From 075d871e6392d5970908d95e1e043cf16aac1e3b Mon Sep 17 00:00:00 2001
From: Rob Ede <robjtede@icloud.com>
Date: Thu, 2 Dec 2021 13:59:25 +0000
Subject: [PATCH 1/3] wrap `LanguageTags` type in new `AnyOrSome` type to
 support wildcards (#2480)

---
 CHANGES.md                                   |  11 +
 actix-http/src/header/mod.rs                 |   2 +-
 actix-http/src/header/shared/quality_item.rs |  15 +-
 actix-http/src/header/utils.rs               |  31 ++-
 src/http/header/accept.rs                    |  51 +++--
 src/http/header/accept_language.rs           | 210 ++++++++++++++++---
 src/http/header/macros.rs                    | 138 +++++++-----
 src/http/header/mod.rs                       |  77 ++++---
 src/http/header/preference.rs                |  70 +++++++
 9 files changed, 469 insertions(+), 136 deletions(-)
 create mode 100644 src/http/header/preference.rs

diff --git a/CHANGES.md b/CHANGES.md
index 00bf85f27..36a56b828 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -1,6 +1,17 @@
 # Changes
 
 ## Unreleased - 2021-xx-xx
+### Added
+* Methods on `AcceptLanguage`: `ranked` and `preference`. [#2480]
+
+### Changed
+* Rename `Accept::{mime_precedence => ranked}`. [#2480]
+* Rename `Accept::{mime_preference => preference}`. [#2480]
+
+### Fixed
+* Accept wildcard `*` items in `AcceptLanguage`. [#2480]
+
+[#2480]: https://github.com/actix/actix-web/pull/2480
 
 
 ## 4.0.0-beta.13 - 2021-11-30
diff --git a/actix-http/src/header/mod.rs b/actix-http/src/header/mod.rs
index 721f4ea79..308cb0123 100644
--- a/actix-http/src/header/mod.rs
+++ b/actix-http/src/header/mod.rs
@@ -55,7 +55,7 @@ pub trait Header: IntoHeaderValue {
     fn name() -> HeaderName;
 
     /// Parse a header
-    fn parse<T: HttpMessage>(msg: &T) -> Result<Self, ParseError>;
+    fn parse<M: HttpMessage>(msg: &M) -> Result<Self, ParseError>;
 }
 
 /// Convert `http::HeaderMap` to our `HeaderMap`.
diff --git a/actix-http/src/header/shared/quality_item.rs b/actix-http/src/header/shared/quality_item.rs
index ad1f6877d..b9cca9112 100644
--- a/actix-http/src/header/shared/quality_item.rs
+++ b/actix-http/src/header/shared/quality_item.rs
@@ -1,8 +1,7 @@
 use std::{
     cmp,
     convert::{TryFrom, TryInto},
-    fmt,
-    str::{self, FromStr},
+    fmt, str,
 };
 
 use derive_more::{Display, Error};
@@ -83,16 +82,17 @@ impl TryFrom<f32> for Quality {
 /// in [RFC 7231 §5.3.1](https://datatracker.ietf.org/doc/html/rfc7231#section-5.3.1).
 #[derive(Clone, PartialEq, Debug)]
 pub struct QualityItem<T> {
-    /// The actual contents of the field.
+    /// The wrapped contents of the field.
     pub item: T,
+
     /// The quality (client or server preference) for the value.
     pub quality: Quality,
 }
 
 impl<T> QualityItem<T> {
-    /// Creates a new `QualityItem` from an item and a quality.
-    /// The item can be of any type.
-    /// The quality should be a value in the range [0, 1].
+    /// Constructs a new `QualityItem` from an item and a quality value.
+    ///
+    /// The item can be of any type. The quality should be a value in the range [0, 1].
     pub fn new(item: T, quality: Quality) -> QualityItem<T> {
         QualityItem { item, quality }
     }
@@ -116,7 +116,7 @@ impl<T: fmt::Display> fmt::Display for QualityItem<T> {
     }
 }
 
-impl<T: FromStr> FromStr for QualityItem<T> {
+impl<T: str::FromStr> str::FromStr for QualityItem<T> {
     type Err = ParseError;
 
     fn from_str(qitem_str: &str) -> Result<Self, Self::Err> {
@@ -128,6 +128,7 @@ impl<T: FromStr> FromStr for QualityItem<T> {
         let mut raw_item = qitem_str;
         let mut quality = 1f32;
 
+        // TODO: MSRV(1.52): use rsplit_once
         let parts: Vec<_> = qitem_str.rsplitn(2, ';').map(str::trim).collect();
 
         if parts.len() == 2 {
diff --git a/actix-http/src/header/utils.rs b/actix-http/src/header/utils.rs
index 94c5b6dcb..2168202b9 100644
--- a/actix-http/src/header/utils.rs
+++ b/actix-http/src/header/utils.rs
@@ -12,7 +12,8 @@ where
     I: Iterator<Item = &'a HeaderValue> + 'a,
     T: FromStr,
 {
-    let mut result = Vec::new();
+    let size_guess = all.size_hint().1.unwrap_or(2);
+    let mut result = Vec::with_capacity(size_guess);
 
     for h in all {
         let s = h.to_str().map_err(|_| ParseError::Header)?;
@@ -26,6 +27,7 @@ where
                 .filter_map(|x| x.trim().parse().ok()),
         )
     }
+
     Ok(result)
 }
 
@@ -34,10 +36,12 @@ where
 pub fn from_one_raw_str<T: FromStr>(val: Option<&HeaderValue>) -> Result<T, ParseError> {
     if let Some(line) = val {
         let line = line.to_str().map_err(|_| ParseError::Header)?;
+
         if !line.is_empty() {
             return T::from_str(line).or(Err(ParseError::Header));
         }
     }
+
     Err(ParseError::Header)
 }
 
@@ -48,13 +52,16 @@ where
     T: fmt::Display,
 {
     let mut iter = parts.iter();
+
     if let Some(part) = iter.next() {
         fmt::Display::fmt(part, f)?;
     }
+
     for part in iter {
         f.write_str(", ")?;
         fmt::Display::fmt(part, f)?;
     }
+
     Ok(())
 }
 
@@ -65,3 +72,25 @@ pub fn http_percent_encode(f: &mut fmt::Formatter<'_>, bytes: &[u8]) -> fmt::Res
     let encoded = percent_encoding::percent_encode(bytes, HTTP_VALUE);
     fmt::Display::fmt(&encoded, f)
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn comma_delimited_parsing() {
+        let headers = vec![];
+        let res: Vec<usize> = from_comma_delimited(headers.iter()).unwrap();
+        assert_eq!(res, vec![0; 0]);
+
+        let headers = vec![
+            HeaderValue::from_static(""),
+            HeaderValue::from_static(","),
+            HeaderValue::from_static("  "),
+            HeaderValue::from_static("1    ,"),
+            HeaderValue::from_static(""),
+        ];
+        let res: Vec<usize> = from_comma_delimited(headers.iter()).unwrap();
+        assert_eq!(res, vec![1]);
+    }
+}
diff --git a/src/http/header/accept.rs b/src/http/header/accept.rs
index 3c4d5f599..bc794c02c 100644
--- a/src/http/header/accept.rs
+++ b/src/http/header/accept.rs
@@ -77,7 +77,7 @@ crate::http::header::common_header! {
     ///     ])
     /// );
     /// ```
-    (Accept, header::ACCEPT) => (QualityItem<Mime>)+
+    (Accept, header::ACCEPT) => (QualityItem<Mime>)*
 
     test_parse_and_format {
         // Tests from the RFC
@@ -88,6 +88,7 @@ crate::http::header::common_header! {
                 QualityItem::new("audio/*".parse().unwrap(), q(200)),
                 qitem("audio/basic".parse().unwrap()),
                 ])));
+
         crate::http::header::common_header_test!(
             test2,
             vec![b"text/plain; q=0.5, text/html, text/x-dvi; q=0.8, text/x-c"],
@@ -99,6 +100,7 @@ crate::http::header::common_header! {
                     q(800)),
                 qitem("text/x-c".parse().unwrap()),
                 ])));
+
         // Custom tests
         crate::http::header::common_header_test!(
             test3,
@@ -154,7 +156,11 @@ impl Accept {
     /// [q-factor weighting] and specificity.
     ///
     /// [q-factor weighting]: https://datatracker.ietf.org/doc/html/rfc7231#section-5.3.2
-    pub fn mime_precedence(&self) -> Vec<Mime> {
+    pub fn ranked(&self) -> Vec<Mime> {
+        if self.is_empty() {
+            return vec![];
+        }
+
         let mut types = self.0.clone();
 
         // use stable sort so items with equal q-factor and specificity retain listed order
@@ -201,12 +207,29 @@ impl Accept {
     /// If no q-factors are provided, the first mime type is chosen. Note that items without
     /// q-factors are given the maximum preference value.
     ///
-    /// Returns `None` if contained list is empty.
+    /// As per the spec, will return [`Mime::STAR_STAR`] (indicating no preference) if the contained
+    /// list is empty.
     ///
     /// [q-factor weighting]: https://datatracker.ietf.org/doc/html/rfc7231#section-5.3.2
-    pub fn mime_preference(&self) -> Option<Mime> {
-        let types = self.mime_precedence();
-        types.first().cloned()
+    pub fn preference(&self) -> Mime {
+        use actix_http::header::q;
+
+        let mut max_item = None;
+        let mut max_pref = q(0);
+
+        // uses manual max lookup loop since we want the first occurrence in the case of same
+        // preference but `Iterator::max_by_key` would give us the last occurrence
+
+        for pref in &self.0 {
+            // only change if strictly greater
+            // equal items, even while unsorted, still have higher preference if they appear first
+            if pref.quality > max_pref {
+                max_pref = pref.quality;
+                max_item = Some(pref.item.clone());
+            }
+        }
+
+        max_item.unwrap_or(mime::STAR_STAR)
     }
 }
 
@@ -216,12 +239,12 @@ mod tests {
     use crate::http::header::q;
 
     #[test]
-    fn test_mime_precedence() {
+    fn ranking_precedence() {
         let test = Accept(vec![]);
-        assert!(test.mime_precedence().is_empty());
+        assert!(test.ranked().is_empty());
 
         let test = Accept(vec![qitem(mime::APPLICATION_JSON)]);
-        assert_eq!(test.mime_precedence(), vec!(mime::APPLICATION_JSON));
+        assert_eq!(test.ranked(), vec!(mime::APPLICATION_JSON));
 
         let test = Accept(vec![
             qitem(mime::TEXT_HTML),
@@ -230,7 +253,7 @@ mod tests {
             QualityItem::new(mime::STAR_STAR, q(0.8)),
         ]);
         assert_eq!(
-            test.mime_precedence(),
+            test.ranked(),
             vec![
                 mime::TEXT_HTML,
                 "application/xhtml+xml".parse().unwrap(),
@@ -245,20 +268,20 @@ mod tests {
             qitem(mime::IMAGE_PNG),
         ]);
         assert_eq!(
-            test.mime_precedence(),
+            test.ranked(),
             vec![mime::IMAGE_PNG, mime::IMAGE_STAR, mime::STAR_STAR]
         );
     }
 
     #[test]
-    fn test_mime_preference() {
+    fn preference_selection() {
         let test = Accept(vec![
             qitem(mime::TEXT_HTML),
             "application/xhtml+xml".parse().unwrap(),
             QualityItem::new("application/xml".parse().unwrap(), q(0.9)),
             QualityItem::new(mime::STAR_STAR, q(0.8)),
         ]);
-        assert_eq!(test.mime_preference(), Some(mime::TEXT_HTML));
+        assert_eq!(test.preference(), mime::TEXT_HTML);
 
         let test = Accept(vec![
             QualityItem::new("video/*".parse().unwrap(), q(0.8)),
@@ -267,6 +290,6 @@ mod tests {
             qitem(mime::IMAGE_SVG),
             QualityItem::new(mime::IMAGE_STAR, q(0.8)),
         ]);
-        assert_eq!(test.mime_preference(), Some(mime::IMAGE_PNG));
+        assert_eq!(test.preference(), mime::IMAGE_PNG);
     }
 }
diff --git a/src/http/header/accept_language.rs b/src/http/header/accept_language.rs
index a7b60e366..e96d1d13e 100644
--- a/src/http/header/accept_language.rs
+++ b/src/http/header/accept_language.rs
@@ -1,66 +1,224 @@
 use language_tags::LanguageTag;
 
