style: Smoke-test the dependency tracking logic.

MozReview-Commit-ID: J5HWdS1H49s
Signed-off-by: Emilio Cobos Álvarez <emilio@crisal.io>

.travis.yml

@@ -22,6 +22,7 @@ matrix:
          - bash etc/ci/lockfile_changed.sh
          - bash etc/ci/manifest_changed.sh
          - ./mach cargo test -p selectors
+         - ./mach cargo test -p style
       cache:
         directories:
           - .cargo

components/selectors/parser.rs

@@ -1164,7 +1164,7 @@ pub mod tests {
     impl SelectorMethods for PseudoClass {
         type Impl = DummySelectorImpl;
 
-        fn visit<V>(&self, visitor: &mut V) -> bool
+        fn visit<V>(&self, _visitor: &mut V) -> bool
             where V: SelectorVisitor<Impl = Self::Impl> { true }
     }
 
@@ -1501,4 +1501,26 @@ pub mod tests {
             specificity: specificity(1, 1, 0),
         }))));
     }
+
+    struct TestVisitor {
+        seen: Vec<String>,
+    }
+
+    impl SelectorVisitor for TestVisitor {
+        type Impl = DummySelectorImpl;
+
+        fn visit_simple_selector(&mut self, s: &SimpleSelector<DummySelectorImpl>) -> bool {
+            let mut dest = String::new();
+            s.to_css(&mut dest).unwrap();
+            self.seen.push(dest);
+            true
+        }
+    }
+
+    #[test]
+    fn visitor() {
+        let mut test_visitor = TestVisitor { seen: vec![], };
+        parse(":not(:hover) ~ label").unwrap().0[0].visit(&mut test_visitor);
+        assert!(test_visitor.seen.contains(&":hover".into()));
+    }
 }

components/selectors/visitor.rs

@@ -7,7 +7,6 @@
 #![deny(missing_docs)]
 
 use parser::{AttrSelector, Combinator, ComplexSelector, SelectorImpl, SimpleSelector};
-use std::sync::Arc;
 
 /// A trait to visit selector properties.
 ///

components/style/restyle_hints.rs

@@ -279,7 +279,7 @@ impl<'a, E> Element for ElementWrapper<'a, E>
     fn match_non_ts_pseudo_class<F>(&self,
                                     pseudo_class: &NonTSPseudoClass,
                                     relations: &mut StyleRelations,
-                                    _: &mut F)
+                                    _setter: &mut F)
                                     -> bool
         where F: FnMut(&Self, ElementSelectorFlags),
     {
@@ -293,12 +293,12 @@ impl<'a, E> Element for ElementWrapper<'a, E>
                                              self,
                                              None,
                                              relations,
-                                             setter)
+                                             _setter)
                 })
             }
         }
 
-        let flag = SelectorImpl::pseudo_class_state_flag(pseudo_class);
+        let flag = pseudo_class.state_flag();
         if flag.is_empty() {
             return self.element.match_non_ts_pseudo_class(pseudo_class,
                                                           relations,
@@ -382,7 +382,7 @@ impl<'a, E> Element for ElementWrapper<'a, E>
 
 fn selector_to_state(sel: &SimpleSelector<SelectorImpl>) -> ElementState {
     match *sel {
-        SimpleSelector::NonTSPseudoClass(ref pc) => SelectorImpl::pseudo_class_state_flag(pc),
+        SimpleSelector::NonTSPseudoClass(ref pc) => pc.state_flag(),
         _ => ElementState::empty(),
     }
 }
@@ -505,6 +505,7 @@ impl SelectorVisitor for SensitivitiesVisitor {
                               combinator: Option<Combinator>) -> bool {
         self.hint |= combinator_to_restyle_hint(combinator);
         self.needs_revalidation |= self.hint.contains(RESTYLE_LATER_SIBLINGS);
+
         true
     }
 
@@ -577,21 +578,28 @@ impl DependencySet {
                 ss.visit(&mut sensitivities_visitor);
             }
 
-            sensitivities_visitor.hint |= combinator_to_restyle_hint(combinator);
             needs_revalidation |= sensitivities_visitor.needs_revalidation;
 
-            if !sensitivities_visitor.sensitivities.is_empty() {
+            let SensitivitiesVisitor {
+                sensitivities,
+                mut hint,
+                ..
+            } = sensitivities_visitor;
+
+            hint |= combinator_to_restyle_hint(combinator);
+
+            if !sensitivities.is_empty() {
                 self.add_dependency(Dependency {
-                    sensitivities: sensitivities_visitor.sensitivities,
+                    sensitivities: sensitivities,
-                    hint: sensitivities_visitor.hint,
+                    hint: hint,
                     selector: current.clone(),
                 })
             }
 
             match current.next {
                 Some((ref next, next_combinator)) => {
-                    combinator = Some(next_combinator);
                     current = next;
+                    combinator = Some(next_combinator);
                 }
                 None => break,
             }
@@ -697,3 +705,26 @@ impl DependencySet {
         }
     }
 }
+
+#[test]
+#[cfg(all(test, feature = "servo"))]
+fn smoke_restyle_hints() {
+    use cssparser::Parser;
+    use selector_parser::SelectorParser;
+    use stylesheets::{Origin, Namespaces};
+    let namespaces = Namespaces::default();
+    let parser = SelectorParser {
+        stylesheet_origin: Origin::Author,
+        namespaces: &namespaces,
+    };
+
+    let mut dependencies = DependencySet::new();
+
+    let mut p = Parser::new(":not(:active) ~ label");
+    let selector = Arc::new(ComplexSelector::parse(&parser, &mut p).unwrap());
+    dependencies.note_selector(&selector);
+    assert_eq!(dependencies.len(), 1);
+    assert_eq!(dependencies.state_deps.len(), 1);
+    assert!(!dependencies.state_deps[0].sensitivities.states.is_empty());
+    assert!(dependencies.state_deps[0].hint.contains(RESTYLE_LATER_SIBLINGS));
+}