clippy: Fix single_match warnings (#31876)

components/script/dom/audionode.rs

@@ -354,11 +354,10 @@ impl AudioNodeMethods for AudioNode {
             return Ok(());
         }
 
-        match self.upcast::<EventTarget>().type_id() {
-            EventTargetTypeId::AudioNode(AudioNodeTypeId::ChannelSplitterNode) => {
+        if let EventTargetTypeId::AudioNode(AudioNodeTypeId::ChannelSplitterNode) =
+            self.upcast::<EventTarget>().type_id()
+        {
             return Err(Error::InvalidState);
-            },
-            _ => (),
         };
 
         self.channel_interpretation.set(value);

components/script/dom/bindings/str.rs

@@ -741,13 +741,10 @@ fn parse_time_component(value: &str) -> Option<(u32, u32, f64)> {
             if second_iterator.next()?.len() != 2 {
                 return None;
             }
-            match second_iterator.next() {
-                Some(second_last) => {
+            if let Some(second_last) = second_iterator.next() {
                 if second_last.len() > 3 {
                     return None;
                 }
-                },
-                None => {},
             }
 
             second.parse::<f64>().ok()?

components/script/dom/htmlobjectelement.rs

@@ -74,17 +74,14 @@ impl<'a> ProcessDataURL for &'a HTMLObjectElement {
     // Makes the local `data` member match the status of the `data` attribute and starts
     /// prefetching the image. This method must be called after `data` is changed.
     fn process_data_url(&self) {
-        let elem = self.upcast::<Element>();
+        let element = self.upcast::<Element>();
 
         // TODO: support other values
-        match (
-            elem.get_attribute(&ns!(), &local_name!("type")),
-            elem.get_attribute(&ns!(), &local_name!("data")),
+        if let (None, Some(_uri)) = (
+            element.get_attribute(&ns!(), &local_name!("type")),
+            element.get_attribute(&ns!(), &local_name!("data")),
         ) {
-            (None, Some(_uri)) => {
             // TODO(gw): Prefetch the image here.
-            },
-            _ => {},
         }
     }
 }

components/script/dom/node.rs

@@ -2981,8 +2981,7 @@ impl NodeMethods for Node {
         // same owner element.
         if let Some(node2) = node2 {
             if Some(node2) == node1 {
-                match (attr1, attr2) {
-                    (Some(a1), Some(a2)) => {
+                if let (Some(a1), Some(a2)) = (attr1, attr2) {
                     let attrs = node2.downcast::<Element>().unwrap().attrs();
                     // go through the attrs in order to see if self
                     // or other is first; spec is clear that we
@@ -3006,8 +3005,6 @@ impl NodeMethods for Node {
                     // both attrs have node2 as their owner element, so
                     // we can't have left the loop without seeing them
                     unreachable!();
-                    },
-                    (_, _) => {},
                 }
             }
         }

components/script/dom/rtcdatachannel.rs

@@ -200,8 +200,7 @@ impl RTCDataChannel {
     }
 
     pub fn on_state_change(&self, state: DataChannelState) {
-        match state {
-            DataChannelState::Closing => {
+        if let DataChannelState::Closing = state {
             let event = Event::new(
                 &self.global(),
                 atom!("closing"),
@@ -209,8 +208,6 @@ impl RTCDataChannel {
                 EventCancelable::NotCancelable,
             );
             event.upcast::<Event>().fire(self.upcast());
-            },
-            _ => {},
         };
         self.ready_state.set(state.into());
     }

components/script/dom/xmlhttprequest.rs

@@ -724,8 +724,7 @@ impl XMLHttpRequestMethods for XMLHttpRequest {
         .pipeline_id(Some(self.global().pipeline_id()));
 
         // step 4 (second half)
-        match content_type {
-            Some(content_type) => {
+        if let Some(content_type) = content_type {
             let encoding = match data {
                 Some(DocumentOrXMLHttpRequestBodyInit::String(_)) |
                 Some(DocumentOrXMLHttpRequestBodyInit::Document(_)) =>
@@ -781,8 +780,6 @@ impl XMLHttpRequestMethods for XMLHttpRequest {
                     }
                 }
             }
-            },
-            _ => (),
         }
 
         self.fetch_time.set(time::now().to_timespec().sec);

components/script/script_thread.rs

@@ -2778,11 +2778,11 @@ impl ScriptThread {
             Some(idx) => {
                 // https://html.spec.whatwg.org/multipage/#process-a-navigate-response
                 // 2. If response's status is 204 or 205, then abort these steps.
-                match metadata {
-                    Some(Metadata {
+                if let Some(Metadata {
                     status: Some((204..=205, _)),
                     ..
-                    }) => {
+                }) = metadata
+                {
                     // If we have an existing window that is being navigated:
                     if let Some(window) = self.documents.borrow().find_window(*id) {
                         let window_proxy = window.window_proxy();
@@ -2801,8 +2801,6 @@ impl ScriptThread {
                         .send((*id, ScriptMsg::AbortLoadUrl))
                         .unwrap();
                     return None;
-                    },
-                    _ => (),
                 };
 
                 let load = self.incomplete_loads.borrow_mut().remove(idx);