-use super::{QualityItem, ACCEPT_LANGUAGE};
+use super::{common_header, Preference, QualityItem};
+use crate::http::header;
 
-crate::http::header::common_header! {
+common_header! {
     /// `Accept-Language` header, defined
     /// in [RFC 7231 §5.3.5](https://datatracker.ietf.org/doc/html/rfc7231#section-5.3.5)
     ///
-    /// The `Accept-Language` header field can be used by user agents to
-    /// indicate the set of natural languages that are preferred in the
-    /// response.
+    /// The `Accept-Language` header field can be used by user agents to indicate the set of natural
+    /// languages that are preferred in the response.
+    ///
+    /// The `Accept-Language` header is defined in
+    /// [RFC 7231 §5.3.5](https://datatracker.ietf.org/doc/html/rfc7231#section-5.3.5) using language
+    /// ranges defined in [RFC 4647 §2.1](https://datatracker.ietf.org/doc/html/rfc4647#section-2.1).
     ///
     /// # ABNF
-    ///
     /// ```text
     /// Accept-Language = 1#( language-range [ weight ] )
-    /// language-range  = <language-range, see [RFC4647], Section 2.1>
+    /// language-range  = (1*8ALPHA *("-" 1*8alphanum)) / "*"
+    /// alphanum        = ALPHA / DIGIT
+    /// weight          = OWS ";" OWS "q=" qvalue
+    /// qvalue          = ( "0" [ "." 0*3DIGIT ] )
+    ///                 / ( "1" [ "." 0*3("0") ] )
     /// ```
     ///
-    /// # Example values
-    /// * `da, en-gb;q=0.8, en;q=0.7`
-    /// * `en-us;q=1.0, en;q=0.5, fr`
+    /// # Example Values
+    /// - `da, en-gb;q=0.8, en;q=0.7`
+    /// - `en-us;q=1.0, en;q=0.5, fr`
+    /// - `fr-CH, fr;q=0.9, en;q=0.8, de;q=0.7, *;q=0.5`
     ///
     /// # Examples
-    ///
     /// ```
     /// use actix_web::HttpResponse;
-    /// use actix_web::http::header::{AcceptLanguage, LanguageTag, qitem};
+    /// use actix_web::http::header::{AcceptLanguage, qitem};
     ///
     /// let mut builder = HttpResponse::Ok();
-    /// let langtag = LanguageTag::parse("en-US").unwrap();
     /// builder.insert_header(
     ///     AcceptLanguage(vec![
-    ///         qitem(langtag),
+    ///         qitem("en-US".parse().unwrap())
     ///     ])
     /// );
     /// ```
     ///
     /// ```
     /// use actix_web::HttpResponse;
-    /// use actix_web::http::header::{AcceptLanguage, LanguageTag, QualityItem, q, qitem};
+    /// use actix_web::http::header::{AcceptLanguage, QualityItem, q, qitem};
     ///
     /// let mut builder = HttpResponse::Ok();
     /// builder.insert_header(
     ///     AcceptLanguage(vec![
-    ///         qitem(LanguageTag::parse("da").unwrap()),
-    ///         QualityItem::new(LanguageTag::parse("en-GB").unwrap(), q(800)),
-    ///         QualityItem::new(LanguageTag::parse("en").unwrap(), q(700)),
+    ///         qitem("da".parse().unwrap()),
+    ///         QualityItem::new("en-GB".parse().unwrap(), q(800)),
+    ///         QualityItem::new("en".parse().unwrap(), q(700)),
     ///     ])
     /// );
     /// ```
-    (AcceptLanguage, ACCEPT_LANGUAGE) => (QualityItem<LanguageTag>)+
+    (AcceptLanguage, header::ACCEPT_LANGUAGE) => (QualityItem<Preference<LanguageTag>>)*
 
-    test_accept_language {
-        // From the RFC
-        crate::http::header::common_header_test!(test1, vec![b"da, en-gb;q=0.8, en;q=0.7"]);
-        // Own test
-        crate::http::header::common_header_test!(
-            test2, vec![b"en-US, en; q=0.5, fr"],
+    parse_and_fmt_tests {
+        common_header_test!(no_headers, vec![b""; 0], Some(AcceptLanguage(vec![])));
+
+        common_header_test!(empty_header, vec![b""; 1], Some(AcceptLanguage(vec![])));
+
+        common_header_test!(
+            example_from_rfc,
+            vec![b"da, en-gb;q=0.8, en;q=0.7"]
+        );
+
+        common_header_test!(
+            not_ordered_by_weight,
+            vec![b"en-US, en; q=0.5, fr"],
             Some(AcceptLanguage(vec![
                 qitem("en-US".parse().unwrap()),
                 QualityItem::new("en".parse().unwrap(), q(500)),
                 qitem("fr".parse().unwrap()),
-        ])));
+            ]))
+        );
+
+        common_header_test!(
+            has_wildcard,
+            vec![b"fr-CH, fr; q=0.9, en; q=0.8, de; q=0.7, *; q=0.5"],
+            Some(AcceptLanguage(vec![
+                qitem("fr-CH".parse().unwrap()),
+                QualityItem::new("fr".parse().unwrap(), q(900)),
+                QualityItem::new("en".parse().unwrap(), q(800)),
+                QualityItem::new("de".parse().unwrap(), q(700)),
+                QualityItem::new("*".parse().unwrap(), q(500)),
+            ]))
+        );
+    }
+}
+
+impl AcceptLanguage {
+    /// Returns a sorted list of languages from highest to lowest precedence, accounting
+    /// for [q-factor weighting].
+    ///
+    /// [q-factor weighting]: https://datatracker.ietf.org/doc/html/rfc7231#section-5.3.2
+    pub fn ranked(&self) -> Vec<Preference<LanguageTag>> {
+        if self.0.is_empty() {
+            return vec![];
+        }
+
+        let mut types = self.0.clone();
+
+        // use stable sort so items with equal q-factor retain listed order
+        types.sort_by(|a, b| {
+            // sort by q-factor descending
+            b.quality.cmp(&a.quality)
+        });
+
+        types.into_iter().map(|qitem| qitem.item).collect()
+    }
+
+    /// Extracts the most preferable language, accounting for [q-factor weighting].
+    ///
+    /// If no q-factors are provided, the first language is chosen. Note that items without
+    /// q-factors are given the maximum preference value.
+    ///
+    /// As per the spec, returns [`Preference::Any`] if contained list is empty.
+    ///
+    /// [q-factor weighting]: https://datatracker.ietf.org/doc/html/rfc7231#section-5.3.2
+    pub fn preference(&self) -> Preference<LanguageTag> {
+        use actix_http::header::q;
+
+        let mut max_item = None;
+        let mut max_pref = q(0);
+
+        // uses manual max lookup loop since we want the first occurrence in the case of same
+        // preference but `Iterator::max_by_key` would give us the last occurrence
+
+        for pref in &self.0 {
+            // only change if strictly greater
+            // equal items, even while unsorted, still have higher preference if they appear first
+            if pref.quality > max_pref {
+                max_pref = pref.quality;
+                max_item = Some(pref.item.clone());
+            }
+        }
+
+        max_item.unwrap_or(Preference::Any)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::http::header::*;
+
+    #[test]
+    fn ranking_precedence() {
+        let test = AcceptLanguage(vec![]);
+        assert!(test.ranked().is_empty());
+
+        let test = AcceptLanguage(vec![qitem("fr-CH".parse().unwrap())]);
+        assert_eq!(test.ranked(), vec!("fr-CH".parse().unwrap()));
+
+        let test = AcceptLanguage(vec![
+            QualityItem::new("fr".parse().unwrap(), q(900)),
+            QualityItem::new("fr-CH".parse().unwrap(), q(1000)),
+            QualityItem::new("en".parse().unwrap(), q(800)),
+            QualityItem::new("*".parse().unwrap(), q(500)),
+            QualityItem::new("de".parse().unwrap(), q(700)),
+        ]);
+        assert_eq!(
+            test.ranked(),
+            vec![
+                "fr-CH".parse().unwrap(),
+                "fr".parse().unwrap(),
+                "en".parse().unwrap(),
+                "de".parse().unwrap(),
+                "*".parse().unwrap(),
+            ]
+        );
+
+        let test = AcceptLanguage(vec![
+            qitem("fr".parse().unwrap()),
+            qitem("fr-CH".parse().unwrap()),
+            qitem("en".parse().unwrap()),
+            qitem("*".parse().unwrap()),
+            qitem("de".parse().unwrap()),
+        ]);
+        assert_eq!(
+            test.ranked(),
+            vec![
+                "fr".parse().unwrap(),
+                "fr-CH".parse().unwrap(),
+                "en".parse().unwrap(),
+                "*".parse().unwrap(),
+                "de".parse().unwrap(),
+            ]
+        );
+    }
+
+    #[test]
+    fn preference_selection() {
+        let test = AcceptLanguage(vec![
+            QualityItem::new("fr".parse().unwrap(), q(900)),
+            QualityItem::new("fr-CH".parse().unwrap(), q(1000)),
+            QualityItem::new("en".parse().unwrap(), q(800)),
+            QualityItem::new("*".parse().unwrap(), q(500)),
+            QualityItem::new("de".parse().unwrap(), q(700)),
+        ]);
+        assert_eq!(
+            test.preference(),
+            Preference::Specific("fr-CH".parse().unwrap())
+        );
+
+        let test = AcceptLanguage(vec![
+            qitem("fr".parse().unwrap()),
+            qitem("fr-CH".parse().unwrap()),
+            qitem("en".parse().unwrap()),
+            qitem("*".parse().unwrap()),
+            qitem("de".parse().unwrap()),
+        ]);
+        assert_eq!(
+            test.preference(),
+            Preference::Specific("fr".parse().unwrap())
+        );
+
+        let test = AcceptLanguage(vec![]);
+        assert_eq!(test.preference(), Preference::Any);
     }
 }
diff --git a/src/http/header/macros.rs b/src/http/header/macros.rs
index 419d4fb6e..7fed7f286 100644
--- a/src/http/header/macros.rs
+++ b/src/http/header/macros.rs
@@ -1,33 +1,36 @@
+// TODO: replace with derive_more impl
 macro_rules! common_header_deref {
     ($from:ty => $to:ty) => {
-        impl ::std::ops::Deref for $from {
+        impl ::core::ops::Deref for $from {
             type Target = $to;
 
             #[inline]
-            fn deref(&self) -> &$to {
+            fn deref(&self) -> &Self::Target {
                 &self.0
             }
         }
 
-        impl ::std::ops::DerefMut for $from {
+        impl ::core::ops::DerefMut for $from {
             #[inline]
-            fn deref_mut(&mut self) -> &mut $to {
+            fn deref_mut(&mut self) -> &mut Self::Target {
                 &mut self.0
             }
         }
     };
 }
 
