Various fixes in actix-web crate

src/app.rs

@@ -42,6 +42,7 @@ pub struct App<T, B> {
 impl App<AppEntry, Body> {
     /// Create application builder. Application can be configured with a builder-like pattern.
     #[allow(clippy::new_without_default)]
+    #[must_use]
     pub fn new() -> Self {
         let fref = Rc::new(RefCell::new(None));
         App {

src/app_service.rs

@@ -131,9 +131,9 @@ where
             let service = endpoint_fut.await?;
 
             // populate app data container from (async) data factories.
-            async_data_factories.iter().for_each(|factory| {
+            for factory in &async_data_factories {
                 factory.create(&mut app_data);
-            });
+            }
 
             Ok(AppInitService {
                 service,

src/config.rs

@@ -44,6 +44,7 @@ impl AppService {
     }
 
     /// Check if root is being configured
+    #[must_use]
     pub fn is_root(&self) -> bool {
         self.root
     }
@@ -72,11 +73,13 @@ impl AppService {
     }
 
     /// Service configuration
+    #[must_use]
     pub fn config(&self) -> &AppConfig {
         &self.config
     }
 
     /// Default resource
+    #[must_use]
     pub fn default_service(&self) -> Rc<HttpNewService> {
         self.default.clone()
     }
@@ -129,16 +132,19 @@ impl AppConfig {
     /// documentation for more information.
     ///
     /// By default host name is set to a "localhost" value.
+    #[must_use]
     pub fn host(&self) -> &str {
         &self.host
     }
 
     /// Returns true if connection is secure(https)
+    #[must_use]
     pub fn secure(&self) -> bool {
         self.secure
     }
 
     /// Returns the socket address of the local half of this TCP connection
+    #[must_use]
     pub fn local_addr(&self) -> SocketAddr {
         self.addr
     }

src/data.rs

@@ -72,11 +72,13 @@ impl<T> Data<T> {
     }
 
     /// Get reference to inner app data.
+    #[must_use]
     pub fn get_ref(&self) -> &T {
         self.0.as_ref()
     }
 
     /// Convert to the internal Arc<T>
+    #[must_use]
     pub fn into_inner(self) -> Arc<T> {
         self.0
     }

src/error/error.rs

@@ -20,16 +20,19 @@ pub struct Error {
 
 impl Error {
     /// Returns the reference to the underlying `ResponseError`.
+    #[must_use]
     pub fn as_response_error(&self) -> &dyn ResponseError {
         self.cause.as_ref()
     }
 
     /// Similar to `as_response_error` but downcasts.
+    #[must_use]
     pub fn as_error<T: ResponseError + 'static>(&self) -> Option<&T> {
         <dyn ResponseError>::downcast_ref(self.cause.as_ref())
     }
 
     /// Shortcut for creating an `HttpResponse`.
+    #[must_use]
     pub fn error_response(&self) -> HttpResponse {
         self.cause.error_response()
     }

src/guard.rs

@@ -195,57 +195,68 @@ impl Guard for MethodGuard {
 }
 
 /// Guard to match *GET* HTTP method.
+#[must_use]
 pub fn Get() -> MethodGuard {
     MethodGuard(http::Method::GET)
 }
 
 /// Predicate to match *POST* HTTP method.
+#[must_use]
 pub fn Post() -> MethodGuard {
     MethodGuard(http::Method::POST)
 }
 
 /// Predicate to match *PUT* HTTP method.
+#[must_use]
 pub fn Put() -> MethodGuard {
     MethodGuard(http::Method::PUT)
 }
 
 /// Predicate to match *DELETE* HTTP method.
+#[must_use]
 pub fn Delete() -> MethodGuard {
     MethodGuard(http::Method::DELETE)
 }
 
 /// Predicate to match *HEAD* HTTP method.
+#[must_use]
 pub fn Head() -> MethodGuard {
     MethodGuard(http::Method::HEAD)
 }
 
 /// Predicate to match *OPTIONS* HTTP method.
+#[must_use]
 pub fn Options() -> MethodGuard {
     MethodGuard(http::Method::OPTIONS)
 }
 
 /// Predicate to match *CONNECT* HTTP method.
+#[must_use]
 pub fn Connect() -> MethodGuard {
     MethodGuard(http::Method::CONNECT)
 }
 
 /// Predicate to match *PATCH* HTTP method.
+#[must_use]
 pub fn Patch() -> MethodGuard {
     MethodGuard(http::Method::PATCH)
 }
 
 /// Predicate to match *TRACE* HTTP method.
+#[must_use]
 pub fn Trace() -> MethodGuard {
     MethodGuard(http::Method::TRACE)
 }
 
 /// Predicate to match specified HTTP method.
+#[must_use]
 pub fn Method(method: http::Method) -> MethodGuard {
     MethodGuard(method)
 }
 
 /// Return predicate that matches if request contains specified header and
 /// value.
+#[must_use]
 pub fn Header(name: &'static str, value: &'static str) -> HeaderGuard {
     HeaderGuard(
         header::HeaderName::try_from(name).unwrap(),

src/http/header/accept.rs

@@ -126,26 +126,31 @@ crate::__define_common_header! {
 
 impl Accept {
     /// Construct `Accept: */*`.
+    #[must_use]
     pub fn star() -> Accept {
         Accept(vec![qitem(mime::STAR_STAR)])
     }
 
     /// Construct `Accept: application/json`.
+    #[must_use]
     pub fn json() -> Accept {
         Accept(vec![qitem(mime::APPLICATION_JSON)])
     }
 
     /// Construct `Accept: text/*`.
+    #[must_use]
     pub fn text() -> Accept {
         Accept(vec![qitem(mime::TEXT_STAR)])
     }
 
     /// Construct `Accept: image/*`.
+    #[must_use]
     pub fn image() -> Accept {
         Accept(vec![qitem(mime::IMAGE_STAR)])
     }
 
