diff --git a/src/wp-includes/rest-api/class-wp-rest-request.php b/src/wp-includes/rest-api/class-wp-rest-request.php
index 6ed6ce667432c..ffae8d251bc9a 100644
--- a/src/wp-includes/rest-api/class-wp-rest-request.php
+++ b/src/wp-includes/rest-api/class-wp-rest-request.php
@@ -199,7 +199,7 @@ public static function canonicalize_header_name( $key ) {
 	 * @return string|null String value if set, null otherwise.
 	 */
 	public function get_header( $key ) {
-		$key = $this->canonicalize_header_name( $key );
+		$key = static::canonicalize_header_name( $key );
 
 		if ( ! isset( $this->headers[ $key ] ) ) {
 			return null;
@@ -217,7 +217,7 @@ public function get_header( $key ) {
 	 * @return array|null List of string values if set, null otherwise.
 	 */
 	public function get_header_as_array( $key ) {
-		$key = $this->canonicalize_header_name( $key );
+		$key = static::canonicalize_header_name( $key );
 
 		if ( ! isset( $this->headers[ $key ] ) ) {
 			return null;
@@ -235,7 +235,7 @@ public function get_header_as_array( $key ) {
 	 * @param string $value Header value, or list of values.
 	 */
 	public function set_header( $key, $value ) {
-		$key   = $this->canonicalize_header_name( $key );
+		$key   = static::canonicalize_header_name( $key );
 		$value = (array) $value;
 
 		$this->headers[ $key ] = $value;
@@ -250,7 +250,7 @@ public function set_header( $key, $value ) {
 	 * @param string $value Header value, or list of values.
 	 */
 	public function add_header( $key, $value ) {
-		$key   = $this->canonicalize_header_name( $key );
+		$key   = static::canonicalize_header_name( $key );
 		$value = (array) $value;
 
 		if ( ! isset( $this->headers[ $key ] ) ) {
@@ -268,7 +268,7 @@ public function add_header( $key, $value ) {
 	 * @param string $key Header name.
 	 */
 	public function remove_header( $key ) {
-		$key = $this->canonicalize_header_name( $key );
+		$key = static::canonicalize_header_name( $key );
 		unset( $this->headers[ $key ] );
 	}
 
diff --git a/src/wp-includes/rest-api/class-wp-rest-response.php b/src/wp-includes/rest-api/class-wp-rest-response.php
index c6ea11be83ee3..a5e4b9533d165 100644
--- a/src/wp-includes/rest-api/class-wp-rest-response.php
+++ b/src/wp-includes/rest-api/class-wp-rest-response.php
@@ -85,11 +85,9 @@ public function remove_link( $rel, $href = null ) {
 			return;
 		}
 
-		if ( $href ) {
-			$this->links[ $rel ] = wp_list_filter( $this->links[ $rel ], array( 'href' => $href ), 'NOT' );
-		} else {
-			$this->links[ $rel ] = array();
-		}
+		$this->links[ $rel ] = $href
+			? wp_list_filter( $this->links[ $rel ], array( 'href' => $href ), 'NOT' )
+			: array();
 
 		if ( ! $this->links[ $rel ] ) {
 			unset( $this->links[ $rel ] );
diff --git a/src/wp-includes/rest-api/class-wp-rest-server.php b/src/wp-includes/rest-api/class-wp-rest-server.php
index 17d620f6fb6e0..a38da2f532e10 100644
--- a/src/wp-includes/rest-api/class-wp-rest-server.php
+++ b/src/wp-includes/rest-api/class-wp-rest-server.php
@@ -364,11 +364,7 @@ public function serve_request( $path = null ) {
 		}
 
 		if ( empty( $path ) ) {
-			if ( isset( $_SERVER['PATH_INFO'] ) ) {
-				$path = $_SERVER['PATH_INFO'];
-			} else {
-				$path = '/';
-			}
+			$path = isset( $_SERVER['PATH_INFO'] ) ? $_SERVER['PATH_INFO'] : '/';
 		}
 