+/// Sets up a test module with some useful imports for use with [`common_header_test!`].
 macro_rules! common_header_test_module {
     ($id:ident, $tm:ident{$($tf:item)*}) => {
-        #[allow(unused_imports)]
         #[cfg(test)]
         mod $tm {
+            #![allow(unused_imports)]
+
             use std::str;
             use actix_http::http::Method;
             use mime::*;
             use $crate::http::header::*;
-            use super::$id as HeaderField;
+            use super::{$id as HeaderField, *};
             $($tf)*
         }
     }
@@ -42,14 +45,19 @@ macro_rules! common_header_test {
 
             let raw = $raw;
             let a: Vec<Vec<u8>> = raw.iter().map(|x| x.to_vec()).collect();
+
             let mut req = test::TestRequest::default();
+
             for item in a {
                 req = req.insert_header((HeaderField::name(), item)).take();
             }
+
             let req = req.finish();
             let value = HeaderField::parse(&req);
+
             let result = format!("{}", value.unwrap());
             let expected = String::from_utf8(raw[0].to_vec()).unwrap();
+
             let result_cmp: Vec<String> = result
                 .to_ascii_lowercase()
                 .split(' ')
@@ -60,10 +68,12 @@ macro_rules! common_header_test {
                 .split(' ')
                 .map(|x| x.to_owned())
                 .collect();
+
             assert_eq!(result_cmp.concat(), expected_cmp.concat());
         }
     };
-    ($id:ident, $raw:expr, $typed:expr) => {
+
+    ($id:ident, $raw:expr, $exp:expr) => {
         #[test]
         fn $id() {
             use actix_http::test;
@@ -75,26 +85,35 @@ macro_rules! common_header_test {
             }
             let req = req.finish();
             let val = HeaderField::parse(&req);
-            let typed: Option<HeaderField> = $typed;
-            // Test parsing
-            assert_eq!(val.ok(), typed);
-            // Test formatting
-            if typed.is_some() {
+            let exp: Option<HeaderField> = $exp;
+
+            println!("req: {:?}", &req);
+            println!("val: {:?}", &val);
+            println!("exp: {:?}", &exp);
+
+            // test parsing
+            assert_eq!(val.ok(), exp);
+
+            // test formatting
+            if let Some(exp) = exp {
                 let raw = &($raw)[..];
                 let mut iter = raw.iter().map(|b| str::from_utf8(&b[..]).unwrap());
                 let mut joined = String::new();
-                joined.push_str(iter.next().unwrap());
-                for s in iter {
-                    joined.push_str(", ");
+                if let Some(s) = iter.next() {
                     joined.push_str(s);
+                    for s in iter {
+                        joined.push_str(", ");
+                        joined.push_str(s);
+                    }
                 }
-                assert_eq!(format!("{}", typed.unwrap()), joined);
+                assert_eq!(format!("{}", exp), joined);
             }
         }
     };
 }
 
 macro_rules! common_header {
+    // TODO: these docs are wrong, there's no $n or $nn
     // $a:meta: Attributes associated with the header item (usually docs)
     // $id:ident: Identifier of the header
     // $n:expr: Lowercase name of the header
@@ -111,92 +130,100 @@ macro_rules! common_header {
             fn name() -> $crate::http::header::HeaderName {
                 $name
             }
+
             #[inline]
-            fn parse<T>(msg: &T) -> Result<Self, $crate::error::ParseError>
-                where T: $crate::HttpMessage
-            {
-                $crate::http::header::from_comma_delimited(
-                    msg.headers().get_all(Self::name())).map($id)
+            fn parse<M: $crate::HttpMessage>(msg: &M) -> Result<Self, $crate::error::ParseError> {
+                let headers = msg.headers().get_all(Self::name());
+                $crate::http::header::from_comma_delimited(headers).map($id)
             }
         }
-        impl std::fmt::Display for $id {
+
+        impl ::core::fmt::Display for $id {
             #[inline]
-            fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> ::std::fmt::Result {
+            fn fmt(&self, f: &mut ::core::fmt::Formatter<'_>) -> ::core::fmt::Result {
                 $crate::http::header::fmt_comma_delimited(f, &self.0[..])
             }
         }
+
         impl $crate::http::header::IntoHeaderValue for $id {
             type Error = $crate::http::header::InvalidHeaderValue;
 
             fn try_into_value(self) -> Result<$crate::http::header::HeaderValue, Self::Error> {
-                use std::fmt::Write;
+                use ::core::fmt::Write;
                 let mut writer = $crate::http::header::Writer::new();
                 let _ = write!(&mut writer, "{}", self);
                 $crate::http::header::HeaderValue::from_maybe_shared(writer.take())
             }
         }
     };
+
     // List header, one or more items
     ($(#[$a:meta])*($id:ident, $name:expr) => ($item:ty)+) => {
         $(#[$a])*
         #[derive(Clone, Debug, PartialEq)]
         pub struct $id(pub Vec<$item>);
+
         crate::http::header::common_header_deref!($id => Vec<$item>);
+
         impl $crate::http::header::Header for $id {
             #[inline]
             fn name() -> $crate::http::header::HeaderName {
                 $name
             }
             #[inline]
-            fn parse<T>(msg: &T) -> Result<Self, $crate::error::ParseError>
-                where T: $crate::HttpMessage
-            {
+            fn parse<M: $crate::HttpMessage>(msg: &M) -> Result<Self, $crate::error::ParseError> {
                 $crate::http::header::from_comma_delimited(
                     msg.headers().get_all(Self::name())).map($id)
             }
         }
-        impl std::fmt::Display for $id {
+
+        impl ::core::fmt::Display for $id {
             #[inline]
-            fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+            fn fmt(&self, f: &mut ::core::fmt::Formatter<'_>) -> ::core::fmt::Result {
                 $crate::http::header::fmt_comma_delimited(f, &self.0[..])
             }
         }
+
         impl $crate::http::header::IntoHeaderValue for $id {
             type Error = $crate::http::header::InvalidHeaderValue;
 
             fn try_into_value(self) -> Result<$crate::http::header::HeaderValue, Self::Error> {
-                use std::fmt::Write;
+                use ::core::fmt::Write;
                 let mut writer = $crate::http::header::Writer::new();
                 let _ = write!(&mut writer, "{}", self);
                 $crate::http::header::HeaderValue::from_maybe_shared(writer.take())
             }
         }
     };
+
     // Single value header
     ($(#[$a:meta])*($id:ident, $name:expr) => [$value:ty]) => {
         $(#[$a])*
         #[derive(Clone, Debug, PartialEq)]
         pub struct $id(pub $value);
+
         crate::http::header::common_header_deref!($id => $value);
+
         impl $crate::http::header::Header for $id {
             #[inline]
             fn name() -> $crate::http::header::HeaderName {
                 $name
             }
+
             #[inline]
-            fn parse<T>(msg: &T) -> Result<Self, $crate::error::ParseError>
-                where T: $crate::HttpMessage
-            {
-                $crate::http::header::from_one_raw_str(
-                    msg.headers().get(Self::name())).map($id)
+            fn parse<M: $crate::HttpMessage>(msg: &M) -> Result<Self, $crate::error::ParseError> {
+                let header = msg.headers().get(Self::name());
+                $crate::http::header::from_one_raw_str(header).map($id)
             }
         }
-        impl std::fmt::Display for $id {
+
+        impl ::core::fmt::Display for $id {
             #[inline]
-            fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-                std::fmt::Display::fmt(&self.0, f)
+            fn fmt(&self, f: &mut ::core::fmt::Formatter<'_>) -> ::core::fmt::Result {
+                ::core::fmt::Display::fmt(&self.0, f)
             }
         }
+
         impl $crate::http::header::IntoHeaderValue for $id {
             type Error = $crate::http::header::InvalidHeaderValue;
 
@@ -205,6 +232,7 @@ macro_rules! common_header {
             }
         }
     };
+
     // List header, one or more items with "*" option
     ($(#[$a:meta])*($id:ident, $name:expr) => {Any / ($item:ty)+}) => {
         $(#[$a])*
@@ -215,42 +243,46 @@ macro_rules! common_header {
             /// Only the listed items are a match
             Items(Vec<$item>),
         }
+
         impl $crate::http::header::Header for $id {
             #[inline]
             fn name() -> $crate::http::header::HeaderName {
                 $name
             }
-            #[inline]
-            fn parse<T>(msg: &T) -> Result<Self, $crate::error::ParseError>
-                where T: $crate::HttpMessage
-            {
-                let any = msg.headers().get(Self::name()).and_then(|hdr| {
-                    hdr.to_str().ok().and_then(|hdr| Some(hdr.trim() == "*"))});
 
-                if let Some(true) = any {
+            #[inline]
+            fn parse<M: $crate::HttpMessage>(msg: &M) -> Result<Self, $crate::error::ParseError> {
+                let is_any = msg
+                    .headers()
+                    .get(Self::name())
+                    .and_then(|hdr| hdr.to_str().ok())
+                    .map(|hdr| hdr.trim() == "*");
+
+                if let Some(true) = is_any {
                     Ok($id::Any)
                 } else {
-                    Ok($id::Items(
-                        $crate::http::header::from_comma_delimited(
-                            msg.headers().get_all(Self::name()))?))
+                    let headers = msg.headers().get_all(Self::name());
+                    Ok($id::Items($crate::http::header::from_comma_delimited(headers)?))
                 }
             }
         }
-        impl std::fmt::Display for $id {
+
+        impl ::core::fmt::Display for $id {
             #[inline]
-            fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+            fn fmt(&self, f: &mut ::core::fmt::Formatter<'_>) -> ::core::fmt::Result {
                 match *self {
                     $id::Any => f.write_str("*"),
-                    $id::Items(ref fields) => $crate::http::header::fmt_comma_delimited(
-                        f, &fields[..])
+                    $id::Items(ref fields) =>
+                        $crate::http::header::fmt_comma_delimited(f, &fields[..])
                 }
             }
         }
+
         impl $crate::http::header::IntoHeaderValue for $id {
             type Error = $crate::http::header::InvalidHeaderValue;
 
             fn try_into_value(self) -> Result<$crate::http::header::HeaderValue, Self::Error> {
-                use std::fmt::Write;
+                use ::core::fmt::Write;
                 let mut writer = $crate::http::header::Writer::new();
                 let _ = write!(&mut writer, "{}", self);
                 $crate::http::header::HeaderValue::from_maybe_shared(writer.take())
diff --git a/src/http/header/mod.rs b/src/http/header/mod.rs
index 79ba5772b..45d5b8d1a 100644
--- a/src/http/header/mod.rs
+++ b/src/http/header/mod.rs
@@ -1,15 +1,52 @@
 //! A Collection of Header implementations for common HTTP Headers.
 //!
-//! ## Mime
-//!
+//! ## Mime Types
 //! Several header fields use MIME values for their contents. Keeping with the strongly-typed theme,
 //! the [mime] crate is used in such headers as [`ContentType`] and [`Accept`].
 
-use bytes::{Bytes, BytesMut};
 use std::fmt;
 
-pub use self::accept_charset::AcceptCharset;
+use bytes::{Bytes, BytesMut};
+
+// re-export from actix-http
+// - header name / value types
+// - relevant traits for converting to header name / value
+// - all const header names
+// - header map
+// - the few typed headers from actix-http
+// - header parsing utils
 pub use actix_http::http::header::*;
+
+mod accept_charset;
+// mod accept_encoding;
+mod accept;
+mod accept_language;
+mod allow;
+mod cache_control;
+mod content_disposition;
+mod content_language;
+mod content_range;
+mod content_type;
+mod date;
+mod encoding;
+mod entity;
+mod etag;
+mod expires;
+mod if_match;
+mod if_modified_since;
+mod if_none_match;
+mod if_range;
+mod if_unmodified_since;
+mod last_modified;
+mod macros;
+mod preference;
+// mod range;
+
+#[cfg(test)]
+pub(crate) use macros::common_header_test;
+pub(crate) use macros::{common_header, common_header_deref, common_header_test_module};
+
+pub use self::accept_charset::AcceptCharset;
 //pub use self::accept_encoding::AcceptEncoding;
 pub use self::accept::Accept;
 pub use self::accept_language::AcceptLanguage;
@@ -30,11 +67,10 @@ pub use self::if_none_match::IfNoneMatch;
 pub use self::if_range::IfRange;
 pub use self::if_unmodified_since::IfUnmodifiedSince;
 pub use self::last_modified::LastModified;
+pub use self::preference::Preference;
 //pub use self::range::{Range, ByteRangeSpec};
-pub(crate) use actix_http::http::header::{
-    fmt_comma_delimited, from_comma_delimited, from_one_raw_str,
-};
 
