clippy: Fix unnecessary_cast warnings in components/script (#31823)

* clippy: Fix unnecessary cast warnings

* clippy: Replace redundant field names with their shorthand alternatives

* clippy: Delete struct pattern dereferencings

components/script/canvas_state.rs

@@ -607,7 +607,7 @@ impl CanvasState {
     ) -> (Rect<f64>, Rect<f64>) {
         let image_rect = Rect::new(
             Point2D::new(0f64, 0f64),
-            Size2D::new(image_size.width as f64, image_size.height as f64),
+            Size2D::new(image_size.width, image_size.height),
         );
 
         // The source rectangle is the rectangle whose corners are the four points (sx, sy),

components/script/dom/bindings/buffer_source.rs

@@ -422,14 +422,13 @@ where
     }
 
     unsafe {
-        let mapping_slice_ptr =
-            mapping.lock().unwrap().borrow_mut()[offset as usize..m_end as usize].as_mut_ptr();
+        let mapping_slice_ptr = mapping.lock().unwrap().borrow_mut()[offset..m_end].as_mut_ptr();
 
         // rooted! is needed to ensure memory safety and prevent potential garbage collection issues.
         // https://github.com/mozilla-spidermonkey/spidermonkey-embedding-examples/blob/esr78/docs/GC%20Rooting%20Guide.md#performance-tweaking
         rooted!(in(*cx) let array_buffer = NewExternalArrayBuffer(
             *cx,
-            range_size as usize,
+            range_size,
             mapping_slice_ptr as _,
             Some(free_func),
             Arc::into_raw(mapping) as _,

components/script/dom/bindings/conversions.rs

@@ -228,8 +228,8 @@ pub unsafe fn jsstring_to_str(cx: *mut JSContext, s: *mut JSString) -> DOMString
         let mut length = 0;
         let chars = JS_GetTwoByteStringCharsAndLength(cx, ptr::null(), s, &mut length);
         assert!(!chars.is_null());
-        let potentially_ill_formed_utf16 = slice::from_raw_parts(chars, length as usize);
-        let mut s = String::with_capacity(length as usize);
+        let potentially_ill_formed_utf16 = slice::from_raw_parts(chars, length);
+        let mut s = String::with_capacity(length);
         for item in char::decode_utf16(potentially_ill_formed_utf16.iter().cloned()) {
             match item {
                 Ok(c) => s.push(c),
@@ -282,7 +282,7 @@ impl FromJSValConvertible for USVString {
         let mut length = 0;
         let chars = JS_GetTwoByteStringCharsAndLength(cx, ptr::null(), jsstr, &mut length);
         assert!(!chars.is_null());
-        let char_vec = slice::from_raw_parts(chars as *const u16, length as usize);
+        let char_vec = slice::from_raw_parts(chars as *const u16, length);
         Ok(ConversionResult::Success(USVString(
             String::from_utf16_lossy(char_vec),
         )))
@@ -324,7 +324,7 @@ impl FromJSValConvertible for ByteString {
             let chars = JS_GetLatin1StringCharsAndLength(cx, ptr::null(), string, &mut length);
             assert!(!chars.is_null());
 
-            let char_slice = slice::from_raw_parts(chars as *mut u8, length as usize);
+            let char_slice = slice::from_raw_parts(chars as *mut u8, length);
             return Ok(ConversionResult::Success(ByteString::new(
                 char_slice.to_vec(),
             )));
@@ -332,7 +332,7 @@ impl FromJSValConvertible for ByteString {
 
         let mut length = 0;
         let chars = JS_GetTwoByteStringCharsAndLength(cx, ptr::null(), string, &mut length);
-        let char_vec = slice::from_raw_parts(chars, length as usize);
+        let char_vec = slice::from_raw_parts(chars, length);
 
         if char_vec.iter().any(|&c| c > 0xFF) {
             throw_type_error(cx, "Invalid ByteString");

components/script/dom/bindings/str.rs

@@ -776,7 +776,7 @@ fn max_day_in_month(year_num: i32, month_num: u32) -> Option<u32> {
 