     /// Construct `Accept: text/html`.
+    #[must_use]
     pub fn html() -> Accept {
         Accept(vec![qitem(mime::TEXT_HTML)])
     }
@@ -154,6 +159,7 @@ impl Accept {
     /// [q-factor weighting] and specificity.
     ///
     /// [q-factor weighting]: https://tools.ietf.org/html/rfc7231#section-5.3.2
+    #[must_use]
     pub fn mime_precedence(&self) -> Vec<Mime> {
         let mut types = self.0.clone();
 
@@ -204,6 +210,7 @@ impl Accept {
     /// Returns `None` if contained list is empty.
     ///
     /// [q-factor weighting]: https://tools.ietf.org/html/rfc7231#section-5.3.2
+    #[must_use]
     pub fn mime_preference(&self) -> Option<Mime> {
         let types = self.mime_precedence();
         types.first().cloned()

src/http/header/content_disposition.rs

@@ -101,24 +101,28 @@ pub enum DispositionParam {
 impl DispositionParam {
     /// Returns `true` if the parameter is [`Name`](DispositionParam::Name).
     #[inline]
+    #[must_use]
     pub fn is_name(&self) -> bool {
         self.as_name().is_some()
     }
 
     /// Returns `true` if the parameter is [`Filename`](DispositionParam::Filename).
     #[inline]
+    #[must_use]
     pub fn is_filename(&self) -> bool {
         self.as_filename().is_some()
     }
 
     /// Returns `true` if the parameter is [`FilenameExt`](DispositionParam::FilenameExt).
     #[inline]
+    #[must_use]
     pub fn is_filename_ext(&self) -> bool {
         self.as_filename_ext().is_some()
     }
 
     /// Returns `true` if the parameter is [`Unknown`](DispositionParam::Unknown) and the `name`
     #[inline]
+    #[must_use]
     /// matches.
     pub fn is_unknown<T: AsRef<str>>(&self, name: T) -> bool {
         self.as_unknown(name).is_some()
@@ -127,12 +131,14 @@ impl DispositionParam {
     /// Returns `true` if the parameter is [`UnknownExt`](DispositionParam::UnknownExt) and the
     /// `name` matches.
     #[inline]
+    #[must_use]
     pub fn is_unknown_ext<T: AsRef<str>>(&self, name: T) -> bool {
         self.as_unknown_ext(name).is_some()
     }
 
     /// Returns the name if applicable.
     #[inline]
+    #[must_use]
     pub fn as_name(&self) -> Option<&str> {
         match self {
             DispositionParam::Name(ref name) => Some(name.as_str()),
@@ -142,6 +148,7 @@ impl DispositionParam {
 
     /// Returns the filename if applicable.
     #[inline]
+    #[must_use]
     pub fn as_filename(&self) -> Option<&str> {
         match self {
             DispositionParam::Filename(ref filename) => Some(filename.as_str()),
@@ -151,6 +158,7 @@ impl DispositionParam {
 
     /// Returns the filename* if applicable.
     #[inline]
+    #[must_use]
     pub fn as_filename_ext(&self) -> Option<&ExtendedValue> {
         match self {
             DispositionParam::FilenameExt(ref value) => Some(value),
@@ -161,6 +169,7 @@ impl DispositionParam {
     /// Returns the value of the unrecognized regular parameter if it is
     /// [`Unknown`](DispositionParam::Unknown) and the `name` matches.
     #[inline]
+    #[must_use]
     pub fn as_unknown<T: AsRef<str>>(&self, name: T) -> Option<&str> {
         match self {
             DispositionParam::Unknown(ref ext_name, ref value)
@@ -175,6 +184,7 @@ impl DispositionParam {
     /// Returns the value of the unrecognized extended parameter if it is
     /// [`Unknown`](DispositionParam::Unknown) and the `name` matches.
     #[inline]
+    #[must_use]
     pub fn as_unknown_ext<T: AsRef<str>>(&self, name: T) -> Option<&ExtendedValue> {
         match self {
             DispositionParam::UnknownExt(ref ext_name, ref value)
@@ -386,21 +396,25 @@ impl ContentDisposition {
     }
 
     /// Returns `true` if it is [`Inline`](DispositionType::Inline).
+    #[must_use]
     pub fn is_inline(&self) -> bool {
         matches!(self.disposition, DispositionType::Inline)
     }
 
     /// Returns `true` if it is [`Attachment`](DispositionType::Attachment).
+    #[must_use]
     pub fn is_attachment(&self) -> bool {
         matches!(self.disposition, DispositionType::Attachment)
     }
 
     /// Returns `true` if it is [`FormData`](DispositionType::FormData).
+    #[must_use]
     pub fn is_form_data(&self) -> bool {
         matches!(self.disposition, DispositionType::FormData)
     }
 
     /// Returns `true` if it is [`Ext`](DispositionType::Ext) and the `disp_type` matches.
+    #[must_use]
     pub fn is_ext(&self, disp_type: impl AsRef<str>) -> bool {
         matches!(
             self.disposition,
@@ -409,42 +423,39 @@ impl ContentDisposition {
     }
 
     /// Return the value of *name* if exists.
+    #[must_use]
     pub fn get_name(&self) -> Option<&str> {
-        self.parameters.iter().filter_map(|p| p.as_name()).next()
+        self.parameters.iter().find_map(DispositionParam::as_name)
     }
 
     /// Return the value of *filename* if exists.
+    #[must_use]
     pub fn get_filename(&self) -> Option<&str> {
         self.parameters
             .iter()
-            .filter_map(|p| p.as_filename())
+            .find_map(DispositionParam::as_filename)
-            .next()
     }
 
     /// Return the value of *filename\** if exists.
+    #[must_use]
     pub fn get_filename_ext(&self) -> Option<&ExtendedValue> {
         self.parameters
             .iter()
-            .filter_map(|p| p.as_filename_ext())
+            .find_map(DispositionParam::as_filename_ext)
-            .next()
     }
 