+/// Format writer ([`fmt::Write`]) for a [`BytesMut`].
 #[derive(Debug, Default)]
 struct Writer {
     buf: BytesMut,
@@ -62,30 +98,3 @@ impl fmt::Write for Writer {
         fmt::write(self, args)
     }
 }
-
-mod accept_charset;
-// mod accept_encoding;
-mod accept;
-mod accept_language;
-mod allow;
-mod cache_control;
-mod content_disposition;
-mod content_language;
-mod content_range;
-mod content_type;
-mod date;
-mod encoding;
-mod entity;
-mod etag;
-mod expires;
-mod if_match;
-mod if_modified_since;
-mod if_none_match;
-mod if_range;
-mod if_unmodified_since;
-mod last_modified;
-
-mod macros;
-#[cfg(test)]
-pub(crate) use macros::common_header_test;
-pub(crate) use macros::{common_header, common_header_deref, common_header_test_module};
diff --git a/src/http/header/preference.rs b/src/http/header/preference.rs
new file mode 100644
index 000000000..979fc7720
--- /dev/null
+++ b/src/http/header/preference.rs
@@ -0,0 +1,70 @@
+use std::{
+    fmt::{self, Write as _},
+    str,
+};
+
+/// A wrapper for types used in header values where wildcard (`*`) items are allowed but the
+/// underlying type does not support them.
+///
+/// For example, we use the `language-tags` crate for the [`AcceptLanguage`](super::AcceptLanguage)
+/// typed header but it does not parse `*` successfully. On the other hand, the `mime` crate, used
+/// for [`Accept`](super::Accept), has first-party support for wildcard items so this wrapper is not
+/// used in those header types.
+#[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Hash)]
+pub enum Preference<T> {
+    /// A wildcard value.
+    Any,
+
+    /// A valid `T`.
+    Specific(T),
+}
+
+impl<T> Preference<T> {
+    /// Returns true if preference is the any/wildcard (`*`) value.
+    pub fn is_any(&self) -> bool {
+        matches!(self, Self::Any)
+    }
+
+    /// Returns true if preference is the specific item (`T`) variant.
+    pub fn is_specific(&self) -> bool {
+        matches!(self, Self::Specific(_))
+    }
+
+    /// Returns reference to value in `Specific` variant, if it is set.
+    pub fn item(&self) -> Option<&T> {
+        match self {
+            Preference::Specific(ref item) => Some(item),
+            Preference::Any => None,
+        }
+    }
+
+    /// Consumes the container, returning the value in the `Specific` variant, if it is set.
+    pub fn into_item(self) -> Option<T> {
+        match self {
+            Preference::Specific(item) => Some(item),
+            Preference::Any => None,
+        }
+    }
+}
+
+impl<T: fmt::Display> fmt::Display for Preference<T> {
+    #[inline]
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            Preference::Any => f.write_char('*'),
+            Preference::Specific(item) => fmt::Display::fmt(item, f),
+        }
+    }
+}
+
+impl<T: str::FromStr> str::FromStr for Preference<T> {
+    type Err = T::Err;
+
+    #[inline]
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        match s.trim() {
+            "*" => Ok(Self::Any),
+            other => other.parse().map(Preference::Specific),
+        }
+    }
+}

From 2a72bdae0991c49203b9359eade740e4de0881ef Mon Sep 17 00:00:00 2001
From: Rob Ede <robjtede@icloud.com>
Date: Thu, 2 Dec 2021 15:25:39 +0000
Subject: [PATCH 2/3] improve typed header macro (#2481)

---
 actix-http/src/header/shared/charset.rs      |  2 +-
 actix-http/src/header/shared/extended.rs     |  2 +-
 actix-http/src/header/shared/http_date.rs    |  2 +-
 actix-http/src/header/shared/quality_item.rs |  4 +-
 actix-web-codegen/src/lib.rs                 |  4 +-
 src/http/header/accept.rs                    |  2 +-
 src/http/header/accept_charset.rs            |  2 +-
 src/http/header/accept_encoding.rs           |  8 ++-
 src/http/header/accept_language.rs           |  4 +-
 src/http/header/allow.rs                     |  2 +-
 src/http/header/any_or_some.rs               | 70 ++++++++++++++++++
 src/http/header/cache_control.rs             | 10 +--
 src/http/header/content_disposition.rs       |  2 +-
 src/http/header/content_language.rs          |  7 +-
 src/http/header/content_range.rs             |  4 +-
 src/http/header/content_type.rs              |  4 +-
 src/http/header/date.rs                      |  2 +-
 src/http/header/entity.rs                    |  2 +-
 src/http/header/etag.rs                      |  2 +-
 src/http/header/expires.rs                   |  2 +-
 src/http/header/if_match.rs                  |  6 +-
 src/http/header/if_modified_since.rs         |  2 +-
 src/http/header/if_none_match.rs             |  2 +-
 src/http/header/if_range.rs                  |  7 +-
 src/http/header/if_unmodified_since.rs       |  2 +-
 src/http/header/last_modified.rs             |  2 +-
 src/http/header/macros.rs                    | 74 ++++++--------------
 src/http/header/mod.rs                       |  2 +-
 src/http/header/range.rs                     | 13 ++--
 29 files changed, 147 insertions(+), 100 deletions(-)
 create mode 100644 src/http/header/any_or_some.rs

diff --git a/actix-http/src/header/shared/charset.rs b/actix-http/src/header/shared/charset.rs
index 109c02bd1..1e77e1be8 100644
--- a/actix-http/src/header/shared/charset.rs
+++ b/actix-http/src/header/shared/charset.rs
@@ -7,7 +7,7 @@ use self::Charset::*;
 /// The string representation is normalized to upper case.
 ///
 /// See <http://www.iana.org/assignments/character-sets/character-sets.xhtml>.
-#[derive(Clone, Debug, PartialEq)]
+#[derive(Debug, Clone, PartialEq, Eq)]
 #[allow(non_camel_case_types)]
 pub enum Charset {
     /// US ASCII
diff --git a/actix-http/src/header/shared/extended.rs b/actix-http/src/header/shared/extended.rs
index 5ff5c8b34..b2cf1d754 100644
--- a/actix-http/src/header/shared/extended.rs
+++ b/actix-http/src/header/shared/extended.rs
@@ -31,7 +31,7 @@ pub struct ExtendedValue {
 ///
 /// ## ABNF
 ///
-/// ```text
+/// ```plain
 /// ext-value     = charset  "'" [ language ] "'" value-chars
 ///               ; like RFC 2231's <extended-initial-value>
 ///               ; (see [RFC 2231 §7])
diff --git a/actix-http/src/header/shared/http_date.rs b/actix-http/src/header/shared/http_date.rs
index 3441f90af..8dbdf4a62 100644
--- a/actix-http/src/header/shared/http_date.rs
+++ b/actix-http/src/header/shared/http_date.rs
@@ -8,7 +8,7 @@ use crate::{
     helpers::MutWriter,
 };
 
-/// A timestamp with HTTP formatting and parsing.
+/// A timestamp with HTTP-style formatting and parsing.
 #[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord)]
 pub struct HttpDate(SystemTime);
 
diff --git a/actix-http/src/header/shared/quality_item.rs b/actix-http/src/header/shared/quality_item.rs
index b9cca9112..9b170f01a 100644
--- a/actix-http/src/header/shared/quality_item.rs
+++ b/actix-http/src/header/shared/quality_item.rs
@@ -27,7 +27,7 @@ const MAX_FLOAT_QUALITY: f32 = 1.0;
 ///
 /// [RFC 7231 §5.3.1](https://datatracker.ietf.org/doc/html/rfc7231#section-5.3.1) gives more
 /// information on quality values in HTTP header fields.
-#[derive(Copy, Clone, Debug, PartialEq, Eq, PartialOrd, Ord)]
+#[derive(Debug, Copy, Clone, PartialEq, Eq, PartialOrd, Ord)]
 pub struct Quality(u16);
 
 impl Quality {
@@ -80,7 +80,7 @@ impl TryFrom<f32> for Quality {
 
 /// Represents an item with a quality value as defined
 /// in [RFC 7231 §5.3.1](https://datatracker.ietf.org/doc/html/rfc7231#section-5.3.1).
-#[derive(Clone, PartialEq, Debug)]
+#[derive(Debug, Clone, PartialEq, Eq)]
 pub struct QualityItem<T> {
     /// The wrapped contents of the field.
     pub item: T,
diff --git a/actix-web-codegen/src/lib.rs b/actix-web-codegen/src/lib.rs
index 85faf6bca..cebf9e5fb 100644
--- a/actix-web-codegen/src/lib.rs
+++ b/actix-web-codegen/src/lib.rs
@@ -66,7 +66,7 @@ mod route;
 /// Creates resource handler, allowing multiple HTTP method guards.
 ///
 /// # Syntax
-/// ```text
+/// ```plain
 /// #[route("path", method="HTTP_METHOD"[, attributes])]
 /// ```
 ///
@@ -112,7 +112,7 @@ concat!("
 Creates route handler with `actix_web::guard::", stringify!($variant), "`.
 