 /// <https://html.spec.whatwg.org/multipage/#week-number-of-the-last-day>
 fn max_week_in_year(year: i32) -> u32 {
-    Utc.with_ymd_and_hms(year as i32, 1, 1, 0, 0, 0)
+    Utc.with_ymd_and_hms(year, 1, 1, 0, 0, 0)
         .earliest()
         .map(|date_time| match date_time.weekday() {
             Weekday::Thu => 53,

components/script/dom/bindings/utils.rs

@@ -451,7 +451,7 @@ pub unsafe extern "C" fn resolve_global(
     let mut length = 0;
     let ptr = JS_GetLatin1StringCharsAndLength(cx, ptr::null(), string, &mut length);
     assert!(!ptr.is_null());
-    let bytes = slice::from_raw_parts(ptr, length as usize);
+    let bytes = slice::from_raw_parts(ptr, length);
 
     if let Some(init_fun) = InterfaceObjectMap::MAP.get(bytes) {
         init_fun(SafeJSContext::from_ptr(cx), Handle::from_raw(obj));

components/script/dom/canvasgradient.rs

@@ -59,7 +59,7 @@ impl CanvasGradientMethods for CanvasGradient {
         };
 
         self.stops.borrow_mut().push(CanvasGradientStop {
-            offset: (*offset) as f64,
+            offset: (*offset),
             color,
         });
         Ok(())

components/script/dom/globalscope.rs

@@ -2001,7 +2001,7 @@ impl GlobalScope {
 
         let stream = ReadableStream::new_with_external_underlying_source(
             self,
-            ExternalUnderlyingSource::Blob(size as usize),
+            ExternalUnderlyingSource::Blob(size),
         );
 
         let recv = self.send_msg(file_id);
@@ -3171,7 +3171,7 @@ impl GlobalScope {
                             }
                         }
                         for i in (0..gamepad_list.Length()).rev() {
-                            if gamepad_list.Item(i as u32).is_none() {
+                            if gamepad_list.Item(i).is_none() {
                                 gamepad_list.remove_gamepad(i as usize);
                             } else {
                                 break;
@@ -3211,7 +3211,7 @@ impl GlobalScope {
                             if !window.Navigator().has_gamepad_gesture() && contains_user_gesture(update_type) {
                                 window.Navigator().set_has_gamepad_gesture(true);
                                 for i in 0..gamepad_list.Length() {
-                                    if let Some(gamepad) = gamepad_list.Item(i as u32) {
+                                    if let Some(gamepad) = gamepad_list.Item(i) {
                                         gamepad.set_exposed(true);
                                         gamepad.update_timestamp(*current_time);
                                         let new_gamepad = Trusted::new(&*gamepad);

components/script/dom/htmlareaelement.rs

@@ -222,8 +222,8 @@ impl Area {
                     .iter()
                     .enumerate()
                     .map(|(index, point)| match index % 2 {
-                        0 => point + p.x as f32,
-                        _ => point + p.y as f32,
+                        0 => point + p.x,
+                        _ => point + p.y,
                     });
                 Area::Polygon {
                     points: iter.collect::<Vec<_>>(),

components/script/dom/htmlformelement.rs

@@ -393,7 +393,7 @@ impl HTMLFormElementMethods for HTMLFormElement {
 
     // https://html.spec.whatwg.org/multipage/#dom-form-length
     fn Length(&self) -> u32 {
-        self.Elements().Length() as u32
+        self.Elements().Length()
     }
 
     // https://html.spec.whatwg.org/multipage/#dom-form-item

components/script/dom/htmlinputelement.rs

@@ -2155,7 +2155,7 @@ impl HTMLInputElement {
                 .map(|time| time.and_utc().timestamp_millis() as f64),
             InputType::Time => match value.parse_time_string() {
                 Some((hours, minutes, seconds)) => {
-                    Some((seconds as f64 + 60.0 * minutes as f64 + 3600.0 * hours as f64) * 1000.0)
+                    Some((seconds + 60.0 * minutes as f64 + 3600.0 * hours as f64) * 1000.0)
                 },
                 _ => None,
             },
@@ -2543,7 +2543,7 @@ impl VirtualMethods for HTMLInputElement {
                         let TextIndexResponse(index) =
                             window.text_index_query(self.upcast::<Node>(), point_in_target);
                         if let Some(i) = index {
-                            self.textinput.borrow_mut().set_edit_point_index(i as usize);
+                            self.textinput.borrow_mut().set_edit_point_index(i);
                             // trigger redraw
                             self.upcast::<Node>().dirty(NodeDamage::OtherNodeDamage);
                             event.PreventDefault();

components/script/dom/htmlmediaelement.rs

@@ -2334,7 +2334,7 @@ impl HTMLMediaElementMethods for HTMLMediaElement {
         if let Some(ref player) = *self.player.borrow() {
             if let Ok(ranges) = player.lock().unwrap().buffered() {
                 for range in ranges {
-                    let _ = buffered.add(range.start as f64, range.end as f64);
+                    let _ = buffered.add(range.start, range.end);
                 }
             }
         }
@@ -2504,7 +2504,7 @@ impl MicrotaskRunnable for MediaElementMicrotask {
                     elem.resource_selection_algorithm_sync(base_url.clone());
                 }
             },
-            &MediaElementMicrotask::PauseIfNotInDocumentTask { ref elem } => {
+            MediaElementMicrotask::PauseIfNotInDocumentTask { elem } => {
                 if !elem.upcast::<Node>().is_connected() {
                     elem.internal_pause_steps();
                 }

