use crate::ensure_eq_status;
use crate::headers::{HeaderName, HeaderValue, Headers, ToHeaderValues, EXPECT};
use std::fmt::Debug;
use std::option;
#[derive(Debug, Ord, PartialOrd, Eq, PartialEq)]
pub struct Expect {
_priv: (),
}
impl Expect {
pub fn new() -> Self {
Self { _priv: () }
}
pub fn from_headers(headers: impl AsRef<Headers>) -> crate::Result<Option<Self>> {
let headers = match headers.as_ref().get(EXPECT) {
Some(headers) => headers,
None => return Ok(None),
};
let header = headers.iter().last().unwrap();
ensure_eq_status!(header, "100-continue", 400, "malformed `Expect` header");
Ok(Some(Self { _priv: () }))
}
pub fn apply(&self, mut headers: impl AsMut<Headers>) {
headers.as_mut().insert(EXPECT, self.value());
}
pub fn name(&self) -> HeaderName {
EXPECT
}
pub fn value(&self) -> HeaderValue {
let value = "100-continue";
unsafe { HeaderValue::from_bytes_unchecked(value.into()) }
}
}
impl ToHeaderValues for Expect {
type Iter = option::IntoIter<HeaderValue>;
fn to_header_values(&self) -> crate::Result<Self::Iter> {
Ok(self.value().to_header_values().unwrap())
}
}
#[cfg(test)]
mod test {
use super::*;
use crate::headers::Headers;
#[test]
fn smoke() -> crate::Result<()> {
let expect = Expect::new();
let mut headers = Headers::new();
expect.apply(&mut headers);
let expect = Expect::from_headers(headers)?.unwrap();
assert_eq!(expect, Expect::new());
Ok(())
}
#[test]
fn bad_request_on_parse_error() {
let mut headers = Headers::new();
headers.insert(EXPECT, "<nori ate the tag. yum.>");
let err = Expect::from_headers(headers).unwrap_err();
assert_eq!(err.status(), 400);
}
}