Auto merge of #321 - cGuille:impl-hash-trait-for-origin, r=brson

Implement `Hash` for `Origin` (fix #302)

Hello,

I'm a Rust / Open Source beginner, so just explain if anything is wrong. :-)

I am giving a try at issue #302. I just derived the `Hash` for the `Origin` type.

I have zero experience with testing in Rust so I just tried to demonstrate that it works, but I do not know how to write a good test for this.

What should I do now?

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Author: bors-servo

src/origin.rs

@@ -50,7 +50,7 @@ pub fn url_origin(url: &Url) -> Origin {
 ///   the URL does not have the same origin as any other URL.
 ///
 /// For more information see https://url.spec.whatwg.org/#origin
-#[derive(PartialEq, Eq, Clone, Debug)]
+#[derive(PartialEq, Eq, Hash, Clone, Debug)]
 pub enum Origin {
     /// A globally unique identifier
     Opaque(OpaqueOrigin),
@@ -123,7 +123,7 @@ impl Origin {
 }
 
 /// Opaque identifier for URLs that have file or other schemes
-#[derive(Eq, PartialEq, Clone, Debug)]
+#[derive(Eq, PartialEq, Hash, Clone, Debug)]
 pub struct OpaqueOrigin(usize);
 
 #[cfg(feature = "heapsize")]

tests/unit.rs

@@ -372,3 +372,45 @@ fn define_encode_set_scopes() {
 
     m::test();
 }
+
+#[test]
+/// https://github.com/servo/rust-url/issues/302
+fn test_origin_hash() {
+    use std::hash::{Hash,Hasher};
+    use std::collections::hash_map::DefaultHasher;
+
+    fn hash<T: Hash>(value: &T) -> u64 {
+        let mut hasher = DefaultHasher::new();
+        value.hash(&mut hasher);
+        hasher.finish()
+    }
+
+    let origin = &Url::parse("http://example.net/").unwrap().origin();
+
+    let origins_to_compare = [
+        Url::parse("http://example.net:80/").unwrap().origin(),
+        Url::parse("http://example.net:81/").unwrap().origin(),
+        Url::parse("http://example.net").unwrap().origin(),
+        Url::parse("http://example.net/hello").unwrap().origin(),
+        Url::parse("https://example.net").unwrap().origin(),
+        Url::parse("ftp://example.net").unwrap().origin(),
+        Url::parse("file://example.net").unwrap().origin(),
+        Url::parse("http://[email protected]/").unwrap().origin(),
+        Url::parse("http://user:[email protected]/").unwrap().origin(),
+    ];
+
+    for origin_to_compare in &origins_to_compare {
+        if origin == origin_to_compare {
+            assert_eq!(hash(origin), hash(origin_to_compare));
+        } else {
+            assert_ne!(hash(origin), hash(origin_to_compare));
+        }
+    }
+
+    let opaque_origin = Url::parse("file://example.net").unwrap().origin();
+    let same_opaque_origin = Url::parse("file://example.net").unwrap().origin();
+    let other_opaque_origin = Url::parse("file://other").unwrap().origin();
+
+    assert_ne!(hash(&opaque_origin), hash(&same_opaque_origin));
+    assert_ne!(hash(&opaque_origin), hash(&other_opaque_origin));
+}