Implement CSSStyleRule.selectorText.

We parse when assigning using the namespaces of the stylesheet. It isn't
clear if the spec says to do that (Firefox doesn't support the setter at
all, Chrome does, Safari doesn't); the spec issue is here:
https://github.com/w3c/csswg-drafts/issues/1511

Also fix ToCss implementation of AttrSelectorOperator to not pad with
spaces, to conform with CSSOM. This means we have to update some unit
tests that expect operators with spaces around them in attribute
selectors to roundtrip.

See the "attribute selector" section of "Serializing Selectors" here:
https://drafts.csswg.org/cssom/#serializing-selectors

CSSStyleRule.selectorText is specified here:
https://drafts.csswg.org/cssom/#dom-cssstylerule-selectortext

14 files changed, 109 insertions, 100 deletions

diff --git a/components/script/dom/cssstyledeclaration.rs b/components/script/dom/cssstyledeclaration.rs
index 8e17e50a8fa..572550b2bc9 100644
--- a/components/script/dom/cssstyledeclaration.rs
+++ b/components/script/dom/cssstyledeclaration.rs
@@ -104,6 +104,8 @@ impl CSSStyleOwner {
                     f(&mut *pdb.write_with(&mut guard), &mut changed)
                 };
                 if changed {
+                    // If this is changed, see also
+                    // CSSStyleRule::SetSelectorText, which does the same thing.
                     rule.global().as_window().Document().invalidate_stylesheets();
                 }
                 result
diff --git a/components/script/dom/cssstylerule.rs b/components/script/dom/cssstylerule.rs
index 607f2cfb816..f9df3afc2ad 100644
--- a/components/script/dom/cssstylerule.rs
+++ b/components/script/dom/cssstylerule.rs
@@ -2,7 +2,10 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
+use cssparser::{Parser as CssParser, ParserInput as CssParserInput};
+use cssparser::ToCss;
 use dom::bindings::codegen::Bindings::CSSStyleRuleBinding::{self, CSSStyleRuleMethods};
+use dom::bindings::codegen::Bindings::WindowBinding::WindowBinding::WindowMethods;
 use dom::bindings::inheritance::Castable;
 use dom::bindings::js::{JS, MutNullableJS, Root};
 use dom::bindings::reflector::{DomObject, reflect_dom_object};
@@ -12,9 +15,12 @@ use dom::cssstyledeclaration::{CSSModificationAccess, CSSStyleDeclaration, CSSSt
 use dom::cssstylesheet::CSSStyleSheet;
 use dom::window::Window;
 use dom_struct::dom_struct;
+use selectors::parser::SelectorList;
+use std::mem;
+use style::selector_parser::SelectorParser;
 use style::shared_lock::{Locked, ToCssWithGuard};
 use style::stylearc::Arc;
-use style::stylesheets::StyleRule;
+use style::stylesheets::{StyleRule, Origin};
 
 #[dom_struct]
 pub struct CSSStyleRule {
@@ -71,4 +77,33 @@ impl CSSStyleRuleMethods for CSSStyleRule {
             )
         })
     }
+
+    // https://drafts.csswg.org/cssom/#dom-cssstylerule-selectortext
+    fn SelectorText(&self) -> DOMString {
+        let guard = self.cssrule.shared_lock().read();
+        let stylerule = self.stylerule.read_with(&guard);
+        return DOMString::from_string(stylerule.selectors.to_css_string());
+    }
+
+    // https://drafts.csswg.org/cssom/#dom-cssstylerule-selectortext
+    fn SetSelectorText(&self, value: DOMString) {
+        // It's not clear from the spec if we should use the stylesheet's namespaces.
+        // https://github.com/w3c/csswg-drafts/issues/1511
+        let namespaces = self.cssrule.parent_stylesheet().style_stylesheet().contents.namespaces.read();
+        let parser = SelectorParser {
+            stylesheet_origin: Origin::Author,
+            namespaces: &namespaces,
+        };
+        let mut css_parser = CssParserInput::new(&*value);
+        let mut css_parser = CssParser::new(&mut css_parser);
+        if let Ok(mut s) = SelectorList::parse(&parser, &mut css_parser) {
+            // This mirrors what we do in CSSStyleOwner::mutate_associated_block.
+            let mut guard = self.cssrule.shared_lock().write();
+            let mut stylerule = self.stylerule.write_with(&mut guard);
+            mem::swap(&mut stylerule.selectors, &mut s);
+            // It seems like we will want to avoid having to invalidate all
+            // stylesheets eventually!
+            self.global().as_window().Document().invalidate_stylesheets();
+        }
+    }
 }
diff --git a/components/script/dom/webidls/CSSStyleRule.webidl b/components/script/dom/webidls/CSSStyleRule.webidl
index 145650a916c..8b85b863bb2 100644
--- a/components/script/dom/webidls/CSSStyleRule.webidl
+++ b/components/script/dom/webidls/CSSStyleRule.webidl
@@ -5,6 +5,6 @@
 // https://drafts.csswg.org/cssom/#the-cssstylerule-interface
 [Exposed=Window]
 interface CSSStyleRule : CSSRule {
-  // attribute DOMString selectorText;
+  attribute DOMString selectorText;
   [SameObject, PutForwards=cssText] readonly attribute CSSStyleDeclaration style;
 };
diff --git a/components/selectors/attr.rs b/components/selectors/attr.rs
index da208c94b1f..b71be2cca73 100644
--- a/components/selectors/attr.rs
+++ b/components/selectors/attr.rs
@@ -78,13 +78,15 @@ pub enum AttrSelectorOperator {
 
