Improve coverage for callback this value
Includes CSSPaintCallback, MutationCallback, and IntersectionObserverCallback tests.
diff --git a/css/css-paint-api/paint-function-this-value.https.html b/css/css-paint-api/paint-function-this-value.https.html
new file mode 100644
index 0000000..2169138
--- /dev/null
+++ b/css/css-paint-api/paint-function-this-value.https.html
@@ -0,0 +1,43 @@
+<!DOCTYPE html>
+<html class="reftest-wait">
+<meta charset="utf-8">
+<title>Paint callback is invoked with `this` value of `paintInstance`</title>
+<link rel="help" href="https://drafts.css-houdini.org/css-paint-api-1/#invoke-a-paint-callback">
+<link rel="match" href="parse-input-arguments-ref.html">
+<style>
+.container {
+ width: 100px;
+ height: 100px;
+}
+
+#canvas-geometry {
+ background-image: paint(geometry);
+}
+</style>
+<script src="/common/reftest-wait.js"></script>
+<script src="/common/worklet-reftest.js"></script>
+<body>
+<div id="canvas-geometry" class="container"></div>
+
+<script id="code" type="text/worklet">
+let paintInstance;
+
+registerPaint('geometry', class {
+ constructor() {
+ paintInstance = this;
+ }
+ paint(ctx, geom) {
+ if (this === paintInstance)
+ ctx.fillStyle = 'green';
+ else
+ ctx.fillStyle = 'red';
+ ctx.fillRect(0, 0, geom.width, geom.height);
+ }
+});
+</script>
+
+<script>
+ importWorkletAndTerminateTestAfterAsyncPaint(CSS.paintWorklet, document.getElementById('code').textContent);
+</script>
+</body>
+</html>
diff --git a/dom/nodes/MutationObserver-callback-arguments.html b/dom/nodes/MutationObserver-callback-arguments.html
new file mode 100644
index 0000000..d64758c
--- /dev/null
+++ b/dom/nodes/MutationObserver-callback-arguments.html
@@ -0,0 +1,31 @@
+<!DOCTYPE HTML>
+<meta charset=utf-8>
+<title>MutationObserver: callback arguments</title>
+<link rel="help" href="https://dom.spec.whatwg.org/#notify-mutation-observers">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="mo-target"></div>
+<div id="log"></div>
+<script>
+"use strict";
+
+async_test(t => {
+ const moTarget = document.querySelector("#mo-target");
+ const mo = new MutationObserver(function(records, observer) {
+ t.step(() => {
+ assert_equals(this, mo);
+ assert_equals(arguments.length, 2);
+ assert_true(Array.isArray(records));
+ assert_equals(records.length, 1);
+ assert_true(records[0] instanceof MutationRecord);
+ assert_equals(observer, mo);
+
+ mo.disconnect();
+ t.done();
+ });
+ });
+
+ mo.observe(moTarget, {attributes: true});
+ moTarget.className = "trigger-mutation";
+}, "Callback is invoked with |this| value of MutationObserver and two arguments");
+</script>
diff --git a/intersection-observer/observer-callback-arguments.html b/intersection-observer/observer-callback-arguments.html
new file mode 100644
index 0000000..6e81696
--- /dev/null
+++ b/intersection-observer/observer-callback-arguments.html
@@ -0,0 +1,28 @@
+<!DOCTYPE HTML>
+<meta charset=utf-8>
+<title>IntersectionObserver: callback arguments</title>
+<link rel="help" href="https://w3c.github.io/IntersectionObserver/#notify-intersection-observers-algo">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="log"></div>
+<script>
+"use strict";
+
+async_test(t => {
+ const io = new IntersectionObserver(function(entries, observer) {
+ t.step(() => {
+ assert_equals(this, io);
+ assert_equals(arguments.length, 2);
+ assert_true(Array.isArray(entries));
+ assert_equals(entries.length, 1);
+ assert_true(entries[0] instanceof IntersectionObserverEntry);
+ assert_equals(observer, io);
+
+ io.disconnect();
+ t.done();
+ });
+ });
+
+ io.observe(document.body);
+}, "Callback is invoked with |this| value of IntersectionObserver and two arguments");
+</script>
