LayoutTests/inspector/css/add-css-property-without-source-range.html

<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<script src="../../http/tests/inspector/resources/inspector-test.js"></script>
<script>
function test() {
    let suite = InspectorTest.createAsyncSuite("AddCSSPropertyWithoutSourceRange");

    suite.addTestCase({
        name: "AddCSSPropertyWithoutSourceRange",
        description: "newBlankProperty should not throw for a style that has no source range, such as a user agent rule.",
        async test() {
            let documentNode = await WI.domManager.requestDocument();
            let nodeId = await documentNode.querySelector("#target");
            let domNode = WI.domManager.nodeForId(nodeId);
            let nodeStyles = WI.cssManager.stylesForNode(domNode);
            await nodeStyles.refreshIfNeeded();

            let style = nodeStyles.matchedRules.map((rule) => rule.style).find((rule) => !rule.styleSheetTextRange);
            InspectorTest.expectThat(style, "Should have a matched style with no source range.");
            if (!style)
                return;

            for (let index of [0, 1, 2]) {
                let threw = false;
                let property = null;
                try {
                    property = style.newBlankProperty(index);
                } catch (exception) {
                    threw = true;
                    InspectorTest.log(`newBlankProperty(${index}) threw: ${exception}`);
                }
                InspectorTest.expectThat(!threw, `newBlankProperty(${index}) should not throw for a style with no source range.`);
                InspectorTest.expectThat(property, `newBlankProperty(${index}) should return a property.`);
            }
        }
    });

    suite.runTestCasesAndFinish();
}
</script>
</head>
<body onload="runTest()">
<p>Testing that adding a CSS property to a style with no source range does not throw.</p>
<div id="target"></div>
</body>
</html>