 		$request = new WP_REST_Request( $_SERVER['REQUEST_METHOD'], $path );
@@ -738,7 +734,7 @@ public static function get_compact_response_links( $response ) {
 				// Relation now changes from '$uri' to '$curie:$relation'.
 				$rel_regex = str_replace( '\{rel\}', '(.+)', preg_quote( $curie['href'], '!' ) );
 				preg_match( '!' . $rel_regex . '!', $rel, $matches );
-				if ( $matches ) {
+				if ( array() !== $matches ) {
 					$new_rel                       = $curie['name'] . ':' . $matches[1];
 					$used_curies[ $curie['name'] ] = $curie;
 					$links[ $new_rel ]             = $items;
@@ -749,7 +745,7 @@ public static function get_compact_response_links( $response ) {
 		}
 
 		// Push the curies onto the start of the links array.
-		if ( $used_curies ) {
+		if ( array() !== $used_curies ) {
 			$links['curies'] = array_values( $used_curies );
 		}
 
@@ -836,7 +832,7 @@ protected function embed_links( $data, $embed = true ) {
 			}
 		}
 
-		if ( ! empty( $embedded ) ) {
+		if ( array() !== $embedded ) {
 			$data['_embedded'] = $embedded;
 		}
 
@@ -1161,16 +1157,14 @@ protected function match_request_to_handler( $request ) {
 			}
 		}
 
-		if ( $with_namespace ) {
-			$routes = array_merge( ...$with_namespace );
-		} else {
-			$routes = $this->get_routes();
-		}
+		$routes = array() !== $with_namespace
+			? array_merge( ...$with_namespace )
+			: $this->get_routes();
 
 		foreach ( $routes as $route => $handlers ) {
 			$match = preg_match( '@^' . $route . '$@i', $path, $matches );
 
-			if ( ! $match ) {
+			if ( 1 !== $match ) {
 				continue;
 			}
 
@@ -1255,7 +1249,7 @@ protected function respond_to_request( $request, $route, $handler, $response ) {
 		$response = apply_filters( 'rest_request_before_callbacks', $response, $handler, $request );
 
 		// Check permission specified on the route.
-		if ( ! is_wp_error( $response ) && ! empty( $handler['permission_callback'] ) ) {
+		if ( ! empty( $handler['permission_callback'] ) && ! is_wp_error( $response ) ) {
 			$permission = call_user_func( $handler['permission_callback'], $request );
 
 			if ( is_wp_error( $permission ) ) {
@@ -1286,11 +1280,9 @@ protected function respond_to_request( $request, $route, $handler, $response ) {
 			$dispatch_result = apply_filters( 'rest_dispatch_request', null, $request, $route, $handler );
 
 			// Allow plugins to halt the request via this filter.
-			if ( null !== $dispatch_result ) {
-				$response = $dispatch_result;
-			} else {
-				$response = call_user_func( $handler['callback'], $request );
-			}
+			$response = null === $dispatch_result
+				? call_user_func( $handler['callback'], $request )
+				: $dispatch_result;
 		}
 
 		/**
@@ -1316,11 +1308,9 @@ protected function respond_to_request( $request, $route, $handler, $response ) {
 		 */
 		$response = apply_filters( 'rest_request_after_callbacks', $response, $handler, $request );
 
-		if ( is_wp_error( $response ) ) {
-			$response = $this->error_to_response( $response );
-		} else {
-			$response = rest_ensure_response( $response );
-		}
+		$response = is_wp_error( $response )
+			? $this->error_to_response( $response )
+			: rest_ensure_response( $response );
 
 		$response->set_matched_route( $route );
 		$response->set_matched_handler( $handler );
diff --git a/src/wp-includes/rest-api/endpoints/class-wp-rest-attachments-controller.php b/src/wp-includes/rest-api/endpoints/class-wp-rest-attachments-controller.php
index 0c98a729e43f9..4c6e72705b0f0 100644
--- a/src/wp-includes/rest-api/endpoints/class-wp-rest-attachments-controller.php
+++ b/src/wp-includes/rest-api/endpoints/class-wp-rest-attachments-controller.php
@@ -443,9 +443,8 @@ public function update_item( $request ) {
 		wp_after_insert_post( $attachment, true, $attachment_before );
 
 		$response = $this->prepare_item_for_response( $attachment, $request );
-		$response = rest_ensure_response( $response );
 
