1 files changed, 86 insertions, 0 deletions
diff --git a/third_party/rust/headers/src/common/expect.rs b/third_party/rust/headers/src/common/expect.rs
new file mode 100644
index 0000000000..a1caf2530d
--- /dev/null
+++ b/third_party/rust/headers/src/common/expect.rs
@@ -0,0 +1,86 @@
+use std::fmt;
+
+use util::IterExt;
+
+/// The `Expect` header.
+///
+/// > The "Expect" header field in a request indicates a certain set of
+/// > behaviors (expectations) that need to be supported by the server in
+/// > order to properly handle this request.  The only such expectation
+/// > defined by this specification is 100-continue.
+/// >
+/// >    Expect  = "100-continue"
+///
+/// # Example
+///
+/// ```
+/// # extern crate headers;
+/// use headers::Expect;
+///
+/// let expect = Expect::CONTINUE;
+/// ```
+#[derive(Clone, PartialEq)]
+pub struct Expect(());
+
+impl Expect {
+    /// "100-continue"
+    pub const CONTINUE: Expect = Expect(());
+}
+
+impl ::Header for Expect {
+    fn name() -> &'static ::HeaderName {
+        &::http::header::EXPECT
+    }
+
+    fn decode<'i, I: Iterator<Item = &'i ::HeaderValue>>(values: &mut I) -> Result<Self, ::Error> {
+        values
+            .just_one()
+            .and_then(|value| {
+                if value == "100-continue" {
+                    Some(Expect::CONTINUE)
+                } else {
+                    None
+                }
+            })
+            .ok_or_else(::Error::invalid)
+    }
+
+    fn encode<E: Extend<::HeaderValue>>(&self, values: &mut E) {
+        values.extend(::std::iter::once(::HeaderValue::from_static(
+            "100-continue",
+        )));
+    }
+}
+
+impl fmt::Debug for Expect {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        f.debug_tuple("Expect").field(&"100-continue").finish()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::super::test_decode;
+    use super::Expect;
+
+    #[test]
+    fn expect_continue() {
+        assert_eq!(
+            test_decode::<Expect>(&["100-continue"]),
+            Some(Expect::CONTINUE),
+        );
+    }
+
+    #[test]
+    fn expectation_failed() {
+        assert_eq!(test_decode::<Expect>(&["sandwich"]), None,);
+    }
+
+    #[test]
+    fn too_many_values() {
+        assert_eq!(
+            test_decode::<Expect>(&["100-continue", "100-continue"]),
+            None,
+        );
+    }
+}