 impl ToCss for AttrSelectorOperator {
     fn to_css<W>(&self, dest: &mut W) -> fmt::Result where W: fmt::Write {
+        // https://drafts.csswg.org/cssom/#serializing-selectors
+        // See "attribute selector".
         dest.write_str(match *self {
-            AttrSelectorOperator::Equal => " = ",
-            AttrSelectorOperator::Includes => " ~= ",
-            AttrSelectorOperator::DashMatch => " |= ",
-            AttrSelectorOperator::Prefix => " ^= ",
-            AttrSelectorOperator::Substring => " *= ",
-            AttrSelectorOperator::Suffix => " $= ",
+            AttrSelectorOperator::Equal => "=",
+            AttrSelectorOperator::Includes => "~=",
+            AttrSelectorOperator::DashMatch => "|=",
+            AttrSelectorOperator::Prefix => "^=",
+            AttrSelectorOperator::Substring => "*=",
+            AttrSelectorOperator::Suffix => "$=",
         })
     }
 }
diff --git a/components/selectors/parser.rs b/components/selectors/parser.rs
index 676c1946822..022e3a06647 100644
--- a/components/selectors/parser.rs
+++ b/components/selectors/parser.rs
@@ -1934,7 +1934,7 @@ pub mod tests {
                 ].into_boxed_slice())
             ), specificity(0, 0, 1))
         ))));
-        assert_eq!(parse("[attr |= \"foo\"]"), Ok(SelectorList::from_vec(vec!(
+        assert_eq!(parse("[attr|=\"foo\"]"), Ok(SelectorList::from_vec(vec!(
             Selector::from_vec(vec!(
                 Component::AttributeInNoNamespace {
                     local_name: DummyAtom::from("attr"),
@@ -1993,7 +1993,7 @@ pub mod tests {
         parser.default_ns = None;
         assert!(parse(":not(#provel.old)").is_err());
         assert!(parse(":not(#provel > old)").is_err());
-        assert!(parse("table[rules]:not([rules = \"none\"]):not([rules = \"\"])").is_ok());
+        assert!(parse("table[rules]:not([rules=\"none\"]):not([rules=\"\"])").is_ok());
         assert_eq!(parse(":not(#provel)"), Ok(SelectorList::from_vec(vec!(
             Selector::from_vec(vec!(Component::Negation(vec!(
                     Component::ID(DummyAtom::from("provel")),
diff --git a/tests/unit/style/parsing/selectors.rs b/tests/unit/style/parsing/selectors.rs
index 4f9d931197b..15611dd093c 100644
--- a/tests/unit/style/parsing/selectors.rs
+++ b/tests/unit/style/parsing/selectors.rs
@@ -23,5 +23,5 @@ fn test_selectors() {
     assert_roundtrip!(parse_selector, "div");
     assert_roundtrip!(parse_selector, "svg|circle");
     assert_roundtrip!(parse_selector, "p:before", "p::before");
-    assert_roundtrip!(parse_selector, "[border = \"0\"]:-servo-nonzero-border ~ ::-servo-details-summary");
+    assert_roundtrip!(parse_selector, "[border=\"0\"]:-servo-nonzero-border ~ ::-servo-details-summary");
 }
diff --git a/tests/wpt/metadata-css/cssom-1_dev/html/cssstylerule.htm.ini b/tests/wpt/metadata-css/cssom-1_dev/html/cssstylerule.htm.ini
index 70d0be16aa7..8ce322a482b 100644
--- a/tests/wpt/metadata-css/cssom-1_dev/html/cssstylerule.htm.ini
+++ b/tests/wpt/metadata-css/cssom-1_dev/html/cssstylerule.htm.ini
@@ -15,6 +15,3 @@
   [StyleRule_properties]
     expected: FAIL
 