-		return $response;
+		return rest_ensure_response( $response );
 	}
 
 	/**
@@ -457,11 +456,9 @@ public function update_item( $request ) {
 	 * @return WP_REST_Response|WP_Error Response object on success, WP_Error object on failure.
 	 */
 	public function post_process_item( $request ) {
-		switch ( $request['action'] ) {
-			case 'create-image-subsizes':
-				require_once ABSPATH . 'wp-admin/includes/image.php';
-				wp_update_image_subsizes( $request['id'] );
-				break;
+		if ( 'create-image-subsizes' === $request['action'] ) {
+			require_once ABSPATH . 'wp-admin/includes/image.php';
+			wp_update_image_subsizes( $request['id'] );
 		}
 
 		$request['context'] = 'edit';
@@ -567,7 +564,7 @@ public function edit_media_item( $request ) {
 				);
 			}
 
-			if ( 0 === count( $modifiers ) ) {
+			if ( array() === $modifiers ) {
 				return new WP_Error(
 					'rest_image_not_edited',
 					__( 'The image was not edited. Edit the image before applying the changes.' ),
@@ -722,7 +719,7 @@ public function edit_media_item( $request ) {
 		$new_image_meta = wp_generate_attachment_metadata( $new_attachment_id, $saved['path'] );
 
 		// Copy the EXIF metadata from the original attachment if not generated for the edited image.
-		if ( isset( $image_meta['image_meta'] ) && isset( $new_image_meta['image_meta'] ) && is_array( $new_image_meta['image_meta'] ) ) {
+		if ( isset( $image_meta['image_meta'], $new_image_meta['image_meta'] ) && is_array( $new_image_meta['image_meta'] ) ) {
 			// Merge but skip empty values.
 			foreach ( (array) $image_meta['image_meta'] as $key => $value ) {
 				if ( empty( $new_image_meta['image_meta'][ $key ] ) && ! empty( $value ) ) {
@@ -1142,7 +1139,7 @@ protected function upload_from_data( $data, $headers, $time = null ) {
 			'type'     => $type,
 		);
 
-		$size_check = self::check_upload_size( $file_data );
+		$size_check = $this->check_upload_size( $file_data );
 		if ( is_wp_error( $size_check ) ) {
 			return $size_check;
 		}
@@ -1310,7 +1307,7 @@ protected function upload_from_file( $files, $headers, $time = null ) {
 			$overrides['action'] = 'wp_handle_mock_upload';
 		}
 
-		$size_check = self::check_upload_size( $files['file'] );
+		$size_check = $this->check_upload_size( $files['file'] );
 		if ( is_wp_error( $size_check ) ) {
 			return $size_check;
 		}
diff --git a/src/wp-includes/rest-api/endpoints/class-wp-rest-autosaves-controller.php b/src/wp-includes/rest-api/endpoints/class-wp-rest-autosaves-controller.php
index 5545625df4609..ab615f1ff0600 100644
--- a/src/wp-includes/rest-api/endpoints/class-wp-rest-autosaves-controller.php
+++ b/src/wp-includes/rest-api/endpoints/class-wp-rest-autosaves-controller.php
@@ -285,8 +285,7 @@ public function get_item( $request ) {
 			);
 		}
 
-		$response = $this->prepare_item_for_response( $autosave, $request );
-		return $response;
+		return $this->prepare_item_for_response( $autosave, $request );
 	}
 
 	/**
@@ -418,7 +417,7 @@ public function create_post_autosave( $post_data, array $meta = array() ) {
 			$revision_id = _wp_put_post_revision( $post_data, true );
 		}
 
