50px, 50px, 0px)'
+});
+
+test_no_interpolation({
+  property: 'clip',
+  from: 'rect(0px, 50px, 50px, 0px)',
+  to: 'auto'
+});
+</script>