     /// Return the value of the parameter which the `name` matches.
+    #[must_use]
     pub fn get_unknown(&self, name: impl AsRef<str>) -> Option<&str> {
         let name = name.as_ref();
-        self.parameters
+        self.parameters.iter().find_map(|p| p.as_unknown(name))
-            .iter()
-            .filter_map(|p| p.as_unknown(name))
-            .next()
     }
 
     /// Return the value of the extended parameter which the `name` matches.
+    #[must_use]
     pub fn get_unknown_ext(&self, name: impl AsRef<str>) -> Option<&ExtendedValue> {
         let name = name.as_ref();
-        self.parameters
+        self.parameters.iter().find_map(|p| p.as_unknown_ext(name))
-            .iter()
-            .filter_map(|p| p.as_unknown_ext(name))
-            .next()
     }
 }
 

src/http/header/content_type.rs

@@ -63,6 +63,7 @@ impl ContentType {
     /// A constructor  to easily create a `Content-Type: application/json`
     /// header.
     #[inline]
+    #[must_use]
     pub fn json() -> ContentType {
         ContentType(mime::APPLICATION_JSON)
     }
@@ -70,18 +71,21 @@ impl ContentType {
     /// A constructor  to easily create a `Content-Type: text/plain;
     /// charset=utf-8` header.
     #[inline]
+    #[must_use]
     pub fn plaintext() -> ContentType {
         ContentType(mime::TEXT_PLAIN_UTF_8)
     }
 
     /// A constructor  to easily create a `Content-Type: text/html` header.
     #[inline]
+    #[must_use]
     pub fn html() -> ContentType {
         ContentType(mime::TEXT_HTML)
     }
 
     /// A constructor  to easily create a `Content-Type: text/xml` header.
     #[inline]
+    #[must_use]
     pub fn xml() -> ContentType {
         ContentType(mime::TEXT_XML)
     }
@@ -89,18 +93,21 @@ impl ContentType {
     /// A constructor  to easily create a `Content-Type:
     /// application/www-form-url-encoded` header.
     #[inline]
+    #[must_use]
     pub fn form_url_encoded() -> ContentType {
         ContentType(mime::APPLICATION_WWW_FORM_URLENCODED)
     }
 
     /// A constructor  to easily create a `Content-Type: image/jpeg` header.
     #[inline]
+    #[must_use]
     pub fn jpeg() -> ContentType {
         ContentType(mime::IMAGE_JPEG)
     }
 
     /// A constructor  to easily create a `Content-Type: image/png` header.
     #[inline]
+    #[must_use]
     pub fn png() -> ContentType {
         ContentType(mime::IMAGE_PNG)
     }
@@ -108,6 +115,7 @@ impl ContentType {
     /// A constructor  to easily create a `Content-Type:
     /// application/octet-stream` header.
     #[inline]
+    #[must_use]
     pub fn octet_stream() -> ContentType {
         ContentType(mime::APPLICATION_OCTET_STREAM)
     }

src/http/header/date.rs

@@ -38,6 +38,7 @@ crate::__define_common_header! {
 
 impl Date {
     /// Create a date instance set to the current system time
+    #[must_use]
     pub fn now() -> Date {
         Date(SystemTime::now().into())
     }

src/http/header/entity.rs

@@ -58,6 +58,7 @@ impl EntityTag {
     /// Constructs a new EntityTag.
     /// # Panics
     /// If the tag contains invalid characters.
+    #[must_use]
     pub fn new(weak: bool, tag: String) -> EntityTag {
         assert!(check_slice_validity(&tag), "Invalid tag: {:?}", tag);
         EntityTag { weak, tag }
@@ -66,6 +67,7 @@ impl EntityTag {
     /// Constructs a new weak EntityTag.
     /// # Panics
     /// If the tag contains invalid characters.
+    #[must_use]
     pub fn weak(tag: String) -> EntityTag {
         EntityTag::new(true, tag)
     }
@@ -73,11 +75,13 @@ impl EntityTag {
     /// Constructs a new strong EntityTag.
     /// # Panics
     /// If the tag contains invalid characters.
+    #[must_use]
     pub fn strong(tag: String) -> EntityTag {
         EntityTag::new(false, tag)
     }
 
     /// Get the tag.
+    #[must_use]
     pub fn tag(&self) -> &str {
         self.tag.as_ref()
     }
@@ -92,6 +96,7 @@ impl EntityTag {
 
     /// For strong comparison two entity-tags are equivalent if both are not
     /// weak and their opaque-tags match character-by-character.
+    #[must_use]
     pub fn strong_eq(&self, other: &EntityTag) -> bool {
         !self.weak && !other.weak && self.tag == other.tag
     }
@@ -99,16 +104,19 @@ impl EntityTag {
     /// For weak comparison two entity-tags are equivalent if their
     /// opaque-tags match character-by-character, regardless of either or
     /// both being tagged as "weak".
+    #[must_use]
     pub fn weak_eq(&self, other: &EntityTag) -> bool {
         self.tag == other.tag
     }
 
     /// The inverse of `EntityTag.strong_eq()`.
+    #[must_use]
     pub fn strong_ne(&self, other: &EntityTag) -> bool {
         !self.strong_eq(other)
     }
 