-		if ( is_wp_error( $revision_id ) || 0 === $revision_id ) {
+		if ( 0 === $revision_id || is_wp_error( $revision_id ) ) {
 			return $revision_id;
 		}
 
diff --git a/src/wp-includes/rest-api/endpoints/class-wp-rest-block-renderer-controller.php b/src/wp-includes/rest-api/endpoints/class-wp-rest-block-renderer-controller.php
index 3e4e8eb794d37..685b33902f9cc 100644
--- a/src/wp-includes/rest-api/endpoints/class-wp-rest-block-renderer-controller.php
+++ b/src/wp-includes/rest-api/endpoints/class-wp-rest-block-renderer-controller.php
@@ -125,16 +125,14 @@ public function get_item_permissions_check( $request ) {
 					)
 				);
 			}
-		} else {
-			if ( ! current_user_can( 'edit_posts' ) ) {
-				return new WP_Error(
-					'block_cannot_read',
-					__( 'Sorry, you are not allowed to read blocks as this user.' ),
-					array(
-						'status' => rest_authorization_required_code(),
-					)
-				);
-			}
+		} elseif ( ! current_user_can( 'edit_posts' ) ) {
+			return new WP_Error(
+				'block_cannot_read',
+				__( 'Sorry, you are not allowed to read blocks as this user.' ),
+				array(
+					'status' => rest_authorization_required_code(),
+				)
+			);
 		}
 
 		return true;
diff --git a/src/wp-includes/rest-api/endpoints/class-wp-rest-block-types-controller.php b/src/wp-includes/rest-api/endpoints/class-wp-rest-block-types-controller.php
index 263f2a8ef2066..53f853ad0fb2c 100644
--- a/src/wp-includes/rest-api/endpoints/class-wp-rest-block-types-controller.php
+++ b/src/wp-includes/rest-api/endpoints/class-wp-rest-block-types-controller.php
@@ -305,7 +305,7 @@ public function prepare_item_for_response( $item, $request ) {
 			if ( rest_is_field_included( $extra_field, $fields ) ) {
 				if ( isset( $block_type->$extra_field ) ) {
 					$field = $block_type->$extra_field;
-					if ( in_array( $extra_field, $deprecated_fields, true ) && is_array( $field ) ) {
+					if ( is_array( $field ) && in_array( $extra_field, $deprecated_fields, true ) ) {
 						// Since the schema only allows strings or null (but no arrays), we return the first array item.
 						$field = ! empty( $field ) ? array_shift( $field ) : '';
 					}
diff --git a/src/wp-includes/rest-api/endpoints/class-wp-rest-blocks-controller.php b/src/wp-includes/rest-api/endpoints/class-wp-rest-blocks-controller.php
index 6f600a04945f0..21c78a7fbd82d 100644
--- a/src/wp-includes/rest-api/endpoints/class-wp-rest-blocks-controller.php
+++ b/src/wp-includes/rest-api/endpoints/class-wp-rest-blocks-controller.php
@@ -54,8 +54,7 @@ public function filter_response_by_context( $data, $context ) {
 		 * It doesn't make sense for a pattern to have rendered content on its own,
 		 * since rendering a block requires it to be inside a post or a page.
 		 */
-		unset( $data['title']['rendered'] );
-		unset( $data['content']['rendered'] );
+		unset( $data['title']['rendered'], $data['content']['rendered'] );
 
 		// Add the core wp_pattern_sync_status meta as top level property to the response.
 		$data['wp_pattern_sync_status'] = isset( $data['meta']['wp_pattern_sync_status'] ) ? $data['meta']['wp_pattern_sync_status'] : '';
diff --git a/src/wp-includes/rest-api/endpoints/class-wp-rest-comments-controller.php b/src/wp-includes/rest-api/endpoints/class-wp-rest-comments-controller.php
index c129ef6e130c4..a915167a16011 100644
--- a/src/wp-includes/rest-api/endpoints/class-wp-rest-comments-controller.php
+++ b/src/wp-includes/rest-api/endpoints/class-wp-rest-comments-controller.php
@@ -134,7 +134,9 @@ public function get_items_permissions_check( $request ) {
 						__( 'Sorry, you are not allowed to read the post for this comment.' ),
 						array( 'status' => rest_authorization_required_code() )
 					);
-				} elseif ( 0 === $post_id && ! current_user_can( 'moderate_comments' ) ) {
+				}
+
+				if ( 0 === $post_id && ! current_user_can( 'moderate_comments' ) ) {
 					return new WP_Error(
 						'rest_cannot_read',
 						__( 'Sorry, you are not allowed to read comments without a post.' ),
@@ -427,10 +429,9 @@ public function get_item( $request ) {
 			return $comment;
 		}
 