-  [StyleRule_properties_values]
-    expected: FAIL
-
diff --git a/tests/wpt/metadata-css/cssom-1_dev/html/interfaces.htm.ini b/tests/wpt/metadata-css/cssom-1_dev/html/interfaces.htm.ini
index 5b782cc150e..53dc0324df2 100644
--- a/tests/wpt/metadata-css/cssom-1_dev/html/interfaces.htm.ini
+++ b/tests/wpt/metadata-css/cssom-1_dev/html/interfaces.htm.ini
@@ -117,12 +117,6 @@
   [CSSRule interface: attribute parentRule]
     expected: FAIL
 
-  [CSSStyleRule interface: attribute selectorText]
-    expected: FAIL
-
-  [CSSStyleRule interface: style_element.sheet.cssRules[0\] must inherit property "selectorText" with the proper type (0)]
-    expected: FAIL
-
   [CSSRule interface: style_element.sheet.cssRules[0\] must inherit property "parentRule" with the proper type (10)]
     expected: FAIL
 
diff --git a/tests/wpt/metadata/MANIFEST.json b/tests/wpt/metadata/MANIFEST.json
index 58ee872a951..45a49991d1e 100644
--- a/tests/wpt/metadata/MANIFEST.json
+++ b/tests/wpt/metadata/MANIFEST.json
@@ -160103,6 +160103,18 @@
      {}
     ]
    ],
+   "cssom/selectorText-modification-restyle-001.html": [
+    [
+     "/cssom/selectorText-modification-restyle-001.html",
+     [
+      [
+       "/cssom/selectorText-modification-restyle-001-ref.html",
+       "=="
+      ]
+     ],
+     {}
+    ]
+   ],
    "html/dom/elements/global-attributes/dir_auto-EN-L.html": [
     [
      "/html/dom/elements/global-attributes/dir_auto-EN-L.html",
@@ -274610,6 +274622,11 @@
      {}
     ]
    ],
+   "cssom/selectorText-modification-restyle-001-ref.html": [
+    [
+     {}
+    ]
+   ],
    "cssom/stylesheet-same-origin.css": [
     [
      {}
@@ -553977,6 +553994,14 @@
    "002777c7c598eb1131ab625365ee3fe08650e830",
    "testharness"
   ],
+  "cssom/selectorText-modification-restyle-001-ref.html": [
+   "4fbe124f09131f30e5c68154774246e5cd15b14a",
+   "support"
+  ],
+  "cssom/selectorText-modification-restyle-001.html": [
+   "ac5a5414dd849151c3ca6348c90c0f4e80a09b75",
+   "reftest"
+  ],
   "cssom/serialization-CSSDeclaration-with-important.html": [
    "ecc8b95fb2d71cacee271f4fea2fc16f35cdba57",
    "testharness"
diff --git a/tests/wpt/metadata/cssom/CSSStyleRule.html.ini b/tests/wpt/metadata/cssom/CSSStyleRule.html.ini
index 4b0ba813427..5cdf89a296a 100644
--- a/tests/wpt/metadata/cssom/CSSStyleRule.html.ini
+++ b/tests/wpt/metadata/cssom/CSSStyleRule.html.ini
@@ -9,9 +9,3 @@
   [Values of CSSRule attributes]
     expected: FAIL
 
-  [Values of CSSStyleRule attributes]
-    expected: FAIL
-
-  [Existence and type of CSSStyleRule attributes]
-    expected: FAIL
-
diff --git a/tests/wpt/metadata/cssom/interfaces.html.ini b/tests/wpt/metadata/cssom/interfaces.html.ini
index 532de09173f..0b9d9c1b706 100644
--- a/tests/wpt/metadata/cssom/interfaces.html.ini
+++ b/tests/wpt/metadata/cssom/interfaces.html.ini
@@ -54,12 +54,6 @@
   [CSSRule interface: attribute parentRule]
     expected: FAIL
 
