chromium/third_party/blink/web_tests/fast/css/nested-at-rules.html

<html>
<head>
<script src="../../resources/js-test.js"></script>
<style>
.test {
    content: "UNTOUCHED";
}

@media all {
    @media all {
        @font-face {
            src: local('Courier');
            font-family: Courier;
        }

        @page :left { top: 0 }

        #t0 { content: "APPLIED" }

        @import url("../../cssom/resources/import.css");
        @charset "UTF-8";
        @namespace "";
    }
    @media all {
        @media none {
            #t1 { content: "APPLIED" }
        }
    }
}
</style>
<body>
<span id=t0 class=test></span>
<span id=t1 class=test></span>
<script>
description("Test nested at-rules.");

evalAndLog("rules = document.styleSheets[1].cssRules");
shouldEvaluateTo("rules.length", 2);

shouldBe("rules[0].type", "CSSRule.STYLE_RULE");
shouldBe("rules[1].type", "CSSRule.MEDIA_RULE");
shouldEvaluateTo("rules[1].cssRules.length", 2);
shouldBe("rules[1].cssRules[0].type", "CSSRule.MEDIA_RULE");
shouldEvaluateTo("rules[1].cssRules[0].cssRules.length", 3);
shouldBe("rules[1].cssRules[0].cssRules[0].type", "CSSRule.FONT_FACE_RULE");
shouldBe("rules[1].cssRules[0].cssRules[1].type", "CSSRule.PAGE_RULE");
shouldBe("rules[1].cssRules[0].cssRules[2].type", "CSSRule.STYLE_RULE");
shouldBe("rules[1].cssRules[0].cssRules[0].parentStyleSheet", "document.styleSheets[1]");
shouldBe("rules[1].cssRules[0].cssRules[1].parentStyleSheet", "document.styleSheets[1]");
shouldBe("rules[1].cssRules[0].cssRules[2].parentStyleSheet", "document.styleSheets[1]");

shouldBe("rules[1].cssRules[1].type", "CSSRule.MEDIA_RULE");
shouldEvaluateTo("rules[1].cssRules[1].cssRules.length", 1);
shouldBe("rules[1].cssRules[1].cssRules[0].type", "CSSRule.MEDIA_RULE");
evalAndLog("rules[1].cssRules[1].insertRule('@media all { @page :left { top: 0; } }', 1)");
shouldEvaluateTo("rules[1].cssRules[1].cssRules.length", 2);
shouldBe("rules[1].cssRules[1].cssRules[1].type", "CSSRule.MEDIA_RULE");
shouldBe("rules[1].cssRules[1].cssRules[1].cssRules[0].type", "CSSRule.PAGE_RULE");

shouldBeEqualToString("getComputedStyle(document.getElementById('t0')).content", '"APPLIED"');
shouldBeEqualToString("getComputedStyle(document.getElementById('t1')).content", '"UNTOUCHED"');
</script>