test passes

src/cache/cache_control/cache_control.rs

@@ -29,7 +29,9 @@ impl CacheControl {
             for part in value.as_str().trim().split(',') {
                 // Try and parse a directive from a str. If the directive is
                 // unkown we skip it.
-                if let Some(entry) = CacheDirective::from_str(part.trim_start())? {
+                let s = part.trim_start();
+                s.to_lowercase();
+                if let Some(entry) = CacheDirective::from_str(s)? {
                     entries.push(entry);
                 }
             }

src/cache/cache_control/cache_directive.rs

@@ -4,7 +4,7 @@ use crate::Status;
 use std::time::Duration;
 
 /// An HTTP `Cache-Control` directive.
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, PartialEq, Eq)]
 pub enum CacheDirective {
     /// The response body will not change over time.
     Immutable,
@@ -87,6 +87,7 @@ impl CacheDirective {
 
         // This won't panic because each input string has at least one part.
         let res = match next {
+            "immutable" => Some(Immutable),
             "no-cache" => Some(NoCache),
             "no-store" => Some(NoStore),
             "no-transform" => Some(NoTransform),

src/cache/cache_control/mod.rs

@@ -11,3 +11,25 @@ mod cache_directive;
 
 pub use cache_control::CacheControl;
 pub use cache_directive::CacheDirective;
+
+#[cfg(test)]
+mod test {
+    use super::*;
+    use crate::headers::Headers;
+
+    #[test]
+    fn smoke() -> crate::Result<()> {
+        let mut entries = CacheControl::new();
+        entries.push(CacheDirective::Immutable);
+        entries.push(CacheDirective::NoStore);
+
+        let mut headers = Headers::new();
+        entries.apply(&mut headers);
+
+        let entries = CacheControl::from_headers(headers)?.unwrap();
+        let mut entries = entries.iter();
+        assert_eq!(entries.next().unwrap(), &CacheDirective::Immutable);
+        assert_eq!(entries.next().unwrap(), &CacheDirective::NoStore);
+        Ok(())
+    }
+}