-		$data     = $this->prepare_item_for_response( $comment, $request );
-		$response = rest_ensure_response( $data );
+		$data = $this->prepare_item_for_response( $comment, $request );
 
-		return $response;
+		return rest_ensure_response( $data );
 	}
 
 	/**
@@ -484,15 +485,16 @@ public function create_item_permissions_check( $request ) {
 			);
 		}
 
-		if ( isset( $request['author_ip'] ) && ! current_user_can( 'moderate_comments' ) ) {
-			if ( empty( $_SERVER['REMOTE_ADDR'] ) || $request['author_ip'] !== $_SERVER['REMOTE_ADDR'] ) {
-				return new WP_Error(
-					'rest_comment_invalid_author_ip',
-					/* translators: %s: Request parameter. */
-					sprintf( __( "Sorry, you are not allowed to edit '%s' for comments." ), 'author_ip' ),
-					array( 'status' => rest_authorization_required_code() )
-				);
-			}
+		if ( isset( $request['author_ip'] )
+			&& ! current_user_can( 'moderate_comments' )
+			&& ( empty( $_SERVER['REMOTE_ADDR'] ) || $request['author_ip'] !== $_SERVER['REMOTE_ADDR'] )
+		) {
+			return new WP_Error(
+				'rest_comment_invalid_author_ip',
+				/* translators: %s: Request parameter. */
+				sprintf( __( "Sorry, you are not allowed to edit '%s' for comments." ), 'author_ip' ),
+				array( 'status' => rest_authorization_required_code() )
+			);
 		}
 
 		if ( isset( $request['status'] ) && ! current_user_can( 'moderate_comments' ) ) {
@@ -613,7 +615,7 @@ public function create_item( $request ) {
 			&& empty( $prepared_comment['comment_author_email'] )
 			&& empty( $prepared_comment['comment_author_url'] );
 
-		if ( is_user_logged_in() && $missing_author ) {
+		if ( $missing_author && is_user_logged_in() ) {
 			$user = wp_get_current_user();
 
 			$prepared_comment['user_id']              = $user->ID;
@@ -623,14 +625,14 @@ public function create_item( $request ) {
 		}
 
 		// Honor the discussion setting that requires a name and email address of the comment author.
-		if ( get_option( 'require_name_email' ) ) {
-			if ( empty( $prepared_comment['comment_author'] ) || empty( $prepared_comment['comment_author_email'] ) ) {
-				return new WP_Error(
-					'rest_comment_author_data_required',
-					__( 'Creating a comment requires valid author name and email values.' ),
-					array( 'status' => 400 )
-				);
-			}
+		if ( get_option( 'require_name_email' )
+			&& ( empty( $prepared_comment['comment_author'] ) || empty( $prepared_comment['comment_author_email'] ) )
+		) {
+			return new WP_Error(
+				'rest_comment_author_data_required',
+				__( 'Creating a comment requires valid author name and email values.' ),
+				array( 'status' => 400 )
+			);
 		}
 
 		if ( ! isset( $prepared_comment['comment_author_email'] ) ) {
@@ -955,7 +957,7 @@ public function delete_item( $request ) {
 			return $comment;
 		}
 
-		$force = isset( $request['force'] ) ? (bool) $request['force'] : false;
+		$force = isset( $request['force'] ) && $request['force'];
 
 		/**
 		 * Filters whether a comment can be trashed via the REST API.
@@ -1807,10 +1809,8 @@ protected function check_read_post_permission( $post, $request ) {
 	protected function check_read_permission( $comment, $request ) {
 		if ( ! empty( $comment->comment_post_ID ) ) {
 			$post = get_post( $comment->comment_post_ID );
-			if ( $post ) {
-				if ( $this->check_read_post_permission( $post, $request ) && 1 === (int) $comment->comment_approved ) {
-					return true;
-				}
+			if ( $post && ( 1 === (int) $comment->comment_approved ) && $this->check_read_post_permission( $post, $request ) ) {
+				return true;
 			}
 		}
 
diff --git a/src/wp-includes/rest-api/endpoints/class-wp-rest-font-faces-controller.php b/src/wp-includes/rest-api/endpoints/class-wp-rest-font-faces-controller.php
index ec59baa5d6c8f..038388b0cd256 100644
--- a/src/wp-includes/rest-api/endpoints/class-wp-rest-font-faces-controller.php
+++ b/src/wp-includes/rest-api/endpoints/class-wp-rest-font-faces-controller.php
@@ -249,9 +249,9 @@ public function sanitize_font_face_settings( $value ) {
 		$schema   = $this->get_item_schema()['properties']['font_face_settings']['properties'];
 
