lints: fix clippy lints

Fix all failing clippy lints for backports branch

src/body.rs

@@ -277,7 +277,7 @@ impl Body {
     pub async fn into_json<T: DeserializeOwned>(mut self) -> crate::Result<T> {
         let mut buf = Vec::with_capacity(1024);
         self.read_to_end(&mut buf).await?;
-        Ok(serde_json::from_slice(&buf).status(StatusCode::UnprocessableEntity)?)
+        serde_json::from_slice(&buf).status(StatusCode::UnprocessableEntity)
     }
 
     /// Creates a `Body` from a type, serializing it using form encoding.
@@ -346,7 +346,7 @@ impl Body {
     /// ```
     pub async fn into_form<T: DeserializeOwned>(self) -> crate::Result<T> {
         let s = self.into_string().await?;
-        Ok(serde_urlencoded::from_str(&s).status(StatusCode::UnprocessableEntity)?)
+        serde_urlencoded::from_str(&s).status(StatusCode::UnprocessableEntity)
     }
 
     /// Create a `Body` from a file.
@@ -507,7 +507,7 @@ impl AsyncRead for Body {
         cx: &mut Context<'_>,
         buf: &mut [u8],
     ) -> Poll<io::Result<usize>> {
-        let mut buf = match self.length {
+        let buf = match self.length {
             None => buf,
             Some(length) if length == self.bytes_read => return Poll::Ready(Ok(0)),
             Some(length) => {
@@ -516,7 +516,7 @@ impl AsyncRead for Body {
             }
         };
 
-        let bytes = ready!(Pin::new(&mut self.reader).poll_read(cx, &mut buf))?;
+        let bytes = ready!(Pin::new(&mut self.reader).poll_read(cx, buf))?;
         self.bytes_read += bytes;
         Poll::Ready(Ok(bytes))
     }
@@ -551,7 +551,7 @@ async fn peek_mime(file: &mut async_std::fs::File) -> io::Result<Option<Mime>> {
 /// This is useful for plain-text formats such as HTML and CSS.
 #[cfg(all(feature = "fs", not(target_os = "unknown")))]
 fn guess_ext(path: &std::path::Path) -> Option<Mime> {
-    let ext = path.extension().map(|p| p.to_str()).flatten();
+    let ext = path.extension().and_then(|p| p.to_str());
     ext.and_then(Mime::from_extension)
 }
 
@@ -565,7 +565,7 @@ mod test {
     async fn json_status() {
         #[derive(Debug, Deserialize)]
         struct Foo {
-            inner: String,
+            _inner: String,
         }
         let body = Body::empty();
         let res = body.into_json::<Foo>().await;
@@ -576,7 +576,7 @@ mod test {
     async fn form_status() {
         #[derive(Debug, Deserialize)]
         struct Foo {
-            inner: String,
+            _inner: String,
         }
         let body = Body::empty();
         let res = body.into_form::<Foo>().await;

src/cache/cache_control/cache_directive.rs

@@ -88,7 +88,7 @@ impl CacheDirective {
             return Ok(None);
         }
 
-        s.to_lowercase();
+        let s = s.to_lowercase();
         let mut parts = s.split('=');
         let next = parts.next().unwrap();
 

src/cache/clear_site_data/mod.rs

@@ -96,8 +96,8 @@ impl ClearSiteData {
         let mut output = String::new();
         for (n, etag) in self.entries.iter().enumerate() {
             match n {
-                0 => write!(output, "{}", etag.to_string()).unwrap(),
-                _ => write!(output, ", {}", etag.to_string()).unwrap(),
+                0 => write!(output, "{}", etag).unwrap(),
+                _ => write!(output, ", {}", etag).unwrap(),
             };
         }
 

src/conditional/if_match.rs

@@ -88,8 +88,8 @@ impl IfMatch {
         let mut output = String::new();
         for (n, etag) in self.entries.iter().enumerate() {
             match n {
-                0 => write!(output, "{}", etag.to_string()).unwrap(),
-                _ => write!(output, ", {}", etag.to_string()).unwrap(),
+                0 => write!(output, "{}", etag).unwrap(),
+                _ => write!(output, ", {}", etag).unwrap(),
             };
         }
 

src/conditional/if_none_match.rs

@@ -94,8 +94,8 @@ impl IfNoneMatch {
         let mut output = String::new();
         for (n, etag) in self.entries.iter().enumerate() {
             match n {
-                0 => write!(output, "{}", etag.to_string()).unwrap(),
-                _ => write!(output, ", {}", etag.to_string()).unwrap(),
+                0 => write!(output, "{}", etag).unwrap(),
+                _ => write!(output, ", {}", etag).unwrap(),
             };
         }
 

src/error.rs

@@ -159,7 +159,7 @@ impl Error {
 
     /// Retrieves a reference to the type name of the error, if available.
     pub fn type_name(&self) -> Option<&str> {
-        self.type_name.as_deref()
+        self.type_name
     }
 
     /// Converts anything which implements `Display` into an `http_types::Error`.

src/method.rs

@@ -391,7 +391,7 @@ impl Serialize for Method {
     where
         S: Serializer,
     {
-        serializer.serialize_str(&self.to_string())
+        serializer.serialize_str(self.as_ref())
     }
 }
 

src/mime/parse.rs

@@ -153,12 +153,12 @@ fn is_http_whitespace_char(c: char) -> bool {
 
 /// [code point sequence collection](https://infra.spec.whatwg.org/#collect-a-sequence-of-code-points)
 fn collect_code_point_sequence_char(input: &str, delimiter: char) -> (&str, &str) {
-    input.split_at(input.find(delimiter).unwrap_or_else(|| input.len()))
+    input.split_at(input.find(delimiter).unwrap_or(input.len()))
 }
 
 /// [code point sequence collection](https://infra.spec.whatwg.org/#collect-a-sequence-of-code-points)
 fn collect_code_point_sequence_slice<'a>(input: &'a str, delimiter: &[char]) -> (&'a str, &'a str) {
-    input.split_at(input.find(delimiter).unwrap_or_else(|| input.len()))
+    input.split_at(input.find(delimiter).unwrap_or(input.len()))
 }
 
 /// [HTTP quoted string collection](https://fetch.spec.whatwg.org/#collect-an-http-quoted-string)

src/trace/server_timing/parse.rs

@@ -65,7 +65,7 @@ fn parse_entry(s: &str) -> crate::Result<Metric> {
                 let millis: f64 = value.parse().map_err(|_| {
                         format_err!("Server timing duration params must be a valid double-precision floating-point number.")
                     })?;
-                dur = Some(Duration::from_secs_f64(millis / 1000.0));
+                dur = Some(Duration::from_secs_f64(millis) / 1000);
             }
             "desc" => {
                 // Ensure quotes line up, and strip them from the resulting output

src/version.rs

@@ -24,7 +24,7 @@ impl Serialize for Version {
     where
         S: Serializer,
     {
-        serializer.serialize_str(&self.to_string())
+        serializer.serialize_str(self.as_ref())
     }
 }