fix(headers): Fix formatting of 0 qualites and formatting of empty list header fields.

src/header/common/accept_encoding.rs

@@ -24,24 +24,7 @@ header! {
         test_header!(test3, vec![b"*"]);
         // Note: Removed quality 1 from gzip
         test_header!(test4, vec![b"compress;q=0.5, gzip"]);
-        // FIXME: Formatting of 0 as quality value
-        // test_header!(test5, vec![b"gzip;q=1.0, identity; q=0.5, *;q=0"]);
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use header::{Encoding, Header, qitem, Quality, QualityItem};
-
-    use super::*;
-
-    #[test]
-    fn test_parse_header() {
-        let a: AcceptEncoding = Header::parse_header([b"gzip;q=1.0, identity; q=0.5".to_vec()].as_ref()).unwrap();
-        let b = AcceptEncoding(vec![
-            qitem(Encoding::Gzip),
-            QualityItem::new(Encoding::Identity, Quality(500)),
-        ]);
-        assert_eq!(a, b);
+        // Note: Removed quality 1 from gzip
+        test_header!(test5, vec![b"gzip, identity; q=0.5, *;q=0"]);
     }
 }

src/header/common/allow.rs

@@ -35,11 +35,10 @@ header! {
                 Method::Connect,
                 Method::Patch,
                 Method::Extension("fOObAr".to_string())])));
-        // FIXME: Formatting fails
-        // test_header!(
-        //    test3,
-        //    vec![b""],
-        //    Some(HeaderField(Vec::<Method>::new())));
+        test_header!(
+            test3,
+            vec![b""],
+            Some(HeaderField(Vec::<Method>::new())));
     }
 }
 

src/header/parsing.rs

@@ -40,13 +40,12 @@ pub fn from_one_comma_delimited<T: str::FromStr>(raw: &[u8]) -> Option<Vec<T>> {
 }
 
 /// Format an array into a comma-delimited string.
-pub fn fmt_comma_delimited<T: fmt::Display>(fmt: &mut fmt::Formatter, parts: &[T]) -> fmt::Result {
-    let last = parts.len() - 1;
+pub fn fmt_comma_delimited<T: fmt::Display>(f: &mut fmt::Formatter, parts: &[T]) -> fmt::Result {
     for (i, part) in parts.iter().enumerate() {
-        try!(write!(fmt, "{}", part));
-        if i < last {
-            try!(write!(fmt, ", "));
+        if i > 0 {
+            try!(write!(f, ", "));
         }
+        try!(write!(f, "{}", part));
     }
     Ok(())
 }

src/header/shared/quality_item.rs

@@ -24,10 +24,10 @@ pub struct Quality(pub u16);
 
 impl fmt::Display for Quality {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        if self.0 == 1000 {
-            write!(f, "")
-        } else {
-            write!(f, "; q=0.{}", format!("{:03}", self.0).trim_right_matches('0'))
+        match self.0 {
+            1000 => Ok(()),
+            0 => f.write_str("; q=0"),
+            x => write!(f, "; q=0.{}", format!("{:03}", x).trim_right_matches('0'))
         }
     }
 }
@@ -196,6 +196,11 @@ mod tests {
         assert_eq!(q(0.5), Quality(500));
     }
 
+    #[test]
+    fn test_quality2() {
+        assert_eq!(format!("{}", q(0.0)), "; q=0");
+    }
+
     #[test]
     #[should_panic]
     fn test_quality_invalid() {