 		// Sanitize settings based on callbacks in the schema.
-		foreach ( $settings as $key => $value ) {
-			$sanitize_callback = $schema[ $key ]['arg_options']['sanitize_callback'];
-			$settings[ $key ]  = call_user_func( $sanitize_callback, $value );
+		foreach ( $settings as $setting_key => $setting_value ) {
+			$sanitize_callback        = $schema[ $setting_key ]['arg_options']['sanitize_callback'];
+			$settings[ $setting_key ] = call_user_func( $sanitize_callback, $setting_value );
 		}
 
 		return $settings;
@@ -417,7 +417,7 @@ public function delete_item( $request ) {
 			);
 		}
 
-		$force = isset( $request['force'] ) ? (bool) $request['force'] : false;
+		$force = isset( $request['force'] ) && $request['force'];
 
 		// We don't support trashing for font faces.
 		if ( ! $force ) {
diff --git a/src/wp-includes/rest-api/endpoints/class-wp-rest-font-families-controller.php b/src/wp-includes/rest-api/endpoints/class-wp-rest-font-families-controller.php
index c2d70d0dd6916..304770d3a8684 100644
--- a/src/wp-includes/rest-api/endpoints/class-wp-rest-font-families-controller.php
+++ b/src/wp-includes/rest-api/endpoints/class-wp-rest-font-families-controller.php
@@ -110,7 +110,7 @@ public function validate_font_family_settings( $value, $request ) {
 			if ( isset( $settings['slug'] ) ) {
 				return new WP_Error(
 					'rest_invalid_param',
-					/* translators: %s: Name of parameter being updated: font_family_settings[slug]". */
+					/* translators: %s: Name of parameter being updated: "font_family_settings[slug]". */
 					sprintf( __( '%s cannot be updated.' ), 'font_family_settings[slug]' ),
 					array( 'status' => 400 )
 				);
@@ -154,9 +154,9 @@ public function sanitize_font_family_settings( $value ) {
 		$schema   = $this->get_item_schema()['properties']['font_family_settings']['properties'];
 
 		// Sanitize settings based on callbacks in the schema.
-		foreach ( $settings as $key => $value ) {
-			$sanitize_callback = $schema[ $key ]['arg_options']['sanitize_callback'];
-			$settings[ $key ]  = call_user_func( $sanitize_callback, $value );
+		foreach ( $settings as $setting_key => $setting_value ) {
+			$sanitize_callback        = $schema[ $setting_key ]['arg_options']['sanitize_callback'];
+			$settings[ $setting_key ] = call_user_func( $sanitize_callback, $setting_value );
 		}
 
 		return $settings;
@@ -204,7 +204,7 @@ public function create_item( $request ) {
 	 * @return WP_REST_Response|WP_Error Response object on success, or WP_Error object on failure.
 	 */
 	public function delete_item( $request ) {
-		$force = isset( $request['force'] ) ? (bool) $request['force'] : false;
+		$force = isset( $request['force'] ) && $request['force'];
 
 		// We don't support trashing for font families.
 		if ( ! $force ) {
@@ -534,8 +534,7 @@ protected function prepare_item_for_database( $request ) {
 		$prepared_post->post_name   = sanitize_title( $settings['slug'] );
 
 		// Remove duplicate information from settings.
-		unset( $settings['name'] );
-		unset( $settings['slug'] );
+		unset( $settings['name'], $settings['slug'] );
 