     /// The inverse of `EntityTag.weak_eq()`.
+    #[must_use]
     pub fn weak_ne(&self, other: &EntityTag) -> bool {
         !self.weak_eq(other)
     }

src/info.rs

@@ -2,6 +2,7 @@ use std::cell::Ref;
 
 use crate::dev::{AppConfig, RequestHead};
 use crate::http::header::{self, HeaderName};
+use crate::http::uri::{Authority, Scheme};
 
 const X_FORWARDED_FOR: &[u8] = b"x-forwarded-for";
 const X_FORWARDED_HOST: &[u8] = b"x-forwarded-host";
@@ -71,11 +72,11 @@ impl ConnectionInfo {
                 .get(&HeaderName::from_lowercase(X_FORWARDED_PROTO).unwrap())
             {
                 if let Ok(h) = h.to_str() {
-                    scheme = h.split(',').next().map(|v| v.trim());
+                    scheme = h.split(',').next().map(str::trim);
                 }
             }
             if scheme.is_none() {
-                scheme = req.uri.scheme().map(|a| a.as_str());
+                scheme = req.uri.scheme().map(Scheme::as_str);
                 if scheme.is_none() && cfg.secure() {
                     scheme = Some("https")
                 }
@@ -89,7 +90,7 @@ impl ConnectionInfo {
                 .get(&HeaderName::from_lowercase(X_FORWARDED_HOST).unwrap())
             {
                 if let Ok(h) = h.to_str() {
-                    host = h.split(',').next().map(|v| v.trim());
+                    host = h.split(',').next().map(str::trim);
                 }
             }
             if host.is_none() {
@@ -97,7 +98,7 @@ impl ConnectionInfo {
                     host = h.to_str().ok();
                 }
                 if host.is_none() {
-                    host = req.uri.authority().map(|a| a.as_str());
+                    host = req.uri.authority().map(Authority::as_str);
                     if host.is_none() {
                         host = Some(cfg.host());
                     }
@@ -114,7 +115,7 @@ impl ConnectionInfo {
                 .get(&HeaderName::from_lowercase(X_FORWARDED_FOR).unwrap())
             {
                 if let Ok(h) = h.to_str() {
-                    realip_remote_addr = h.split(',').next().map(|v| v.trim());
+                    realip_remote_addr = h.split(',').next().map(str::trim);
                 }
             }
         }
@@ -123,7 +124,7 @@ impl ConnectionInfo {
             remote_addr,
             scheme: scheme.unwrap_or("http").to_owned(),
             host: host.unwrap_or("localhost").to_owned(),
-            realip_remote_addr: realip_remote_addr.map(|s| s.to_owned()),
+            realip_remote_addr: realip_remote_addr.map(str::to_owned),
         }
     }
 
@@ -135,6 +136,7 @@ impl ConnectionInfo {
     /// - X-Forwarded-Proto
     /// - Uri
     #[inline]
+    #[must_use]
     pub fn scheme(&self) -> &str {
         &self.scheme
     }
@@ -148,6 +150,7 @@ impl ConnectionInfo {
     /// - Host
     /// - Uri
     /// - Server hostname
+    #[must_use]
     pub fn host(&self) -> &str {
         &self.host
     }
@@ -155,12 +158,9 @@ impl ConnectionInfo {
     /// remote_addr address of the request.
     ///
     /// Get remote_addr address from socket address
+    #[must_use]
     pub fn remote_addr(&self) -> Option<&str> {
-        if let Some(ref remote_addr) = self.remote_addr {
+        self.remote_addr.as_ref().map(String::as_ref)
-            Some(remote_addr)
-        } else {
-            None
-        }
     }
     /// Real ip remote addr of client initiated HTTP request.
     ///
@@ -176,13 +176,12 @@ impl ConnectionInfo {
     /// address explicitly, use
     /// [`HttpRequest::peer_addr()`](super::web::HttpRequest::peer_addr()) instead.
     #[inline]
+    #[must_use]
     pub fn realip_remote_addr(&self) -> Option<&str> {
         if let Some(ref r) = self.realip_remote_addr {
             Some(r)
-        } else if let Some(ref remote_addr) = self.remote_addr {
-            Some(remote_addr)
         } else {
-            None
+            self.remote_addr.as_ref().map(String::as_ref)
         }
     }
 }

src/middleware/compress.rs

@@ -43,6 +43,7 @@ pub struct Compress(ContentEncoding);
 
 impl Compress {
     /// Create new `Compress` middleware with the specified encoding.
+    #[must_use]
     pub fn new(encoding: ContentEncoding) -> Self {
         Compress(encoding)
     }
@@ -200,8 +201,7 @@ impl AcceptEncoding {
         let mut encodings = raw
             .replace(' ', "")
             .split(',')
-            .map(|l| AcceptEncoding::new(l))
+            .filter_map(|l| AcceptEncoding::new(l))
-            .flatten()
             .collect::<Vec<_>>();
 
         encodings.sort();

src/request.rs

@@ -65,6 +65,7 @@ impl HttpRequest {
 impl HttpRequest {
     /// This method returns reference to the request head
     #[inline]
+    #[must_use]
     pub fn head(&self) -> &RequestHead {
         &self.inner.head
     }
@@ -78,23 +79,27 @@ impl HttpRequest {
 
     /// Request's uri.
     #[inline]
+    #[must_use]
     pub fn uri(&self) -> &Uri {
         &self.head().uri
     }
 
     /// Read the Request method.
     #[inline]
+    #[must_use]
     pub fn method(&self) -> &Method {
         &self.head().method
     }
 
     /// Read the Request Version.
     #[inline]
+    #[must_use]
     pub fn version(&self) -> Version {
         self.head().version
     }
 
     #[inline]
+    #[must_use]
     /// Returns request's headers.
     pub fn headers(&self) -> &HeaderMap {
         &self.head().headers
@@ -102,6 +107,7 @@ impl HttpRequest {
 
     /// The target path of this Request.
     #[inline]
+    #[must_use]
     pub fn path(&self) -> &str {
         self.head().uri.path()
     }
@@ -110,12 +116,9 @@ impl HttpRequest {
     ///
     /// E.g., id=10
     #[inline]
+    #[must_use]
     pub fn query_string(&self) -> &str {
-        if let Some(query) = self.uri().query().as_ref() {
+        self.uri().query().unwrap_or_default()
-            query
-        } else {
-            ""
-        }
     }
 