 # Syntax
-```text
+```plain
 #[", stringify!($method), r#"("path"[, attributes])]
 ```
 
diff --git a/src/http/header/accept.rs b/src/http/header/accept.rs
index bc794c02c..a0c98547d 100644
--- a/src/http/header/accept.rs
+++ b/src/http/header/accept.rs
@@ -16,7 +16,7 @@ crate::http::header::common_header! {
     /// in-line image
     ///
     /// # ABNF
-    /// ```text
+    /// ```plain
     /// Accept = #( media-range [ accept-params ] )
     ///
     /// media-range    = ( "*/*"
diff --git a/src/http/header/accept_charset.rs b/src/http/header/accept_charset.rs
index fb21c5ac2..5577ab604 100644
--- a/src/http/header/accept_charset.rs
+++ b/src/http/header/accept_charset.rs
@@ -12,7 +12,7 @@ crate::http::header::common_header! {
     /// those charsets.
     ///
     /// # ABNF
-    /// ```text
+    /// ```plain
     /// Accept-Charset = 1#( ( charset / "*" ) [ weight ] )
     /// ```
     ///
diff --git a/src/http/header/accept_encoding.rs b/src/http/header/accept_encoding.rs
index f7375a1e4..0440153ae 100644
--- a/src/http/header/accept_encoding.rs
+++ b/src/http/header/accept_encoding.rs
@@ -1,3 +1,5 @@
+// TODO: reinstate module
+
 use header::{Encoding, QualityItem};
 
 header! {
@@ -11,7 +13,7 @@ header! {
     /// preferred.
     ///
     /// # ABNF
-    /// ```text
+    /// ```plain
     /// Accept-Encoding  = #( codings [ weight ] )
     /// codings          = content-coding / "identity" / "*"
     /// ```
@@ -59,15 +61,17 @@ header! {
     ///     ])
     /// );
     /// ```
-    (AcceptEncoding, "Accept-Encoding") => (QualityItem<Encoding>)*
+    (AcceptEncoding, header::ACCEPT_ENCODING) => (QualityItem<Encoding>)*
 
     test_parse_and_format {
         // From the RFC
         crate::http::header::common_header_test!(test1, vec![b"compress, gzip"]);
         crate::http::header::common_header_test!(test2, vec![b""], Some(AcceptEncoding(vec![])));
         crate::http::header::common_header_test!(test3, vec![b"*"]);
+
         // Note: Removed quality 1 from gzip
         crate::http::header::common_header_test!(test4, vec![b"compress;q=0.5, gzip"]);
+
         // Note: Removed quality 1 from gzip
         crate::http::header::common_header_test!(test5, vec![b"gzip, identity; q=0.5, *;q=0"]);
     }
diff --git a/src/http/header/accept_language.rs b/src/http/header/accept_language.rs
index e96d1d13e..fb1637eb1 100644
--- a/src/http/header/accept_language.rs
+++ b/src/http/header/accept_language.rs
@@ -15,7 +15,7 @@ common_header! {
     /// ranges defined in [RFC 4647 §2.1](https://datatracker.ietf.org/doc/html/rfc4647#section-2.1).
     ///
     /// # ABNF
-    /// ```text
+    /// ```plain
     /// Accept-Language = 1#( language-range [ weight ] )
     /// language-range  = (1*8ALPHA *("-" 1*8alphanum)) / "*"
     /// alphanum        = ALPHA / DIGIT
@@ -57,7 +57,7 @@ common_header! {
     /// ```
     (AcceptLanguage, header::ACCEPT_LANGUAGE) => (QualityItem<Preference<LanguageTag>>)*
 
-    parse_and_fmt_tests {
+    test_parse_and_format {
         common_header_test!(no_headers, vec![b""; 0], Some(AcceptLanguage(vec![])));
 
         common_header_test!(empty_header, vec![b""; 1], Some(AcceptLanguage(vec![])));
diff --git a/src/http/header/allow.rs b/src/http/header/allow.rs
index 2546ce3a8..c8cc153e8 100644
--- a/src/http/header/allow.rs
+++ b/src/http/header/allow.rs
@@ -12,7 +12,7 @@ crate::http::header::common_header! {
     /// with the resource.
     ///
     /// # ABNF
-    /// ```text
+    /// ```plain
     /// Allow = #method
     /// ```
     ///
diff --git a/src/http/header/any_or_some.rs b/src/http/header/any_or_some.rs
new file mode 100644
index 000000000..e5a37e495
--- /dev/null
+++ b/src/http/header/any_or_some.rs
@@ -0,0 +1,70 @@
+use std::{
+    fmt::{self, Write as _},
+    str,
+};
+
+/// A wrapper for types used in header values where wildcard (`*`) items are allowed but the
+/// underlying type does not support them.
+///
+/// For example, we use the `language-tags` crate for the [`AcceptLanguage`](super::AcceptLanguage)
+/// typed header but it does parse `*` successfully. On the other hand, the `mime` crate, used for
+/// [`Accept`](super::Accept), has first-party support for wildcard items so this wrapper is not
+/// used in those header types.
+#[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Hash)]
+pub enum AnyOrSome<T> {
+    /// A wildcard value.
+    Any,
+
+    /// A valid `T`.
+    Item(T),
+}
+
+impl<T> AnyOrSome<T> {
+    /// Returns true if item is wildcard (`*`) variant.
+    pub fn is_any(&self) -> bool {
+        matches!(self, Self::Any)
+    }
+
+    /// Returns true if item is a valid item (`T`) variant.
+    pub fn is_item(&self) -> bool {
+        matches!(self, Self::Item(_))
+    }
+
+    /// Returns reference to value in `Item` variant, if it is set.
+    pub fn item(&self) -> Option<&T> {
+        match self {
+            AnyOrSome::Item(ref item) => Some(item),
+            AnyOrSome::Any => None,
+        }
+    }
+
+    /// Consumes the container, returning the value in the `Item` variant, if it is set.
+    pub fn into_item(self) -> Option<T> {
+        match self {
+            AnyOrSome::Item(item) => Some(item),
+            AnyOrSome::Any => None,
+        }
+    }
+}
+
+impl<T: fmt::Display> fmt::Display for AnyOrSome<T> {
+    #[inline]
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            AnyOrSome::Any => f.write_char('*'),
+            AnyOrSome::Item(item) => fmt::Display::fmt(item, f),
+        }
+    }
+}
+
+impl<T: str::FromStr> str::FromStr for AnyOrSome<T> {
+    type Err = T::Err;
+
+    #[inline]
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        match s.trim() {
+            "*" => Ok(Self::Any),
+            other => other.parse().map(AnyOrSome::Item),
+        }
+    }
+}
diff --git a/src/http/header/cache_control.rs b/src/http/header/cache_control.rs
index c5ac9e798..27cf30ce4 100644
--- a/src/http/header/cache_control.rs
+++ b/src/http/header/cache_control.rs
@@ -1,6 +1,8 @@
 use std::fmt::{self, Write};
 use std::str::FromStr;
 
+use derive_more::{Deref, DerefMut};
+
 use super::{fmt_comma_delimited, from_comma_delimited, Header, IntoHeaderValue, Writer};
 
 use crate::http::header;
@@ -14,7 +16,7 @@ use crate::http::header;
 /// not imply that the same directive is to be given in the response.
 ///
 /// # ABNF
-/// ```text
+/// ```plain
 /// Cache-Control   = 1#cache-directive
 /// cache-directive = token [ "=" ( token / quoted-string ) ]
 /// ```
@@ -46,11 +48,9 @@ use crate::http::header;
 ///     CacheDirective::Extension("foo".to_owned(), Some("bar".to_owned())),
 /// ]));
 /// ```
-#[derive(PartialEq, Clone, Debug)]
+#[derive(Debug, Clone, PartialEq, Eq, Deref, DerefMut)]
 pub struct CacheControl(pub Vec<CacheDirective>);
 
-crate::http::header::common_header_deref!(CacheControl => Vec<CacheDirective>);
-
 // TODO: this could just be the crate::http::header::common_header! macro
 impl Header for CacheControl {
     fn name() -> header::HeaderName {
@@ -88,7 +88,7 @@ impl IntoHeaderValue for CacheControl {
 }
 
 /// `CacheControl` contains a list of these directives.
-#[derive(PartialEq, Clone, Debug)]
+#[derive(Debug, Clone, PartialEq, Eq)]
 pub enum CacheDirective {
     /// "no-cache"
     NoCache,
diff --git a/src/http/header/content_disposition.rs b/src/http/header/content_disposition.rs
index 79fdb7658..945a58f7f 100644
--- a/src/http/header/content_disposition.rs
+++ b/src/http/header/content_disposition.rs
@@ -220,7 +220,7 @@ impl DispositionParam {
 /// itself, *Content-Disposition* has no effect.
 ///
 /// # ABNF
-/// ```text
+/// ```plain
 /// content-disposition = "Content-Disposition" ":"
 ///                       disposition-type *( ";" disposition-parm )
 ///
diff --git a/src/http/header/content_language.rs b/src/http/header/content_language.rs
index 0f428ad35..39ca8da56 100644
--- a/src/http/header/content_language.rs
+++ b/src/http/header/content_language.rs
@@ -1,7 +1,8 @@
-use super::{QualityItem, CONTENT_LANGUAGE};
 use language_tags::LanguageTag;
 
-crate::http::header::common_header! {
+use super::{common_header, QualityItem, CONTENT_LANGUAGE};
+
+common_header! {
     /// `Content-Language` header, defined
     /// in [RFC 7231 §3.1.3.2](https://datatracker.ietf.org/doc/html/rfc7231#section-3.1.3.2)
     ///
@@ -11,7 +12,7 @@ crate::http::header::common_header! {
     /// representation.
     ///
     /// # ABNF
-    /// ```text
+    /// ```plain
     /// Content-Language = 1#language-tag
     /// ```
     ///
diff --git a/src/http/header/content_range.rs b/src/http/header/content_range.rs
index 9966a2582..90b3f7fe2 100644
--- a/src/http/header/content_range.rs
+++ b/src/http/header/content_range.rs
@@ -75,7 +75,7 @@ crate::http::header::common_header! {
 /// in [RFC 7233 §4.2](https://datatracker.ietf.org/doc/html/rfc7233#section-4.2)
 ///
 /// # ABNF
-/// ```text
+/// ```plain
 /// Content-Range       = byte-content-range
 ///                     / other-content-range
 ///
@@ -91,7 +91,7 @@ crate::http::header::common_header! {
 /// other-content-range = other-range-unit SP other-range-resp
 /// other-range-resp    = *CHAR
 /// ```
-#[derive(PartialEq, Clone, Debug)]
+#[derive(Debug, Clone, PartialEq, Eq)]
 pub enum ContentRangeSpec {
     /// Byte range
     Bytes {
diff --git a/src/http/header/content_type.rs b/src/http/header/content_type.rs
index 624a51711..1fc75d0e2 100644
--- a/src/http/header/content_type.rs
+++ b/src/http/header/content_type.rs
@@ -18,7 +18,7 @@ crate::http::header::common_header! {
     /// this is an issue, it's possible to implement `Header` on a custom struct.
     ///
     /// # ABNF
-    /// ```text
+    /// ```plain
     /// Content-Type = media-type
     /// ```
     ///
@@ -110,5 +110,3 @@ impl ContentType {
         ContentType(mime::APPLICATION_OCTET_STREAM)
     }
 }
-
-impl Eq for ContentType {}
diff --git a/src/http/header/date.rs b/src/http/header/date.rs
index 08c9b7ed1..4063deab1 100644
--- a/src/http/header/date.rs
+++ b/src/http/header/date.rs
@@ -9,7 +9,7 @@ crate::http::header::common_header! {
     /// message was originated.
     ///
     /// # ABNF
-    /// ```text
+    /// ```plain
     /// Date = HTTP-date
     /// ```
     ///
diff --git a/src/http/header/entity.rs b/src/http/header/entity.rs
index ff8e17287..50b40b7b2 100644
--- a/src/http/header/entity.rs
+++ b/src/http/header/entity.rs
@@ -26,7 +26,7 @@ fn check_slice_validity(slice: &str) -> bool {
 /// `W/"xyzzy"`.
 ///
 /// # ABNF
-/// ```text
+/// ```plain
 /// entity-tag = [ weak ] opaque-tag
 /// weak       = %x57.2F ; "W/", case-sensitive
 /// opaque-tag = DQUOTE *etagc DQUOTE
diff --git a/src/http/header/etag.rs b/src/http/header/etag.rs
index 11206407d..4724c917e 100644
--- a/src/http/header/etag.rs
+++ b/src/http/header/etag.rs
@@ -15,7 +15,7 @@ crate::http::header::common_header! {
     /// prefixed by a weakness indicator.
     ///
     /// # ABNF
-    /// ```text
+    /// ```plain
     /// ETag       = entity-tag
     /// ```
     ///
diff --git a/src/http/header/expires.rs b/src/http/header/expires.rs
index 7ff78be85..5b6c65c53 100644
--- a/src/http/header/expires.rs
+++ b/src/http/header/expires.rs
@@ -12,7 +12,7 @@ crate::http::header::common_header! {
     /// time.
     ///
     /// # ABNF
-    /// ```text
+    /// ```plain
     /// Expires = HTTP-date
     /// ```
     ///
diff --git a/src/http/header/if_match.rs b/src/http/header/if_match.rs
index ac06fa876..a565b9125 100644
--- a/src/http/header/if_match.rs
+++ b/src/http/header/if_match.rs
@@ -1,6 +1,6 @@
-use super::{EntityTag, IF_MATCH};
+use super::{common_header, EntityTag, IF_MATCH};
 
-crate::http::header::common_header! {
+common_header! {
     /// `If-Match` header, defined
     /// in [RFC 7232 §3.1](https://datatracker.ietf.org/doc/html/rfc7232#section-3.1)
