1 files changed, 22 insertions, 1 deletions
diff --git a/src/components/script/dom/domtokenlist.rs b/src/components/script/dom/domtokenlist.rs
index cf44d5f7abc..3d252d36731 100644
--- a/src/components/script/dom/domtokenlist.rs
+++ b/src/components/script/dom/domtokenlist.rs
@@ -5,14 +5,16 @@
 use dom::attr::{Attr, TokenListAttrValue};
 use dom::bindings::codegen::Bindings::DOMTokenListBinding;
 use dom::bindings::codegen::Bindings::DOMTokenListBinding::DOMTokenListMethods;
+use dom::bindings::error::{Fallible, InvalidCharacter, Syntax};
 use dom::bindings::global::Window;
 use dom::bindings::js::{JS, JSRef, Temporary, OptionalRootable};
 use dom::bindings::utils::{Reflector, Reflectable, reflect_dom_object};
 use dom::element::{Element, AttributeHandlers};
 use dom::node::window_from_node;
 
+use servo_util::atom::Atom;
 use servo_util::namespace::Null;
-use servo_util::str::DOMString;
+use servo_util::str::{DOMString, HTML_SPACE_CHARACTERS};
 
 #[deriving(Encodable)]
 pub struct DOMTokenList {
@@ -47,6 +49,7 @@ impl Reflectable for DOMTokenList {
 
 trait PrivateDOMTokenListHelpers {
     fn attribute(&self) -> Option<Temporary<Attr>>;
+    fn check_token_exceptions<'a>(&self, token: &'a str) -> Fallible<&'a str>;
 }
 
 impl<'a> PrivateDOMTokenListHelpers for JSRef<'a, DOMTokenList> {
@@ -54,6 +57,14 @@ impl<'a> PrivateDOMTokenListHelpers for JSRef<'a, DOMTokenList> {
         let element = self.element.root();
         element.deref().get_attribute(Null, self.local_name)
     }
+
+    fn check_token_exceptions<'a>(&self, token: &'a str) -> Fallible<&'a str> {
+        match token {
+            "" => Err(Syntax),
+            token if token.find(HTML_SPACE_CHARACTERS).is_some() => Err(InvalidCharacter),
+            token => Ok(token)
+        }
+    }
 }
 
 // http://dom.spec.whatwg.org/#domtokenlist
@@ -92,4 +103,14 @@ impl<'a> DOMTokenListMethods for JSRef<'a, DOMTokenList> {
         *found = item.is_some();
         item
     }
+
+    // http://dom.spec.whatwg.org/#dom-domtokenlist-contains
+    fn Contains(&self, token: DOMString) -> Fallible<bool> {
+        self.check_token_exceptions(token.as_slice()).map(|slice| {
+            self.attribute().root().and_then(|attr| attr.value().tokens().map(|mut tokens| {
+                let atom = Atom::from_slice(slice);
+                tokens.any(|token| *token == atom)
+            })).unwrap_or(false)
+        })
+    }
 }