-  [CSSStyleRule interface: attribute selectorText]
-    expected: FAIL
-
-  [CSSStyleRule interface: style_element.sheet.cssRules[0\] must inherit property "selectorText" with the proper type (0)]
-    expected: FAIL
-
   [CSSRule interface: style_element.sheet.cssRules[0\] must inherit property "parentRule" with the proper type (10)]
     expected: FAIL
 
diff --git a/tests/wpt/metadata/selectors/attribute-selectors/attribute-case/cssom.html.ini b/tests/wpt/metadata/selectors/attribute-selectors/attribute-case/cssom.html.ini
deleted file mode 100644
index 4b2a69d99a6..00000000000
--- a/tests/wpt/metadata/selectors/attribute-selectors/attribute-case/cssom.html.ini
+++ /dev/null
@@ -1,68 +0,0 @@
-[cssom.html]
-  type: testharness
-  [[foo="bar"\] /* sanity check */ getting CSSRule#cssText]
-    expected: FAIL
-
-  [[foo="bar"\] /* sanity check */ getting CSSStyleRule#selectorText]
-    expected: FAIL
-
-  [[foo="bar"\] /* sanity check */ setting CSSStyleRule#selectorText]
-    expected: FAIL
-
-  [[foo="bar"\] /* sanity check */ getting CSSRule#cssText in @media]
-    expected: FAIL
-
-  [[foo="bar"\] /* sanity check */ getting CSSStyleRule#selectorText in @media]
-    expected: FAIL
-
-  [[foo="bar"\] /* sanity check */ setting CSSStyleRule#selectorText in @media]
-    expected: FAIL
-
-  [[foo="bar" i\] getting CSSRule#cssText]
-    expected: FAIL
-
-  [[foo="bar" i\] getting CSSStyleRule#selectorText]
-    expected: FAIL
-
-  [[foo="bar" i\] getting CSSRule#cssText in @media]
-    expected: FAIL
-
-  [[foo="bar" i\] getting CSSStyleRule#selectorText in @media]
-    expected: FAIL
-
-  [[foo="bar" /**/ i\] getting CSSRule#cssText]
-    expected: FAIL
-
-  [[foo="bar" /**/ i\] getting CSSStyleRule#selectorText]
-    expected: FAIL
-
-  [[foo="bar" /**/ i\] setting CSSStyleRule#selectorText]
-    expected: FAIL
-
-  [[foo="bar" /**/ i\] getting CSSRule#cssText in @media]
-    expected: FAIL
-
-  [[foo="bar" /**/ i\] getting CSSStyleRule#selectorText in @media]
-    expected: FAIL
-
-  [[foo="bar" /**/ i\] setting CSSStyleRule#selectorText in @media]
-    expected: FAIL
-
-  [[foo="bar"/**/i\] getting CSSRule#cssText]
-    expected: FAIL
-
-  [[foo="bar"/**/i\] getting CSSStyleRule#selectorText]
-    expected: FAIL
-
-  [[foo="bar"/**/i\] setting CSSStyleRule#selectorText]
-    expected: FAIL
-
-  [[foo="bar"/**/i\] getting CSSRule#cssText in @media]
-    expected: FAIL
-
-  [[foo="bar"/**/i\] getting CSSStyleRule#selectorText in @media]
-    expected: FAIL
-
-  [[foo="bar"/**/i\] setting CSSStyleRule#selectorText in @media]
-    expected: FAIL
-
diff --git a/tests/wpt/web-platform-tests/cssom/selectorText-modification-restyle-001-ref.html b/tests/wpt/web-platform-tests/cssom/selectorText-modification-restyle-001-ref.html
new file mode 100644
index 00000000000..74e58074708
--- /dev/null
+++ b/tests/wpt/web-platform-tests/cssom/selectorText-modification-restyle-001-ref.html
@@ -0,0 +1,13 @@
+<!doctype html>
+<meta charset="utf-8">
+<title>(Ref #1) CSSOM - CSSStyleRule.selectorText Modification Restyle - Reference #1</title>
+
+<style>
+div {
+  color: green;
+}
+</style>
+
+<body>
+<div>I should be green.</div>
+</body>
diff --git a/tests/wpt/web-platform-tests/cssom/selectorText-modification-restyle-001.html b/tests/wpt/web-platform-tests/cssom/selectorText-modification-restyle-001.html
new file mode 100644
index 00000000000..681d32f1865
--- /dev/null
+++ b/tests/wpt/web-platform-tests/cssom/selectorText-modification-restyle-001.html
@@ -0,0 +1,21 @@
+<!doctype html>
+<meta charset="utf-8">
+<title>(Test #1) CSSOM - CSSStyleRule.selectorText Modification Restyle - Test #1</title>
+<link rel="match" href="selectorText-modification-restyle-001-ref.html">
+
+<style>
+@namespace bogus url(http://example.com/bogus);
+
+bogus|div {
+  color: green;
+}
+</style>
+
+<body>
+<div>I should be green.</div>
+<script>
+// Remove the "bogus" namespace--now it should apply to the div above.
+// We also expect to see a restyle.
+document.querySelector("style").sheet.cssRules[1].selectorText = "div";
+</script>
+</body>