     /// Get a reference to the Path parameters.
@@ -125,6 +128,7 @@ impl HttpRequest {
     /// where the identifier can be used later in a request handler to
     /// access the matched value for that segment.
     #[inline]
+    #[must_use]
     pub fn match_info(&self) -> &Path<Url> {
         &self.inner.path
     }
@@ -141,6 +145,7 @@ impl HttpRequest {
     ///
     /// Returns a None when no resource is fully matched, including default services.
     #[inline]
+    #[must_use]
     pub fn match_pattern(&self) -> Option<String> {
         self.resource_map().match_pattern(self.path())
     }
@@ -149,18 +154,21 @@ impl HttpRequest {
     ///
     /// Returns a None when no resource is fully matched, including default services.
     #[inline]
+    #[must_use]
     pub fn match_name(&self) -> Option<&str> {
         self.resource_map().match_name(self.path())
     }
 
     /// Request extensions
     #[inline]
+    #[must_use]
     pub fn extensions(&self) -> Ref<'_, Extensions> {
         self.head().extensions()
     }
 
     /// Mutable reference to a the request's extensions
     #[inline]
+    #[must_use]
     pub fn extensions_mut(&self) -> RefMut<'_, Extensions> {
         self.head().extensions_mut()
     }
@@ -201,6 +209,7 @@ impl HttpRequest {
     }
 
     #[inline]
+    #[must_use]
     /// Get a reference to a `ResourceMap` of current application.
     pub fn resource_map(&self) -> &ResourceMap {
         &self.app_state().rmap()
@@ -215,6 +224,7 @@ impl HttpRequest {
     ///
     /// Will only return None when called in unit tests.
     #[inline]
+    #[must_use]
     pub fn peer_addr(&self) -> Option<net::SocketAddr> {
         self.head().peer_addr
     }
@@ -224,12 +234,14 @@ impl HttpRequest {
     /// This method panics if request's extensions container is already
     /// borrowed.
     #[inline]
+    #[must_use]
     pub fn connection_info(&self) -> Ref<'_, ConnectionInfo> {
         ConnectionInfo::get(self.head(), self.app_config())
     }
 
     /// App config
     #[inline]
+    #[must_use]
     pub fn app_config(&self) -> &AppConfig {
         self.app_state().config()
     }
@@ -242,6 +254,7 @@ impl HttpRequest {
     /// ```ignore
     /// let opt_t = req.app_data::<Data<T>>();
     /// ```
+    #[must_use]
     pub fn app_data<T: 'static>(&self) -> Option<&T> {
         for container in self.inner.app_data.iter().rev() {
             if let Some(data) = container.get::<T>() {
@@ -282,11 +295,12 @@ impl HttpRequest {
 
     /// Return request cookie.
     #[cfg(feature = "cookies")]
+    #[must_use]
     pub fn cookie(&self, name: &str) -> Option<Cookie<'static>> {
         if let Ok(cookies) = self.cookies() {
             for cookie in cookies.iter() {
                 if cookie.name() == name {
-                    return Some(cookie.to_owned());
+                    return Some(cookie.clone());
                 }
             }
         }

src/resource.rs

@@ -474,7 +474,7 @@ impl Service<ServiceRequest> for ResourceService {
     actix_service::always_ready!();
 
     fn call(&self, mut req: ServiceRequest) -> Self::Future {
-        for route in self.routes.iter() {
+        for route in &self.routes {
             if route.check(&mut req) {
                 if let Some(ref app_data) = self.app_data {
                     req.add_data_container(app_data.clone());

src/response/builder.rs

@@ -42,6 +42,7 @@ pub struct HttpResponseBuilder {
 impl HttpResponseBuilder {
     #[inline]
     /// Create response builder
+    #[must_use]
     pub fn new(status: StatusCode) -> Self {
         Self {
             res: Some(Response::new(status)),
@@ -406,7 +407,7 @@ impl HttpResponseBuilder {
             return None;
         }
 
-        self.res.as_mut().map(|res| res.head_mut())
+        self.res.as_mut().map(Response::head_mut)
     }
 }
 

src/response/http_codes.rs

@@ -7,6 +7,7 @@ use crate::{HttpResponse, HttpResponseBuilder};
 macro_rules! static_resp {
     ($name:ident, $status:expr) => {
         #[allow(non_snake_case, missing_docs)]
+        #[must_use]
         pub fn $name() -> HttpResponseBuilder {
             HttpResponseBuilder::new($status)
         }

src/response/response.rs

@@ -33,11 +33,13 @@ pub struct HttpResponse<B = AnyBody> {
 impl HttpResponse<AnyBody> {
     /// Create HTTP response builder with specific status.
     #[inline]
+    #[must_use]
     pub fn build(status: StatusCode) -> HttpResponseBuilder {
         HttpResponseBuilder::new(status)
     }
 
     /// Create a response.
+    #[must_use]
     #[inline]
     pub fn new(status: StatusCode) -> Self {
         Self {
@@ -48,6 +50,7 @@ impl HttpResponse<AnyBody> {
 
     /// Create an error response.
     #[inline]
+    #[must_use]
     pub fn from_error(error: impl Into<Error>) -> Self {
         error.into().as_response_error().error_response()
     }
@@ -129,10 +132,7 @@ impl<B> HttpResponse<B> {
     pub fn del_cookie(&mut self, name: &str) -> usize {
         let headers = self.headers_mut();
 
-        let vals: Vec<HeaderValue> = headers
+        let vals: Vec<HeaderValue> = headers.get_all(header::SET_COOKIE).cloned().collect();
-            .get_all(header::SET_COOKIE)
-            .map(|v| v.to_owned())
-            .collect();
 
         headers.remove(header::SET_COOKIE);
 

src/rmap.rs

@@ -17,6 +17,7 @@ pub struct ResourceMap {
 }
 
 impl ResourceMap {
+    #[must_use]
     pub fn new(root: ResourceDef) -> Self {
         ResourceMap {
             root,

src/route.rs

@@ -28,6 +28,7 @@ pub struct Route {
 impl Route {
     /// Create new route which matches any request.
     #[allow(clippy::new_without_default)]
+    #[must_use]
     pub fn new() -> Route {
         Route {
             service: boxed::factory(HandlerService::new(HttpResponse::NotFound)),
@@ -101,6 +102,7 @@ impl Route {
     /// );
     /// # }
     /// ```
+    #[must_use]
     pub fn method(mut self, method: Method) -> Self {
         Rc::get_mut(&mut self.guards)
             .unwrap()

src/scope.rs

@@ -70,6 +70,7 @@ pub struct Scope<T = ScopeEndpoint> {
 
 impl Scope {
     /// Create a new scope
+    #[must_use]
     pub fn new(path: &str) -> Scope {
         let fref = Rc::new(RefCell::new(None));
         Scope {

src/server.rs

@@ -292,15 +292,15 @@ where
                     let c = cfg.lock().unwrap();
                     let host = c.host.clone().unwrap_or_else(|| format!("{}", addr));
 