     ///
@@ -17,7 +17,7 @@ crate::http::header::common_header! {
     /// there have been any changes to the representation data.
     ///
     /// # ABNF
-    /// ```text
+    /// ```plain
     /// If-Match = "*" / 1#entity-tag
     /// ```
     ///
diff --git a/src/http/header/if_modified_since.rs b/src/http/header/if_modified_since.rs
index 0d23be188..14d6c3553 100644
--- a/src/http/header/if_modified_since.rs
+++ b/src/http/header/if_modified_since.rs
@@ -11,7 +11,7 @@ crate::http::header::common_header! {
     /// data has not changed.
     ///
     /// # ABNF
-    /// ```text
+    /// ```plain
     /// If-Unmodified-Since = HTTP-date
     /// ```
     ///
diff --git a/src/http/header/if_none_match.rs b/src/http/header/if_none_match.rs
index 80f87ed7b..fb1895fc8 100644
--- a/src/http/header/if_none_match.rs
+++ b/src/http/header/if_none_match.rs
@@ -16,7 +16,7 @@ crate::http::header::common_header! {
     /// the representation data.
     ///
     /// # ABNF
-    /// ```text
+    /// ```plain
     /// If-None-Match = "*" / 1#entity-tag
     /// ```
     ///
diff --git a/src/http/header/if_range.rs b/src/http/header/if_range.rs
index 9a51ab3a8..5af9255f6 100644
--- a/src/http/header/if_range.rs
+++ b/src/http/header/if_range.rs
@@ -25,7 +25,7 @@ use crate::HttpMessage;
 /// in Range; otherwise, send me the entire representation.
 ///
 /// # ABNF
-/// ```text
+/// ```plain
 /// If-Range = entity-tag / HTTP-date
 /// ```
 ///
@@ -107,10 +107,11 @@ impl IntoHeaderValue for IfRange {
 }
 
 #[cfg(test)]
-mod test_if_range {
+mod test_parse_and_format {
+    use std::str;
+
     use super::IfRange as HeaderField;
     use crate::http::header::*;
-    use std::str;
 
     crate::http::header::common_header_test!(test1, vec![b"Sat, 29 Oct 1994 19:43:31 GMT"]);
     crate::http::header::common_header_test!(test2, vec![b"\"abc\""]);
diff --git a/src/http/header/if_unmodified_since.rs b/src/http/header/if_unmodified_since.rs
index d0498682b..0df6d7ba0 100644
--- a/src/http/header/if_unmodified_since.rs
+++ b/src/http/header/if_unmodified_since.rs
@@ -11,7 +11,7 @@ crate::http::header::common_header! {
     /// the user agent does not have an entity-tag for the representation.
     ///
     /// # ABNF
-    /// ```text
+    /// ```plain
     /// If-Unmodified-Since = HTTP-date
     /// ```
     ///
diff --git a/src/http/header/last_modified.rs b/src/http/header/last_modified.rs
index ce5c829c2..e15443ed1 100644
--- a/src/http/header/last_modified.rs
+++ b/src/http/header/last_modified.rs
@@ -10,7 +10,7 @@ crate::http::header::common_header! {
     /// conclusion of handling the request.
     ///
     /// # ABNF
-    /// ```text
+    /// ```plain
     /// Expires = HTTP-date
     /// ```
     ///
diff --git a/src/http/header/macros.rs b/src/http/header/macros.rs
index 7fed7f286..d91d1d282 100644
--- a/src/http/header/macros.rs
+++ b/src/http/header/macros.rs
@@ -1,25 +1,3 @@
-// TODO: replace with derive_more impl
-macro_rules! common_header_deref {
-    ($from:ty => $to:ty) => {
-        impl ::core::ops::Deref for $from {
-            type Target = $to;
-
-            #[inline]
-            fn deref(&self) -> &Self::Target {
-                &self.0
-            }
-        }
-
-        impl ::core::ops::DerefMut for $from {
-            #[inline]
-            fn deref_mut(&mut self) -> &mut Self::Target {
-                &mut self.0
-            }
-        }
-    };
-}
-
-/// Sets up a test module with some useful imports for use with [`common_header_test!`].
 macro_rules! common_header_test_module {
     ($id:ident, $tm:ident{$($tf:item)*}) => {
         #[cfg(test)]
@@ -87,10 +65,6 @@ macro_rules! common_header_test {
             let val = HeaderField::parse(&req);
             let exp: Option<HeaderField> = $exp;
 
-            println!("req: {:?}", &req);
-            println!("val: {:?}", &val);
-            println!("exp: {:?}", &exp);
-
             // test parsing
             assert_eq!(val.ok(), exp);
 
@@ -114,17 +88,17 @@ macro_rules! common_header_test {
 
 macro_rules! common_header {
     // TODO: these docs are wrong, there's no $n or $nn
-    // $a:meta: Attributes associated with the header item (usually docs)
+    // $attrs:meta: Attributes associated with the header item (usually docs)
     // $id:ident: Identifier of the header
     // $n:expr: Lowercase name of the header
     // $nn:expr: Nice name of the header
 
     // List header, zero or more items
-    ($(#[$a:meta])*($id:ident, $name:expr) => ($item:ty)*) => {
-        $(#[$a])*
-        #[derive(Clone, Debug, PartialEq)]
+    ($(#[$attrs:meta])*($id:ident, $name:expr) => ($item:ty)*) => {
+        $(#[$attrs])*
+        #[derive(Debug, Clone, PartialEq, Eq, ::derive_more::Deref, ::derive_more::DerefMut)]
         pub struct $id(pub Vec<$item>);
-        crate::http::header::common_header_deref!($id => Vec<$item>);
+
         impl $crate::http::header::Header for $id {
             #[inline]
             fn name() -> $crate::http::header::HeaderName {
@@ -158,13 +132,11 @@ macro_rules! common_header {
     };
 
     // List header, one or more items
-    ($(#[$a:meta])*($id:ident, $name:expr) => ($item:ty)+) => {
-        $(#[$a])*
-        #[derive(Clone, Debug, PartialEq)]
+    ($(#[$attrs:meta])*($id:ident, $name:expr) => ($item:ty)+) => {
+        $(#[$attrs])*
+        #[derive(Debug, Clone, PartialEq, Eq, ::derive_more::Deref, ::derive_more::DerefMut)]
         pub struct $id(pub Vec<$item>);
 
-        crate::http::header::common_header_deref!($id => Vec<$item>);
-
         impl $crate::http::header::Header for $id {
             #[inline]
             fn name() -> $crate::http::header::HeaderName {
@@ -197,13 +169,11 @@ macro_rules! common_header {
     };
 
     // Single value header
-    ($(#[$a:meta])*($id:ident, $name:expr) => [$value:ty]) => {
-        $(#[$a])*
-        #[derive(Clone, Debug, PartialEq)]
+    ($(#[$attrs:meta])*($id:ident, $name:expr) => [$value:ty]) => {
+        $(#[$attrs])*
+        #[derive(Debug, Clone, PartialEq, Eq, ::derive_more::Deref, ::derive_more::DerefMut)]
         pub struct $id(pub $value);
 
-        crate::http::header::common_header_deref!($id => $value);
-
         impl $crate::http::header::Header for $id {
             #[inline]
             fn name() -> $crate::http::header::HeaderName {
@@ -234,8 +204,8 @@ macro_rules! common_header {
     };
 
     // List header, one or more items with "*" option
-    ($(#[$a:meta])*($id:ident, $name:expr) => {Any / ($item:ty)+}) => {
-        $(#[$a])*
+    ($(#[$attrs:meta])*($id:ident, $name:expr) => {Any / ($item:ty)+}) => {
+        $(#[$attrs])*
         #[derive(Clone, Debug, PartialEq)]
         pub enum $id {
             /// Any value is a match
@@ -291,32 +261,32 @@ macro_rules! common_header {
     };
 
     // optional test module
-    ($(#[$a:meta])*($id:ident, $name:expr) => ($item:ty)* $tm:ident{$($tf:item)*}) => {
+    ($(#[$attrs:meta])*($id:ident, $name:expr) => ($item:ty)* $tm:ident{$($tf:item)*}) => {
         crate::http::header::common_header! {
-            $(#[$a])*
+            $(#[$attrs])*
             ($id, $name) => ($item)*
         }
 
         crate::http::header::common_header_test_module! { $id, $tm { $($tf)* }}
     };
-    ($(#[$a:meta])*($id:ident, $n:expr) => ($item:ty)+ $tm:ident{$($tf:item)*}) => {
+    ($(#[$attrs:meta])*($id:ident, $n:expr) => ($item:ty)+ $tm:ident{$($tf:item)*}) => {
         crate::http::header::common_header! {
-            $(#[$a])*
+            $(#[$attrs])*
             ($id, $n) => ($item)+
         }
 
         crate::http::header::common_header_test_module! { $id, $tm { $($tf)* }}
     };
-    ($(#[$a:meta])*($id:ident, $name:expr) => [$item:ty] $tm:ident{$($tf:item)*}) => {
+    ($(#[$attrs:meta])*($id:ident, $name:expr) => [$item:ty] $tm:ident{$($tf:item)*}) => {
         crate::http::header::common_header! {
-            $(#[$a])* ($id, $name) => [$item]
+            $(#[$attrs])* ($id, $name) => [$item]
         }
 
         crate::http::header::common_header_test_module! { $id, $tm { $($tf)* }}
     };
-    ($(#[$a:meta])*($id:ident, $name:expr) => {Any / ($item:ty)+} $tm:ident{$($tf:item)*}) => {
+    ($(#[$attrs:meta])*($id:ident, $name:expr) => {Any / ($item:ty)+} $tm:ident{$($tf:item)*}) => {
         crate::http::header::common_header! {
-            $(#[$a])*
+            $(#[$attrs])*
             ($id, $name) => {Any / ($item)+}
         }
 
@@ -324,7 +294,7 @@ macro_rules! common_header {
     };
 }
 
-pub(crate) use {common_header, common_header_deref, common_header_test_module};
+pub(crate) use {common_header, common_header_test_module};
 
 #[cfg(test)]
 pub(crate) use common_header_test;
diff --git a/src/http/header/mod.rs b/src/http/header/mod.rs
index 45d5b8d1a..750f0e5b9 100644
--- a/src/http/header/mod.rs
+++ b/src/http/header/mod.rs
@@ -44,7 +44,7 @@ mod preference;
 
 #[cfg(test)]
 pub(crate) use macros::common_header_test;
-pub(crate) use macros::{common_header, common_header_deref, common_header_test_module};
+pub(crate) use macros::{common_header, common_header_test_module};
 
 pub use self::accept_charset::AcceptCharset;
 //pub use self::accept_encoding::AcceptEncoding;
diff --git a/src/http/header/range.rs b/src/http/header/range.rs
index f57bac912..11006ffff 100644
--- a/src/http/header/range.rs
+++ b/src/http/header/range.rs
@@ -1,8 +1,11 @@
-use std::fmt::{self, Display};
-use std::str::FromStr;
+// TODO: reinstate module
 
-use super::parsing::from_one_raw_str;
-use super::{Header, Raw};
+use std::{
+    fmt::{self, Display},
+    str::FromStr,
+};
+
+use super::{parsing::from_one_raw_str, Header, Raw};
 
 /// `Range` header, defined
 /// in [RFC 7233 §3.1](https://datatracker.ietf.org/doc/html/rfc7233#section-3.1)
@@ -12,7 +15,7 @@ use super::{Header, Raw};
 /// representation data.
 ///
 /// # ABNF
-/// ```text
+/// ```plain
 /// Range =	byte-ranges-specifier / other-ranges-specifier
 /// other-ranges-specifier = other-range-unit "=" other-range-set
 /// other-range-set = 1*VCHAR

From deece8d519512a83a98c7b8b1cdcd664fc0ee03a Mon Sep 17 00:00:00 2001
From: Rob Ede <robjtede@icloud.com>
Date: Thu, 2 Dec 2021 17:04:40 +0000
Subject: [PATCH 3/3] re-instate accept-encoding typed header (#2482)

---
 CHANGES.md                                   |   3 +
 actix-http/src/header/shared/quality_item.rs |   2 +-
 actix-http/src/header/utils.rs               |   7 +
 scripts/ci-test                              |   2 +
 src/http/header/accept.rs                    |   5 +-
 src/http/header/accept_encoding.rs           |  23 +-
 src/http/header/accept_language.rs           |   1 +
 src/http/header/cache_control.rs             | 290 +++++++------------
 src/http/header/encoding.rs                  |  13 +-
 src/http/header/macros.rs                    |  51 +++-
 src/http/header/mod.rs                       |   8 +-
 11 files changed, 190 insertions(+), 215 deletions(-)

diff --git a/CHANGES.md b/CHANGES.md
index 36a56b828..c754d4dd6 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -3,6 +3,7 @@
 ## Unreleased - 2021-xx-xx
 ### Added
 * Methods on `AcceptLanguage`: `ranked` and `preference`. [#2480]
+* `AcceptEncoding` typed header. [#2482]
 
 ### Changed
 * Rename `Accept::{mime_precedence => ranked}`. [#2480]
@@ -10,8 +11,10 @@
 
 ### Fixed
 * Accept wildcard `*` items in `AcceptLanguage`. [#2480]
+* Typed headers containing lists that require one or more items now enforce this minimum. [#2482]
 
 [#2480]: https://github.com/actix/actix-web/pull/2480
+[#2482]: https://github.com/actix/actix-web/pull/2482
 
 
 ## 4.0.0-beta.13 - 2021-11-30
diff --git a/actix-http/src/header/shared/quality_item.rs b/actix-http/src/header/shared/quality_item.rs
index 9b170f01a..a109b44ea 100644