components/script/dom/node.rs

@@ -2803,7 +2803,7 @@ impl NodeMethods for Node {
                         .ranges
                         .drain_to_preceding_text_sibling(&sibling, &node, length);
                     self.ranges
-                        .move_to_text_child_at(self, index as u32, &node, length as u32);
+                        .move_to_text_child_at(self, index as u32, &node, length);
                     let sibling_cdata = sibling.downcast::<CharacterData>().unwrap();
                     length += sibling_cdata.Length();
                     cdata.append_data(&sibling_cdata.data());

components/script/dom/nodelist.rs

@@ -172,7 +172,7 @@ impl ChildrenList {
     pub fn item(&self, index: u32) -> Option<DomRoot<Node>> {
         // This always start traversing the children from the closest element
         // among parent's first and last children and the last visited one.
-        let len = self.len() as u32;
+        let len = self.len();
         if index >= len {
             return None;
         }

components/script/dom/paintworkletglobalscope.rs

@@ -379,8 +379,8 @@ impl PaintWorkletGlobalScope {
     ) -> DrawAPaintImageResult {
         debug!("Returning an invalid image.");
         DrawAPaintImageResult {
-            width: size.width as u32,
-            height: size.height as u32,
+            width: size.width,
+            height: size.height,
             format: PixelFormat::BGRA8,
             image_key: None,
             missing_image_urls,

components/script/dom/readablestream.rs

@@ -497,7 +497,7 @@ impl ExternalUnderlyingSourceController {
     fn get_chunk_with_length(&self, length: usize) -> Vec<u8> {
         let mut buffer = self.buffer.borrow_mut();
         let buffer_len = buffer.len();
-        assert!(buffer_len >= length as usize);
+        assert!(buffer_len >= length);
         buffer.split_off(buffer_len - length)
     }
 

components/script/dom/texttracklist.rs

@@ -40,7 +40,7 @@ impl TextTrackList {
     pub fn item(&self, idx: usize) -> Option<DomRoot<TextTrack>> {
         self.dom_tracks
             .borrow()
-            .get(idx as usize)
+            .get(idx)
             .map(|t| DomRoot::from_ref(&**t))
     }
 

components/script/dom/webgl_validations/tex_image_2d.rs

@@ -765,7 +765,7 @@ impl<'a> WebGLValidator for TexStorageValidator<'a> {
             return Err(TexImageValidationError::InvalidTextureFormat);
         }
 
-        let max_level = log2(cmp::max(width, height) as u32) + 1;
+        let max_level = log2(cmp::max(width, height)) + 1;
         if level > max_level {
             context.webgl_error(InvalidOperation);
             return Err(TexImageValidationError::LevelTooHigh);

components/script/dom/webglrenderingcontext.rs

@@ -2664,15 +2664,7 @@ impl WebGLRenderingContextMethods for WebGLRenderingContext {
         // NB: TexImage2D depth is always equal to 1
         handle_potential_webgl_error!(
             self,
-            texture.initialize(
-                target,
-                width as u32,
-                height as u32,
-                1,
-                internal_format,
-                level as u32,
-                None
-            )
+            texture.initialize(target, width, height, 1, internal_format, level, None)
         );
 
         let msg = WebGLCommand::CopyTexImage2D(

components/script/layout_dom/node.rs

@@ -285,7 +285,7 @@ impl<'dom, LayoutDataType: LayoutDataTrait> ServoThreadSafeLayoutNode<'dom, Layo
     /// Creates a new `ServoThreadSafeLayoutNode` from the given `ServoLayoutNode`.
     pub fn new(node: ServoLayoutNode<'dom, LayoutDataType>) -> Self {
         ServoThreadSafeLayoutNode {
-            node: node,
+            node,
             pseudo: PseudoElementType::Normal,
         }
     }

components/script/script_module.rs

@@ -1658,7 +1658,7 @@ fn fetch_single_module_script(
         data: vec![],
         metadata: None,
         url: url.clone(),
-        destination: destination,
+        destination,
         options,
         status: Ok(()),
         resource_timing: ResourceFetchTiming::new(ResourceTimingType::Resource),

components/script/script_runtime.rs

@@ -700,11 +700,7 @@ pub fn get_reports(cx: *mut RawJSContext, path_seg: String) -> Vec<Report> {
             let mut report = |mut path_suffix, kind, size| {
                 let mut path = path![path_seg, "js"];
                 path.append(&mut path_suffix);
-                reports.push(Report {
-                    path,
-                    kind,
-                    size: size as usize,
-                })
+                reports.push(Report { path, kind, size })
             };
 
             // A note about possibly confusing terminology: the JS GC "heap" is allocated via