 		$prepared_post->post_content = wp_json_encode( $settings );
 
diff --git a/src/wp-includes/rest-api/endpoints/class-wp-rest-global-styles-revisions-controller.php b/src/wp-includes/rest-api/endpoints/class-wp-rest-global-styles-revisions-controller.php
index 54285fa560bee..0d3792c1ea8fd 100644
--- a/src/wp-includes/rest-api/endpoints/class-wp-rest-global-styles-revisions-controller.php
+++ b/src/wp-includes/rest-api/endpoints/class-wp-rest-global-styles-revisions-controller.php
@@ -213,7 +213,9 @@ public function get_items( $request ) {
 						__( 'The offset number requested is larger than or equal to the number of available revisions.' ),
 						array( 'status' => 400 )
 					);
-				} elseif ( ! $offset && $page > $max_pages ) {
+				}
+
+				if ( ! $offset && $page > $max_pages ) {
 					return new WP_Error(
 						'rest_revision_invalid_page_number',
 						__( 'The page number requested is larger than the number of pages available.' ),
diff --git a/src/wp-includes/rest-api/endpoints/class-wp-rest-menu-items-controller.php b/src/wp-includes/rest-api/endpoints/class-wp-rest-menu-items-controller.php
index ee69643813577..d5711e92a3818 100644
--- a/src/wp-includes/rest-api/endpoints/class-wp-rest-menu-items-controller.php
+++ b/src/wp-includes/rest-api/endpoints/class-wp-rest-menu-items-controller.php
@@ -1014,11 +1014,10 @@ protected function prepare_items_query( $prepared_args = array(), $request = nul
 	 */
 	protected function get_menu_id( $menu_item_id ) {
 		$menu_ids = wp_get_post_terms( $menu_item_id, 'nav_menu', array( 'fields' => 'ids' ) );
-		$menu_id  = 0;
 		if ( $menu_ids && ! is_wp_error( $menu_ids ) ) {
-			$menu_id = array_shift( $menu_ids );
+			return array_shift( $menu_ids );
 		}
 
-		return $menu_id;
+		return 0;
 	}
 }
diff --git a/src/wp-includes/rest-api/endpoints/class-wp-rest-navigation-fallback-controller.php b/src/wp-includes/rest-api/endpoints/class-wp-rest-navigation-fallback-controller.php
index 575a1a900e1d1..d696c39d1420e 100644
--- a/src/wp-includes/rest-api/endpoints/class-wp-rest-navigation-fallback-controller.php
+++ b/src/wp-includes/rest-api/endpoints/class-wp-rest-navigation-fallback-controller.php
@@ -106,9 +106,7 @@ public function get_item( $request ) {
 			return rest_ensure_response( new WP_Error( 'no_fallback_menu', __( 'No fallback menu found.' ), array( 'status' => 404 ) ) );
 		}
 
-		$response = $this->prepare_item_for_response( $post, $request );
-
-		return $response;
+		return $this->prepare_item_for_response( $post, $request );
 	}
 
 	/**
diff --git a/src/wp-includes/rest-api/endpoints/class-wp-rest-plugins-controller.php b/src/wp-includes/rest-api/endpoints/class-wp-rest-plugins-controller.php
index d0dd5fce4cd9c..00e14b93b2d1c 100644
--- a/src/wp-includes/rest-api/endpoints/class-wp-rest-plugins-controller.php
+++ b/src/wp-includes/rest-api/endpoints/class-wp-rest-plugins-controller.php
@@ -694,7 +694,10 @@ protected function get_plugin_status( $plugin ) {
 	 * @return true|WP_Error
 	 */
 	protected function plugin_status_permission_check( $plugin, $new_status, $current_status ) {
-		if ( is_multisite() && ( 'network-active' === $current_status || 'network-active' === $new_status ) && ! current_user_can( 'manage_network_plugins' ) ) {
+		if ( ( 'network-active' === $current_status || 'network-active' === $new_status )
+			&& is_multisite()
+			&& ! current_user_can( 'manage_network_plugins' )
+		) {
 			return new WP_Error(
 				'rest_cannot_manage_network_plugins',
 				__( 'Sorry, you are not allowed to manage network plugins.' ),
@@ -772,7 +775,7 @@ protected function handle_plugin_status( $plugin, $new_status, $current_status )
 	 * @return bool
 	 */
 	public function validate_plugin_param( $file ) {
-		if ( ! is_string( $file ) || ! preg_match( '/' . self::PATTERN . '/u', $file ) ) {
+		if ( ! is_string( $file ) || 1 !== preg_match( '/' . self::PATTERN . '/u', $file ) ) {
 			return false;
 		}
 
