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use super::ETag;
use util::EntityTagRange;
use HeaderValue;
/// `If-Match` header, defined in
///
/// The `If-Match` header field makes the request method conditional on
/// the recipient origin server either having at least one current
/// representation of the target resource, when the field-value is "*",
/// or having a current representation of the target resource that has an
/// entity-tag matching a member of the list of entity-tags provided in
/// the field-value.
///
/// An origin server MUST use the strong comparison function when
/// comparing entity-tags for `If-Match`, since the client
/// intends this precondition to prevent the method from being applied if
/// there have been any changes to the representation data.
///
/// # ABNF
///
/// ```text
/// If-Match = "*" / 1#entity-tag
/// ```
///
/// # Example values
///
/// * `"xyzzy"`
/// * "xyzzy", "r2d2xxxx", "c3piozzzz"
///
/// # Examples
///
/// ```
/// # extern crate headers;
/// use headers::IfMatch;
///
/// let if_match = IfMatch::any();
/// ```
#[derive(Clone, Debug, PartialEq)]
pub struct IfMatch(EntityTagRange);
derive_header! {
IfMatch(_),
name: IF_MATCH
}
impl IfMatch {
/// Create a new `If-Match: *` header.
pub fn any() -> IfMatch {
IfMatch(EntityTagRange::Any)
}
/// Returns whether this is `If-Match: *`, matching any entity tag.
pub fn is_any(&self) -> bool {
match self.0 {
EntityTagRange::Any => true,
EntityTagRange::Tags(..) => false,
}
}
/// Checks whether the `ETag` strongly matches.
pub fn precondition_passes(&self, etag: &ETag) -> bool {
self.0.matches_strong(&etag.0)
}
}
impl From<ETag> for IfMatch {
fn from(etag: ETag) -> IfMatch {
IfMatch(EntityTagRange::Tags(HeaderValue::from(etag.0).into()))
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn is_any() {
assert!(IfMatch::any().is_any());
assert!(!IfMatch::from(ETag::from_static("\"yolo\"")).is_any());
}
#[test]
fn precondition_fails() {
let if_match = IfMatch::from(ETag::from_static("\"foo\""));
let bar = ETag::from_static("\"bar\"");
let weak_foo = ETag::from_static("W/\"foo\"");
assert!(!if_match.precondition_passes(&bar));
assert!(!if_match.precondition_passes(&weak_foo));
}
#[test]
fn precondition_passes() {
let foo = ETag::from_static("\"foo\"");
let if_match = IfMatch::from(foo.clone());
assert!(if_match.precondition_passes(&foo));
}
#[test]
fn precondition_any() {
let foo = ETag::from_static("\"foo\"");
let if_match = IfMatch::any();
assert!(if_match.precondition_passes(&foo));
}
}