--- a/actix-http/src/header/shared/quality_item.rs
+++ b/actix-http/src/header/shared/quality_item.rs
@@ -27,7 +27,7 @@ const MAX_FLOAT_QUALITY: f32 = 1.0;
 ///
 /// [RFC 7231 §5.3.1](https://datatracker.ietf.org/doc/html/rfc7231#section-5.3.1) gives more
 /// information on quality values in HTTP header fields.
-#[derive(Debug, Copy, Clone, PartialEq, Eq, PartialOrd, Ord)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
 pub struct Quality(u16);
 
 impl Quality {
diff --git a/actix-http/src/header/utils.rs b/actix-http/src/header/utils.rs
index 2168202b9..a23f5b751 100644
--- a/actix-http/src/header/utils.rs
+++ b/actix-http/src/header/utils.rs
@@ -83,6 +83,13 @@ mod tests {
         let res: Vec<usize> = from_comma_delimited(headers.iter()).unwrap();
         assert_eq!(res, vec![0; 0]);
 
+        let headers = vec![
+            HeaderValue::from_static("1, 2"),
+            HeaderValue::from_static("3,4"),
+        ];
+        let res: Vec<usize> = from_comma_delimited(headers.iter()).unwrap();
+        assert_eq!(res, vec![1, 2, 3, 4]);
+
         let headers = vec![
             HeaderValue::from_static(""),
             HeaderValue::from_static(","),
diff --git a/scripts/ci-test b/scripts/ci-test
index 096eb7600..98e13927d 100755
--- a/scripts/ci-test
+++ b/scripts/ci-test
@@ -14,3 +14,5 @@ cargo test --lib --tests -p=actix-test --all-features
 cargo test --lib --tests -p=actix-files
 cargo test --lib --tests -p=actix-multipart --all-features
 cargo test --lib --tests -p=actix-web-actors --all-features
+
+cargo test --workspace --doc
diff --git a/src/http/header/accept.rs b/src/http/header/accept.rs
index a0c98547d..fe291c011 100644
--- a/src/http/header/accept.rs
+++ b/src/http/header/accept.rs
@@ -118,8 +118,9 @@ crate::http::header::common_header! {
 
         #[test]
         fn test_fuzzing1() {
-            use actix_http::test::TestRequest;
-            let req = TestRequest::default().insert_header((crate::http::header::ACCEPT, "chunk#;e")).finish();
+            let req = test::TestRequest::default()
+                .insert_header((header::ACCEPT, "chunk#;e"))
+                .finish();
             let header = Accept::parse(&req);
             assert!(header.is_ok());
         }
diff --git a/src/http/header/accept_encoding.rs b/src/http/header/accept_encoding.rs
index 0440153ae..85cd0a4f7 100644
--- a/src/http/header/accept_encoding.rs
+++ b/src/http/header/accept_encoding.rs
@@ -1,8 +1,9 @@
-// TODO: reinstate module
+use actix_http::header::QualityItem;
 
-use header::{Encoding, QualityItem};
+use super::{common_header, Encoding};
+use crate::http::header;
 
-header! {
+common_header! {
     /// `Accept-Encoding` header, defined
     /// in [RFC 7231](https://datatracker.ietf.org/doc/html/rfc7231#section-5.3.4)
     ///
@@ -30,7 +31,7 @@ header! {
     /// use actix_web::HttpResponse;
     /// use actix_web::http::header::{AcceptEncoding, Encoding, qitem};
     ///
-    /// let mut builder = HttpResponse::new();
+    /// let mut builder = HttpResponse::Ok();
     /// builder.insert_header(
     ///     AcceptEncoding(vec![qitem(Encoding::Chunked)])
     /// );
@@ -39,7 +40,7 @@ header! {
     /// use actix_web::HttpResponse;
     /// use actix_web::http::header::{AcceptEncoding, Encoding, qitem};
     ///
-    /// let mut builder = HttpResponse::new();
+    /// let mut builder = HttpResponse::Ok();
     /// builder.insert_header(
     ///     AcceptEncoding(vec![
     ///         qitem(Encoding::Chunked),
@@ -52,7 +53,7 @@ header! {
     /// use actix_web::HttpResponse;
     /// use actix_web::http::header::{AcceptEncoding, Encoding, QualityItem, q, qitem};
     ///
-    /// let mut builder = HttpResponse::new();
+    /// let mut builder = HttpResponse::Ok();
     /// builder.insert_header(
     ///     AcceptEncoding(vec![
     ///         qitem(Encoding::Chunked),
@@ -65,14 +66,14 @@ header! {
 
     test_parse_and_format {
         // From the RFC
-        crate::http::header::common_header_test!(test1, vec![b"compress, gzip"]);
-        crate::http::header::common_header_test!(test2, vec![b""], Some(AcceptEncoding(vec![])));
-        crate::http::header::common_header_test!(test3, vec![b"*"]);
+        common_header_test!(test1, vec![b"compress, gzip"]);
+        common_header_test!(test2, vec![b""], Some(AcceptEncoding(vec![])));
+        common_header_test!(test3, vec![b"*"]);
 
         // Note: Removed quality 1 from gzip
-        crate::http::header::common_header_test!(test4, vec![b"compress;q=0.5, gzip"]);
+        common_header_test!(test4, vec![b"compress;q=0.5, gzip"]);
 
         // Note: Removed quality 1 from gzip
-        crate::http::header::common_header_test!(test5, vec![b"gzip, identity; q=0.5, *;q=0"]);
+        common_header_test!(test5, vec![b"gzip, identity; q=0.5, *;q=0"]);
     }
 }
diff --git a/src/http/header/accept_language.rs b/src/http/header/accept_language.rs
index fb1637eb1..229f95ef1 100644
--- a/src/http/header/accept_language.rs
+++ b/src/http/header/accept_language.rs
@@ -67,6 +67,7 @@ common_header! {
             vec![b"da, en-gb;q=0.8, en;q=0.7"]
         );
 
+
         common_header_test!(
             not_ordered_by_weight,
             vec![b"en-US, en; q=0.5, fr"],
diff --git a/src/http/header/cache_control.rs b/src/http/header/cache_control.rs
index 27cf30ce4..490d36558 100644
--- a/src/http/header/cache_control.rs
+++ b/src/http/header/cache_control.rs
@@ -1,92 +1,97 @@
-use std::fmt::{self, Write};
-use std::str::FromStr;
-
-use derive_more::{Deref, DerefMut};
-
-use super::{fmt_comma_delimited, from_comma_delimited, Header, IntoHeaderValue, Writer};
+use std::{fmt, str};
 
+use super::common_header;
 use crate::http::header;
 
-/// `Cache-Control` header, defined
-/// in [RFC 7234 §5.2](https://datatracker.ietf.org/doc/html/rfc7234#section-5.2).
-///
-/// The `Cache-Control` header field is used to specify directives for
-/// caches along the request/response chain.  Such cache directives are
-/// unidirectional in that the presence of a directive in a request does
-/// not imply that the same directive is to be given in the response.
-///
-/// # ABNF
-/// ```plain
-/// Cache-Control   = 1#cache-directive
-/// cache-directive = token [ "=" ( token / quoted-string ) ]
-/// ```
-///
-/// # Example Values
-///
-/// * `no-cache`
-/// * `private, community="UCI"`
-/// * `max-age=30`
-///
-/// # Examples
-/// ```
-/// use actix_web::HttpResponse;
-/// use actix_web::http::header::{CacheControl, CacheDirective};
-///
-/// let mut builder = HttpResponse::Ok();
-/// builder.insert_header(CacheControl(vec![CacheDirective::MaxAge(86400u32)]));
-/// ```
-///
-/// ```
-/// use actix_web::HttpResponse;
-/// use actix_web::http::header::{CacheControl, CacheDirective};
-///
-/// let mut builder = HttpResponse::Ok();
-/// builder.insert_header(CacheControl(vec![
-///     CacheDirective::NoCache,
-///     CacheDirective::Private,
-///     CacheDirective::MaxAge(360u32),
-///     CacheDirective::Extension("foo".to_owned(), Some("bar".to_owned())),
-/// ]));
-/// ```
-#[derive(Debug, Clone, PartialEq, Eq, Deref, DerefMut)]
-pub struct CacheControl(pub Vec<CacheDirective>);
+common_header! {
+    /// `Cache-Control` header, defined
+    /// in [RFC 7234 §5.2](https://datatracker.ietf.org/doc/html/rfc7234#section-5.2).
+    ///
+    /// The `Cache-Control` header field is used to specify directives for
+    /// caches along the request/response chain.  Such cache directives are
+    /// unidirectional in that the presence of a directive in a request does
+    /// not imply that the same directive is to be given in the response.
+    ///
+    /// # ABNF
+    /// ```text
+    /// Cache-Control   = 1#cache-directive
+    /// cache-directive = token [ "=" ( token / quoted-string ) ]
+    /// ```
+    ///
+    /// # Example Values
+    /// * `no-cache`
+    /// * `private, community="UCI"`
+    /// * `max-age=30`
+    ///
+    /// # Examples
+    /// ```
+    /// use actix_web::HttpResponse;
+    /// use actix_web::http::header::{CacheControl, CacheDirective};
+    ///
+    /// let mut builder = HttpResponse::Ok();
+    /// builder.insert_header(CacheControl(vec![CacheDirective::MaxAge(86400u32)]));
+    /// ```
+    ///
+    /// ```
+    /// use actix_web::HttpResponse;
+    /// use actix_web::http::header::{CacheControl, CacheDirective};
+    ///
+    /// let mut builder = HttpResponse::Ok();
+    /// builder.insert_header(CacheControl(vec![
+    ///     CacheDirective::NoCache,
+    ///     CacheDirective::Private,
+    ///     CacheDirective::MaxAge(360u32),
+    ///     CacheDirective::Extension("foo".to_owned(), Some("bar".to_owned())),
+    /// ]));
+    /// ```
+    (CacheControl, header::CACHE_CONTROL) => (CacheDirective)+
 
-// TODO: this could just be the crate::http::header::common_header! macro
-impl Header for CacheControl {
-    fn name() -> header::HeaderName {
-        header::CACHE_CONTROL
-    }
+    test_parse_and_format {
+        common_header_test!(no_headers, vec![b""; 0], None);
+        common_header_test!(empty_header, vec![b""; 1], None);
+        common_header_test!(bad_syntax, vec![b"foo="], None);
 
-    #[inline]
-    fn parse<T>(msg: &T) -> Result<Self, crate::error::ParseError>
-    where
-        T: crate::HttpMessage,
-    {
-        let directives = from_comma_delimited(msg.headers().get_all(&Self::name()))?;
-        if !directives.is_empty() {
-            Ok(CacheControl(directives))
-        } else {
-            Err(crate::error::ParseError::Header)
+        common_header_test!(
+            multiple_headers,
+            vec![&b"no-cache"[..], &b"private"[..]],
+            Some(CacheControl(vec![
+                CacheDirective::NoCache,
+                CacheDirective::Private,
+            ]))
+        );
+
+        common_header_test!(
+            argument,
+            vec![b"max-age=100, private"],
+            Some(CacheControl(vec![
+                CacheDirective::MaxAge(100),
+                CacheDirective::Private,
+            ]))
+        );
+
+        common_header_test!(
+            extension,
+            vec![b"foo, bar=baz"],
+            Some(CacheControl(vec![
+                CacheDirective::Extension("foo".to_owned(), None),
+                CacheDirective::Extension("bar".to_owned(), Some("baz".to_owned())),
+            ]))
+        );
+
+        #[test]
+        fn parse_quote_form() {
+            let req = test::TestRequest::default()
+                .insert_header((header::CACHE_CONTROL, "max-age=\"200\""))
+                .finish();
+
+            assert_eq!(
+                Header::parse(&req).ok(),
+                Some(CacheControl(vec![CacheDirective::MaxAge(200)]))
+            )
         }
     }
 }
 
-impl fmt::Display for CacheControl {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        fmt_comma_delimited(f, &self.0[..])
-    }
-}
-
-impl IntoHeaderValue for CacheControl {
-    type Error = header::InvalidHeaderValue;
-
-    fn try_into_value(self) -> Result<header::HeaderValue, Self::Error> {
-        let mut writer = Writer::new();
-        let _ = write!(&mut writer, "{}", self);
-        header::HeaderValue::from_maybe_shared(writer.take())
-    }
-}
-
 /// `CacheControl` contains a list of these directives.
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub enum CacheDirective {
@@ -126,38 +131,40 @@ pub enum CacheDirective {
 impl fmt::Display for CacheDirective {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         use self::CacheDirective::*;
-        fmt::Display::fmt(
-            match *self {
-                NoCache => "no-cache",
-                NoStore => "no-store",
-                NoTransform => "no-transform",
-                OnlyIfCached => "only-if-cached",
 
-                MaxAge(secs) => return write!(f, "max-age={}", secs),