-                    let svc = HttpService::build()
+                    let mut svc = HttpService::build()
                         .keep_alive(c.keep_alive)
                         .client_timeout(c.client_timeout)
                         .local_addr(addr);
 
-                    let svc = if let Some(handler) = on_connect_fn.clone() {
+                    if let Some(handler) = on_connect_fn.clone() {
-                        svc.on_connect_ext(move |io: &_, ext: _| (handler)(io as &dyn Any, ext))
+                        svc = svc.on_connect_ext(move |io: &_, ext: _| {
-                    } else {
+                            (handler)(io as &dyn Any, ext)
-                        svc
+                        })
                     };
 
                     let fac = factory()
@@ -461,8 +461,9 @@ where
             }
         }
 
-        if !success {
+        if success {
-            if let Some(e) = err.take() {
+            Ok(sockets)
+        } else if let Some(e) = err.take() {
             Err(e)
         } else {
             Err(io::Error::new(
@@ -470,9 +471,6 @@ where
                 "Can not bind to address.",
             ))
         }
-        } else {
-            Ok(sockets)
-        }
     }
 
     #[cfg(feature = "openssl")]
@@ -537,15 +535,14 @@ where
             );
 
             fn_service(|io: UnixStream| async { Ok((io, Protocol::Http1, None)) }).and_then({
-                let svc = HttpService::build()
+                let mut svc = HttpService::build()
                     .keep_alive(c.keep_alive)
                     .client_timeout(c.client_timeout);
 
-                let svc = if let Some(handler) = on_connect_fn.clone() {
+                if let Some(handler) = on_connect_fn.clone() {
-                    svc.on_connect_ext(move |io: &_, ext: _| (&*handler)(io as &dyn Any, ext))
+                    svc = svc
-                } else {
+                        .on_connect_ext(move |io: &_, ext: _| (&*handler)(io as &dyn Any, ext));
-                    svc
+                }
-                };
 
                 let fac = factory()
                     .into_factory()

src/service.rs

@@ -76,11 +76,13 @@ impl ServiceRequest {
 
     /// Deconstruct request into parts
     #[inline]
+    #[must_use]
     pub fn into_parts(self) -> (HttpRequest, Payload) {
         (self.req, self.payload)
     }
 
     /// Construct request from parts.
+    #[must_use]
     pub fn from_parts(req: HttpRequest, payload: Payload) -> Self {
         Self { req, payload }
     }
@@ -88,6 +90,7 @@ impl ServiceRequest {
     /// Construct request from request.
     ///
     /// The returned `ServiceRequest` would have no payload.
+    #[must_use]
     pub fn from_request(req: HttpRequest) -> Self {
         ServiceRequest {
             req,
@@ -111,6 +114,7 @@ impl ServiceRequest {
 
     /// This method returns reference to the request head
     #[inline]
+    #[must_use]
     pub fn head(&self) -> &RequestHead {
         &self.req.head()
     }
@@ -123,29 +127,34 @@ impl ServiceRequest {
 
     /// Request's uri.
     #[inline]
+    #[must_use]
     pub fn uri(&self) -> &Uri {
         &self.head().uri
     }
 
     /// Read the Request method.
     #[inline]
+    #[must_use]
     pub fn method(&self) -> &Method {
         &self.head().method
     }
 
     /// Read the Request Version.
     #[inline]
+    #[must_use]
     pub fn version(&self) -> Version {
         self.head().version
     }
 
     #[inline]
+    #[must_use]
     /// Returns request's headers.
     pub fn headers(&self) -> &HeaderMap {
         &self.head().headers
     }
 
     #[inline]
+    #[must_use]
     /// Returns mutable request's headers.
     pub fn headers_mut(&mut self) -> &mut HeaderMap {
         &mut self.head_mut().headers
@@ -153,6 +162,7 @@ impl ServiceRequest {
 
     /// The target path of this Request.
     #[inline]
+    #[must_use]
     pub fn path(&self) -> &str {
         self.head().uri.path()
     }
@@ -161,12 +171,9 @@ impl ServiceRequest {
     ///
     /// E.g., id=10
     #[inline]
+    #[must_use]
     pub fn query_string(&self) -> &str {
-        if let Some(query) = self.uri().query().as_ref() {
+        self.uri().query().unwrap_or_default()
-            query
-        } else {
-            ""
-        }
     }
 
     /// Peer socket address.
@@ -178,12 +185,14 @@ impl ServiceRequest {
     ///
     /// Will only return None when called in unit tests.
     #[inline]
+    #[must_use]
     pub fn peer_addr(&self) -> Option<net::SocketAddr> {
         self.head().peer_addr
     }
 
     /// Get *ConnectionInfo* for the current request.
     #[inline]
+    #[must_use]
     pub fn connection_info(&self) -> Ref<'_, ConnectionInfo> {
         ConnectionInfo::get(self.head(), &*self.app_config())
     }
@@ -195,29 +204,34 @@ impl ServiceRequest {
     /// where the identifier can be used later in a request handler to
     /// access the matched value for that segment.
     #[inline]
+    #[must_use]
     pub fn match_info(&self) -> &Path<Url> {
         self.req.match_info()
     }
 
