headers_ext/common/
expect.rs1use std::fmt;
2
3use util::IterExt;
4
5#[derive(Clone, PartialEq)]
23pub struct Expect(());
24
25impl Expect {
26 pub const CONTINUE: Expect = Expect(());
28}
29
30impl ::Header for Expect {
31 const NAME: &'static ::HeaderName = &::http::header::EXPECT;
32
33 fn decode<'i, I: Iterator<Item = &'i ::HeaderValue>>(values: &mut I) -> Result<Self, ::Error> {
34 values
35 .just_one()
36 .and_then(|value| {
37 if value == "100-continue" {
38 Some(Expect::CONTINUE)
39 } else {
40 None
41 }
42 })
43 .ok_or_else(::Error::invalid)
44 }
45
46 fn encode<E: Extend<::HeaderValue>>(&self, values: &mut E) {
47 values.extend(::std::iter::once(::HeaderValue::from_static("100-continue")));
48 }
49}
50
51impl fmt::Debug for Expect {
52 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
53 f.debug_tuple("Expect")
54 .field(&"100-continue")
55 .finish()
56 }
57}
58
59#[cfg(test)]
60mod tests {
61 use super::Expect;
62 use super::super::test_decode;
63
64 #[test]
65 fn expect_continue() {
66 assert_eq!(
67 test_decode::<Expect>(&["100-continue"]),
68 Some(Expect::CONTINUE),
69 );
70 }
71
72 #[test]
73 fn expectation_failed() {
74 assert_eq!(
75 test_decode::<Expect>(&["sandwich"]),
76 None,
77 );
78 }
79
80 #[test]
81 fn too_many_values() {
82 assert_eq!(
83 test_decode::<Expect>(&["100-continue", "100-continue"]),
84 None,
85 );
86 }
87}