-                MaxStale(secs) => return write!(f, "max-stale={}", secs),
-                MinFresh(secs) => return write!(f, "min-fresh={}", secs),
+        let dir_str = match self {
+            NoCache => "no-cache",
+            NoStore => "no-store",
+            NoTransform => "no-transform",
+            OnlyIfCached => "only-if-cached",
 
-                MustRevalidate => "must-revalidate",
-                Public => "public",
-                Private => "private",
-                ProxyRevalidate => "proxy-revalidate",
-                SMaxAge(secs) => return write!(f, "s-maxage={}", secs),
+            MaxAge(secs) => return write!(f, "max-age={}", secs),
+            MaxStale(secs) => return write!(f, "max-stale={}", secs),
+            MinFresh(secs) => return write!(f, "min-fresh={}", secs),
 
-                Extension(ref name, None) => &name[..],
-                Extension(ref name, Some(ref arg)) => {
-                    return write!(f, "{}={}", name, arg);
-                }
-            },
-            f,
-        )
+            MustRevalidate => "must-revalidate",
+            Public => "public",
+            Private => "private",
+            ProxyRevalidate => "proxy-revalidate",
+            SMaxAge(secs) => return write!(f, "s-maxage={}", secs),
+
+            Extension(name, None) => name.as_str(),
+            Extension(name, Some(arg)) => return write!(f, "{}={}", name, arg),
+        };
+
+        f.write_str(dir_str)
     }
 }
 
-impl FromStr for CacheDirective {
-    type Err = Option<<u32 as FromStr>::Err>;
-    fn from_str(s: &str) -> Result<CacheDirective, Option<<u32 as FromStr>::Err>> {
+impl str::FromStr for CacheDirective {
+    type Err = Option<<u32 as str::FromStr>::Err>;
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
         use self::CacheDirective::*;
+
         match s {
+            "" => Err(None),
+
             "no-cache" => Ok(NoCache),
             "no-store" => Ok(NoStore),
             "no-transform" => Ok(NoTransform),
@@ -166,7 +173,7 @@ impl FromStr for CacheDirective {
             "public" => Ok(Public),
             "private" => Ok(Private),
             "proxy-revalidate" => Ok(ProxyRevalidate),
-            "" => Err(None),
+
             _ => match s.find('=') {
                 Some(idx) if idx + 1 < s.len() => {
                     match (&s[..idx], (&s[idx + 1..]).trim_matches('"')) {
@@ -183,76 +190,3 @@ impl FromStr for CacheDirective {
         }
     }
 }
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-    use crate::http::header::Header;
-    use actix_http::test::TestRequest;
-
-    #[test]
-    fn test_parse_multiple_headers() {
-        let req = TestRequest::default()
-            .insert_header((header::CACHE_CONTROL, "no-cache, private"))
-            .finish();
-        let cache = Header::parse(&req);
-        assert_eq!(
-            cache.ok(),
-            Some(CacheControl(vec![
-                CacheDirective::NoCache,
-                CacheDirective::Private,
-            ]))
-        )
-    }
-
-    #[test]
-    fn test_parse_argument() {
-        let req = TestRequest::default()
-            .insert_header((header::CACHE_CONTROL, "max-age=100, private"))
-            .finish();
-        let cache = Header::parse(&req);
-        assert_eq!(
-            cache.ok(),
-            Some(CacheControl(vec![
-                CacheDirective::MaxAge(100),
-                CacheDirective::Private,
-            ]))
-        )
-    }
-
-    #[test]
-    fn test_parse_quote_form() {
-        let req = TestRequest::default()
-            .insert_header((header::CACHE_CONTROL, "max-age=\"200\""))
-            .finish();
-        let cache = Header::parse(&req);
-        assert_eq!(
-            cache.ok(),
-            Some(CacheControl(vec![CacheDirective::MaxAge(200)]))
-        )
-    }
-
-    #[test]
-    fn test_parse_extension() {
-        let req = TestRequest::default()
-            .insert_header((header::CACHE_CONTROL, "foo, bar=baz"))
-            .finish();
-        let cache = Header::parse(&req);
-        assert_eq!(
-            cache.ok(),
-            Some(CacheControl(vec![
-                CacheDirective::Extension("foo".to_owned(), None),
-                CacheDirective::Extension("bar".to_owned(), Some("baz".to_owned())),
-            ]))
-        )
-    }
-
-    #[test]
-    fn test_parse_bad_syntax() {
-        let req = TestRequest::default()
-            .insert_header((header::CACHE_CONTROL, "foo="))
-            .finish();
-        let cache: Result<CacheControl, _> = Header::parse(&req);
-        assert_eq!(cache.ok(), None)
-    }
-}
diff --git a/src/http/header/encoding.rs b/src/http/header/encoding.rs
index ce31c100f..a61edda67 100644
--- a/src/http/header/encoding.rs
+++ b/src/http/header/encoding.rs
@@ -4,26 +4,33 @@ pub use self::Encoding::{
     Brotli, Chunked, Compress, Deflate, EncodingExt, Gzip, Identity, Trailers, Zstd,
 };
 
-/// A value to represent an encoding used in `Transfer-Encoding`
-/// or `Accept-Encoding` header.
-#[derive(Clone, PartialEq, Debug)]
+/// A value to represent an encoding used in `Transfer-Encoding` or `Accept-Encoding` header.
+#[derive(Debug, Clone, PartialEq, Eq)]
 pub enum Encoding {
     /// The `chunked` encoding.
     Chunked,
+
     /// The `br` encoding.
     Brotli,
+
     /// The `gzip` encoding.
     Gzip,
+
     /// The `deflate` encoding.
     Deflate,
+
     /// The `compress` encoding.
     Compress,
+
     /// The `identity` encoding.
     Identity,
+
     /// The `trailers` encoding.
     Trailers,
+
     /// The `zstd` encoding.
     Zstd,
+
     /// Some other encoding that is less common, can be any String.
     EncodingExt(String),
 }
diff --git a/src/http/header/macros.rs b/src/http/header/macros.rs
index d91d1d282..3f530658c 100644
--- a/src/http/header/macros.rs
+++ b/src/http/header/macros.rs
@@ -4,11 +4,14 @@ macro_rules! common_header_test_module {
         mod $tm {
             #![allow(unused_imports)]
 
-            use std::str;
-            use actix_http::http::Method;
-            use mime::*;
-            use $crate::http::header::*;
+            use ::core::str;
+
+            use ::actix_http::{http::Method, test};
+            use ::mime::*;
+
+            use $crate::http::header::{self, *};
             use super::{$id as HeaderField, *};
+
             $($tf)*
         }
     }
@@ -19,22 +22,22 @@ macro_rules! common_header_test {
     ($id:ident, $raw:expr) => {
         #[test]
         fn $id() {
-            use actix_http::test;
+            use ::actix_http::test;
 
             let raw = $raw;
-            let a: Vec<Vec<u8>> = raw.iter().map(|x| x.to_vec()).collect();
+            let headers = raw.iter().map(|x| x.to_vec()).collect::<Vec<_>>();
 
             let mut req = test::TestRequest::default();
 
-            for item in a {
-                req = req.insert_header((HeaderField::name(), item)).take();
+            for item in headers {
+                req = req.append_header((HeaderField::name(), item)).take();
             }
 
             let req = req.finish();
             let value = HeaderField::parse(&req);
 
             let result = format!("{}", value.unwrap());
-            let expected = String::from_utf8(raw[0].to_vec()).unwrap();
+            let expected = ::std::string::String::from_utf8(raw[0].to_vec()).unwrap();
 
             let result_cmp: Vec<String> = result
                 .to_ascii_lowercase()
@@ -56,14 +59,17 @@ macro_rules! common_header_test {
         fn $id() {
             use actix_http::test;
 
-            let a: Vec<Vec<u8>> = $raw.iter().map(|x| x.to_vec()).collect();
+            let headers = $raw.iter().map(|x| x.to_vec()).collect::<Vec<_>>();
             let mut req = test::TestRequest::default();
-            for item in a {
-                req.insert_header((HeaderField::name(), item));
+
+            for item in headers {
+                req.append_header((HeaderField::name(), item));
             }
+
             let req = req.finish();
             let val = HeaderField::parse(&req);
-            let exp: Option<HeaderField> = $exp;
+
+            let exp: ::core::option::Option<HeaderField> = $exp;
 
             // test parsing
             assert_eq!(val.ok(), exp);
@@ -122,6 +128,7 @@ macro_rules! common_header {
         impl $crate::http::header::IntoHeaderValue for $id {
             type Error = $crate::http::header::InvalidHeaderValue;
 
+            #[inline]
             fn try_into_value(self) -> Result<$crate::http::header::HeaderValue, Self::Error> {
                 use ::core::fmt::Write;
                 let mut writer = $crate::http::header::Writer::new();
@@ -142,10 +149,19 @@ macro_rules! common_header {
             fn name() -> $crate::http::header::HeaderName {
                 $name
             }
+
             #[inline]
-            fn parse<M: $crate::HttpMessage>(msg: &M) -> Result<Self, $crate::error::ParseError> {
-                $crate::http::header::from_comma_delimited(
-                    msg.headers().get_all(Self::name())).map($id)
+            fn parse<M: $crate::HttpMessage>(msg: &M) -> Result<Self, $crate::error::ParseError>{
+                let headers = msg.headers().get_all(Self::name());
+
+                $crate::http::header::from_comma_delimited(headers)
+                    .and_then(|items| {
+                        if items.is_empty() {
+                            Err($crate::error::ParseError::Header)
+                        } else {
+                            Ok($id(items))
+                        }
+                    })
             }
         }
 
@@ -159,6 +175,7 @@ macro_rules! common_header {
         impl $crate::http::header::IntoHeaderValue for $id {
             type Error = $crate::http::header::InvalidHeaderValue;
 
+            #[inline]
             fn try_into_value(self) -> Result<$crate::http::header::HeaderValue, Self::Error> {
                 use ::core::fmt::Write;
                 let mut writer = $crate::http::header::Writer::new();
@@ -197,6 +214,7 @@ macro_rules! common_header {
         impl $crate::http::header::IntoHeaderValue for $id {
             type Error = $crate::http::header::InvalidHeaderValue;
 
+            #[inline]
             fn try_into_value(self) -> Result<$crate::http::header::HeaderValue, Self::Error> {
                 self.0.try_into_value()
             }
@@ -251,6 +269,7 @@ macro_rules! common_header {
         impl $crate::http::header::IntoHeaderValue for $id {
             type Error = $crate::http::header::InvalidHeaderValue;
 
+            #[inline]
             fn try_into_value(self) -> Result<$crate::http::header::HeaderValue, Self::Error> {
                 use ::core::fmt::Write;
                 let mut writer = $crate::http::header::Writer::new();
diff --git a/src/http/header/mod.rs b/src/http/header/mod.rs
index 750f0e5b9..98548dadd 100644
--- a/src/http/header/mod.rs
+++ b/src/http/header/mod.rs
@@ -17,9 +17,9 @@ use bytes::{Bytes, BytesMut};
 // - header parsing utils
 pub use actix_http::http::header::*;
 
-mod accept_charset;
-// mod accept_encoding;
 mod accept;
+mod accept_charset;
+mod accept_encoding;
 mod accept_language;
 mod allow;
 mod cache_control;
@@ -46,9 +46,9 @@ mod preference;
 pub(crate) use macros::common_header_test;
 pub(crate) use macros::{common_header, common_header_test_module};
 
-pub use self::accept_charset::AcceptCharset;
-//pub use self::accept_encoding::AcceptEncoding;
 pub use self::accept::Accept;
+pub use self::accept_charset::AcceptCharset;
+pub use self::accept_encoding::AcceptEncoding;
 pub use self::accept_language::AcceptLanguage;
 pub use self::allow::Allow;
 pub use self::cache_control::{CacheControl, CacheDirective};