     /// Counterpart to [`HttpRequest::match_name`](super::HttpRequest::match_name()).
     #[inline]
+    #[must_use]
     pub fn match_name(&self) -> Option<&str> {
         self.req.match_name()
     }
 
     /// Counterpart to [`HttpRequest::match_pattern`](super::HttpRequest::match_pattern()).
     #[inline]
+    #[must_use]
     pub fn match_pattern(&self) -> Option<String> {
         self.req.match_pattern()
     }
 
     #[inline]
+    #[must_use]
     /// Get a mutable reference to the Path parameters.
     pub fn match_info_mut(&mut self) -> &mut Path<Url> {
         self.req.match_info_mut()
     }
 
     #[inline]
+    #[must_use]
     /// Get a reference to a `ResourceMap` of current application.
     pub fn resource_map(&self) -> &ResourceMap {
         self.req.resource_map()
@@ -225,11 +239,13 @@ impl ServiceRequest {
 
     /// Service configuration
     #[inline]
+    #[must_use]
     pub fn app_config(&self) -> &AppConfig {
         self.req.app_config()
     }
 
     /// Counterpart to [`HttpRequest::app_data`](super::HttpRequest::app_data()).
+    #[must_use]
     pub fn app_data<T: 'static>(&self) -> Option<&T> {
         for container in self.req.inner.app_data.iter().rev() {
             if let Some(data) = container.get::<T>() {
@@ -247,6 +263,7 @@ impl ServiceRequest {
 
     /// Return request cookie.
     #[cfg(feature = "cookies")]
+    #[must_use]
     pub fn cookie(&self, name: &str) -> Option<Cookie<'static>> {
         self.req.cookie(name)
     }
@@ -475,6 +492,7 @@ impl WebService {
     /// Set service name.
     ///
     /// Name is used for url generation.
+    #[must_use]
     pub fn name(mut self, name: &str) -> Self {
         self.name = Some(name.to_string());
         self

src/test.rs

@@ -31,12 +31,14 @@ use crate::{
 };
 
 /// Create service that always responds with `HttpResponse::Ok()` and no body.
+#[must_use]
 pub fn ok_service(
 ) -> impl Service<ServiceRequest, Response = ServiceResponse<Body>, Error = Error> {
     default_service(StatusCode::OK)
 }
 
 /// Create service that always responds with given status code and no body.
+#[must_use]
 pub fn default_service(
     status_code: StatusCode,
 ) -> impl Service<ServiceRequest, Response = ServiceResponse<Body>, Error = Error> {
@@ -398,31 +400,37 @@ impl Default for TestRequest {
 #[allow(clippy::wrong_self_convention)]
 impl TestRequest {
     /// Create TestRequest and set request uri
+    #[must_use]
     pub fn with_uri(path: &str) -> TestRequest {
         TestRequest::default().uri(path)
     }
 
     /// Create TestRequest and set method to `Method::GET`
+    #[must_use]
     pub fn get() -> TestRequest {
         TestRequest::default().method(Method::GET)
     }
 
     /// Create TestRequest and set method to `Method::POST`
+    #[must_use]
     pub fn post() -> TestRequest {
         TestRequest::default().method(Method::POST)
     }
 
     /// Create TestRequest and set method to `Method::PUT`
+    #[must_use]
     pub fn put() -> TestRequest {
         TestRequest::default().method(Method::PUT)
     }
 
     /// Create TestRequest and set method to `Method::PATCH`
+    #[must_use]
     pub fn patch() -> TestRequest {
         TestRequest::default().method(Method::PATCH)
     }
 
     /// Create TestRequest and set method to `Method::DELETE`
+    #[must_use]
     pub fn delete() -> TestRequest {
         TestRequest::default().method(Method::DELETE)
     }

src/types/form.rs

@@ -1,6 +1,7 @@
 //! For URL encoded form helper documentation, see [`Form`].
 
 use std::{
+    borrow::Cow,
     fmt,
     future::Future,
     ops,
@@ -223,12 +224,14 @@ pub struct FormConfig {
 
 impl FormConfig {
     /// Set maximum accepted payload size. By default this limit is 16kB.
+    #[must_use]
     pub fn limit(mut self, limit: usize) -> Self {
         self.limit = limit;
         self
     }
 
     /// Set custom error handler
+    #[must_use]
     pub fn error_handler<F>(mut self, f: F) -> Self
     where
         F: Fn(UrlencodedError, &HttpRequest) -> Error + 'static,
@@ -325,6 +328,7 @@ impl<T> UrlEncoded<T> {
     }
 
     /// Set maximum accepted payload size. The default limit is 256kB.
+    #[must_use]
     pub fn limit(mut self, limit: usize) -> Self {
         self.limit = limit;
         self
@@ -380,7 +384,7 @@ where
                 } else {
                     let body = encoding
                         .decode_without_bom_handling_and_without_replacement(&body)
-                        .map(|s| s.into_owned())
+                        .map(Cow::into_owned)
                         .ok_or(UrlencodedError::Encoding)?;
 
                     serde_urlencoded::from_str::<T>(&body).map_err(UrlencodedError::Parse)

src/types/json.rs

@@ -241,12 +241,14 @@ pub struct JsonConfig {
 
 impl JsonConfig {
     /// Set maximum accepted payload size. By default this limit is 2MB.
+    #[must_use]
     pub fn limit(mut self, limit: usize) -> Self {
         self.limit = limit;
         self
     }
 
     /// Set custom error handler.
+    #[must_use]
     pub fn error_handler<F>(mut self, f: F) -> Self
     where
         F: Fn(JsonPayloadError, &HttpRequest) -> Error + Send + Sync + 'static,
@@ -256,6 +258,7 @@ impl JsonConfig {
     }
 
     /// Set predicate for allowed content types.
+    #[must_use]
     pub fn content_type<F>(mut self, predicate: F) -> Self
     where
         F: Fn(mime::Mime) -> bool + Send + Sync + 'static,
@@ -365,6 +368,7 @@ where
     }
 
