Commit b31a2c49 authored by Emilio Cobos Álvarez's avatar Emilio Cobos Álvarez
Browse files

Bug 1730134 - Add some parsing and serialization tests for @layer. r=boris 

This uncovers some serialization bugs, and some missing null-checks
given the statement layer doesn't have a rule list.

Differential Revision: https://phabricator.services.mozilla.com/D125176
parent 694fef2d

layout/style/ServoCSSRuleList.cpp

+5 −3
Original line number Diff line number Diff line
@@ -33,8 +33,10 @@ ServoCSSRuleList::ServoCSSRuleList(already_AddRefed<ServoCssRules> aRawRules, 
                                   StyleSheet* aSheet,

                                   css::GroupRule* aParentRule)

    : mStyleSheet(aSheet), mParentRule(aParentRule), mRawRules(aRawRules) {

  if (mRawRules) {

    Servo_CssRules_ListTypes(mRawRules, &mRules);

  }

}



// QueryInterface implementation for ServoCSSRuleList

NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(ServoCSSRuleList)
@@ -166,7 +168,7 @@ nsresult ServoCSSRuleList::InsertRule(const nsACString& aRule, 
             "Caller must ensure that "

             "the list is not unlinked from stylesheet");



  if (IsReadOnly()) {

  if (!mRawRules || IsReadOnly()) {

    return NS_OK;

  }
@@ -198,7 +200,7 @@ nsresult ServoCSSRuleList::InsertRule(const nsACString& aRule, 
}



nsresult ServoCSSRuleList::DeleteRule(uint32_t aIndex) {

  if (IsReadOnly()) {

  if (!mRawRules || IsReadOnly()) {

    return NS_OK;

  }

servo/components/style/stylesheets/layer_rule.rs

+5 −3
Original line number Diff line number Diff line
@@ -242,8 +242,8 @@ impl ToCssWithGuard for LayerRule { 
                ref is_anonymous,

            } => {

                if !*is_anonymous {

                    name.to_css(&mut CssWriter::new(dest))?;

                    dest.write_char(' ')?;

                    name.to_css(&mut CssWriter::new(dest))?;

                }

                rules.read_with(guard).to_css_block(guard, dest)

            },
@@ -251,7 +251,9 @@ impl ToCssWithGuard for LayerRule { 
                let mut writer = CssWriter::new(dest);

                let mut first = true;

                for name in &**names {

                    if !first {

                    if first {

                        writer.write_char(' ')?;

                    } else {

                        writer.write_str(", ")?;

                    }

                    first = false;

testing/web-platform/tests/css/css-cascade/parsing/layer.html

0 → 100644
+25 −0
Original line number Diff line number Diff line 
<!doctype html>

<meta charset="utf-8">

<title>@layer rule parsing / serialization</title>

<link rel="author" title="Emilio Cobos Álvarez" href="mailto:emilio@crisal.io">

<link rel="author" title="Mozilla" href="https://mozilla.org">

<link rel="help" href="https://drafts.csswg.org/css-cascade-5/#layering">

<script src="/resources/testharness.js"></script>

<script src="/resources/testharnessreport.js"></script>

<script src="/css/support/parsing-testcommon.js"></script>

<script>

  test_valid_rule("@layer A;");

  test_valid_rule("@layer A, B, C;");

  test_valid_rule("@layer A.A;");

  test_valid_rule("@layer A, B.C.D, C;");



  test_invalid_rule("@layer;");

  test_invalid_rule("@layer A . A;");



  test_valid_rule("@layer {\n}");

  test_valid_rule("@layer A {\n}");

  test_valid_rule("@layer A.B {\n}");

  test_invalid_rule("@layer A . B {\n}");



  test_invalid_rule("@layer A, B, C {\n}");

</script>

testing/web-platform/tests/css/support/parsing-testcommon.js

+46 −0
Original line number Diff line number Diff line
@@ -95,3 +95,49 @@ function test_invalid_selector(selector) { 
          stringifiedSelector + " should throw in insertRule");

    }, stringifiedSelector + " should be an invalid selector");

}



// serialized can be the expected serialization of rule, or an array of

// permitted serializations, or omitted if value should serialize as rule.

function test_valid_rule(rule, serialized) {

    if (serialized === undefined)

        serialized = rule;



    test(function(){

        const style = document.createElement("style");

        document.head.append(style);

        const {sheet} = style;

        document.head.removeChild(style);

        const {cssRules} = sheet;



        assert_equals(cssRules.length, 0, "Sheet should have no rules");

        sheet.insertRule(rule);

        assert_equals(cssRules.length, 1, "Sheet should have 1 rule");



        const serialization = cssRules[0].cssText;

        if (Array.isArray(serialized))

            assert_in_array(serialization, serialized, "serialization should be sound");

        else

            assert_equals(serialization, serialized, "serialization should be canonical");



        sheet.deleteRule(0);

        assert_equals(cssRules.length, 0, "Sheet should have no rule");

        sheet.insertRule(serialization);

        assert_equals(cssRules.length, 1, "Sheet should have 1 rule");



        assert_equals(cssRules[0].cssText, serialization, "serialization should round-trip");

    }, rule + " should be a valid rule");

}



function test_invalid_rule(rule) {

    test(function(){

        const style = document.createElement("style");

        document.head.append(style);

        const {sheet} = style;

        document.head.removeChild(style);



        assert_throws_dom(

          DOMException.SYNTAX_ERR,

          () => sheet.insertRule(rule),

          rule + " should throw in insertRule");

    }, rule + " should be an invalid rule");

}