     /// Set maximum accepted payload size. The default limit is 2MB.
+    #[must_use]
     pub fn limit(self, limit: usize) -> Self {
         match self {
             JsonBody::Body {

src/types/path.rs

@@ -103,8 +103,7 @@ where
     fn from_request(req: &HttpRequest, _: &mut Payload) -> Self::Future {
         let error_handler = req
             .app_data::<Self::Config>()
-            .map(|c| c.ehandler.clone())
+            .and_then(|c| c.ehandler.clone());
-            .unwrap_or(None);
 
         ready(
             de::Deserialize::deserialize(PathDeserializer::new(req.match_info()))

src/types/payload.rs

@@ -1,6 +1,7 @@
 //! Basic binary and string payload extractors.
 
 use std::{
+    borrow::Cow,
     future::Future,
     pin::Pin,
     str,
@@ -46,6 +47,7 @@ pub struct Payload(pub crate::dev::Payload);
 
 impl Payload {
     /// Unwrap to inner Payload type.
+    #[must_use]
     pub fn into_inner(self) -> crate::dev::Payload {
         self.0
     }
@@ -190,7 +192,7 @@ fn bytes_to_string(body: Bytes, encoding: &'static Encoding) -> Result<String, E
     } else {
         Ok(encoding
             .decode_without_bom_handling_and_without_replacement(&body)
-            .map(|s| s.into_owned())
+            .map(Cow::into_owned)
             .ok_or_else(|| ErrorBadRequest("Can not decode body"))?)
     }
 }
@@ -213,6 +215,7 @@ pub struct PayloadConfig {
 
 impl PayloadConfig {
     /// Create new instance with a size limit (in bytes) and no mime type condition.
+    #[must_use]
     pub fn new(limit: usize) -> Self {
         Self {
             limit,
@@ -221,12 +224,14 @@ impl PayloadConfig {
     }
 
     /// Set maximum accepted payload size in bytes. The default limit is 256kB.
+    #[must_use]
     pub fn limit(mut self, limit: usize) -> Self {
         self.limit = limit;
         self
     }
 
     /// Set required mime type of the request. By default mime type is not enforced.
+    #[must_use]
     pub fn mimetype(mut self, mt: Mime) -> Self {
         self.mimetype = Some(mt);
         self

src/types/query.rs

@@ -119,8 +119,7 @@ where
     fn from_request(req: &HttpRequest, _: &mut Payload) -> Self::Future {
         let error_handler = req
             .app_data::<Self::Config>()
-            .map(|c| c.err_handler.clone())
+            .and_then(|c| c.err_handler.clone());
-            .unwrap_or(None);
 
         serde_urlencoded::from_str::<T>(req.query_string())
             .map(|val| ok(Query(val)))

src/web.rs

@@ -52,6 +52,7 @@ pub use crate::types::*;
 ///         .route(web::head().to(|| HttpResponse::MethodNotAllowed()))
 /// );
 /// ```
+#[must_use]
 pub fn resource<T: IntoPattern>(path: T) -> Resource {
     Resource::new(path)
 }
@@ -77,11 +78,13 @@ pub fn resource<T: IntoPattern>(path: T) -> Resource {
 ///  * /{project_id}/path2
 ///  * /{project_id}/path3
 ///
+#[must_use]
 pub fn scope(path: &str) -> Scope {
     Scope::new(path)
 }
 
 /// Create *route* without configuration.
+#[must_use]
 pub fn route() -> Route {
     Route::new()
 }
@@ -100,6 +103,7 @@ pub fn route() -> Route {
 /// In the above example, one `GET` route gets added:
 ///  * /{project_id}
 ///
+#[must_use]
 pub fn get() -> Route {
     method(Method::GET)
 }
@@ -118,6 +122,7 @@ pub fn get() -> Route {
 /// In the above example, one `POST` route gets added:
 ///  * /{project_id}
 ///
+#[must_use]
 pub fn post() -> Route {
     method(Method::POST)
 }
@@ -136,6 +141,7 @@ pub fn post() -> Route {
 /// In the above example, one `PUT` route gets added:
 ///  * /{project_id}
 ///
+#[must_use]
 pub fn put() -> Route {
     method(Method::PUT)
 }
@@ -154,6 +160,7 @@ pub fn put() -> Route {
 /// In the above example, one `PATCH` route gets added:
 ///  * /{project_id}
 ///
+#[must_use]
 pub fn patch() -> Route {
     method(Method::PATCH)
 }
@@ -172,6 +179,7 @@ pub fn patch() -> Route {
 /// In the above example, one `DELETE` route gets added:
 ///  * /{project_id}
 ///
+#[must_use]
 pub fn delete() -> Route {
     method(Method::DELETE)
 }
@@ -190,6 +198,7 @@ pub fn delete() -> Route {
 /// In the above example, one `HEAD` route gets added:
 ///  * /{project_id}
 ///
+#[must_use]
 pub fn head() -> Route {
     method(Method::HEAD)
 }
@@ -208,6 +217,7 @@ pub fn head() -> Route {
 /// In the above example, one `HEAD` route gets added:
 ///  * /{project_id}
 ///
+#[must_use]
 pub fn trace() -> Route {
     method(Method::TRACE)
 }
@@ -226,6 +236,7 @@ pub fn trace() -> Route {
 /// In the above example, one `GET` route gets added:
 ///  * /{project_id}
 ///
+#[must_use]
 pub fn method(method: Method) -> Route {
     Route::new().method(method)
 }
@@ -244,6 +255,7 @@ pub fn method(method: Method) -> Route {
 ///         web::to(index))
 /// );
 /// ```
+#[must_use]
 pub fn to<F, I, R>(handler: F) -> Route
 where
     F: Handler<I, R>,
@@ -269,6 +281,7 @@ where
 ///         .finish(my_service)
 /// );
 /// ```
+#[must_use]
 pub fn service<T: IntoPattern>(path: T) -> WebService {
     WebService::new(path)
 }