diff --git a/src/wp-includes/rest-api/endpoints/class-wp-rest-posts-controller.php b/src/wp-includes/rest-api/endpoints/class-wp-rest-posts-controller.php
index c4db4871df644..33d2eb877d98c 100644
--- a/src/wp-includes/rest-api/endpoints/class-wp-rest-posts-controller.php
+++ b/src/wp-includes/rest-api/endpoints/class-wp-rest-posts-controller.php
@@ -557,15 +557,13 @@ public function get_item_permissions_check( $request ) {
 			);
 		}
 
-		if ( $post && ! empty( $request->get_query_params()['password'] ) ) {
-			// Check post password, and return error if invalid.
-			if ( ! hash_equals( $post->post_password, $request->get_query_params()['password'] ) ) {
-				return new WP_Error(
-					'rest_post_incorrect_password',
-					__( 'Incorrect post password.' ),
-					array( 'status' => 403 )
-				);
-			}
+		// Check post password, and return error if invalid.
+		if ( $post && ! empty( $request->get_query_params()['password'] ) && ! hash_equals( $post->post_password, $request->get_query_params()['password'] ) ) {
+			return new WP_Error(
+				'rest_post_incorrect_password',
+				__( 'Incorrect post password.' ),
+				array( 'status' => 403 )
+			);
 		}
 
 		// Allow access to all password protected posts if the context is edit.
@@ -1199,7 +1197,7 @@ protected function prepare_items_query( $prepared_args = array(), $request = nul
 		}
 
 		// Map to proper WP_Query orderby param.
-		if ( isset( $query_args['orderby'] ) && isset( $request['orderby'] ) ) {
+		if ( isset( $query_args['orderby'], $request['orderby'] ) ) {
 			$orderby_mappings = array(
 				'id'            => 'ID',
 				'include'       => 'post__in',
@@ -1396,14 +1394,16 @@ protected function prepare_item_for_database( $request ) {
 			}
 		}
 
-		if ( ! empty( $schema['properties']['sticky'] ) && ! empty( $request['sticky'] ) ) {
-			if ( ! empty( $prepared_post->ID ) && post_password_required( $prepared_post->ID ) ) {
-				return new WP_Error(
-					'rest_invalid_field',
-					__( 'A password protected post can not be set to sticky.' ),
-					array( 'status' => 400 )
-				);
-			}
+		if ( ! empty( $schema['properties']['sticky'] )
+			&& ! empty( $request['sticky'] )
+			&& ! empty( $prepared_post->ID )
+			&& post_password_required( $prepared_post->ID )
+		) {
+			return new WP_Error(
+				'rest_invalid_field',
+				__( 'A password protected post can not be set to sticky.' ),
+				array( 'status' => 400 )
+			);
 		}
 
 		// Parent.
@@ -1551,16 +1551,15 @@ protected function handle_featured_media( $featured_media, $post_id ) {
 			$result = set_post_thumbnail( $post_id, $featured_media );
 			if ( $result ) {
 				return true;
-			} else {
-				return new WP_Error(
-					'rest_invalid_featured_media',
-					__( 'Invalid featured media ID.' ),
-					array( 'status' => 400 )
-				);
 			}
-		} else {
-			return delete_post_thumbnail( $post_id );
+			return new WP_Error(
+				'rest_invalid_featured_media',
+				__( 'Invalid featured media ID.' ),
+				array( 'status' => 400 )
+			);
 		}
+
+		return delete_post_thumbnail( $post_id );
 	}
 
 	/**
@@ -1649,6 +1648,8 @@ protected function handle_terms( $post_id, $request ) {
 				return $result;
 			}
 		}
+
+		return null;
 	}
 
 	/**
@@ -1696,11 +1697,7 @@ protected function check_is_post_type_allowed( $post_type ) {
 			$post_type = get_post_type_object( $post_type );
 		}
 
-		if ( ! empty( $post_type ) && ! empty( $post_type->show_in_rest ) ) {
-			return true;
-		}
-
-		return false;
+		return ! empty( $post_type ) && ! empty( $post_type->show_in_rest );
 	}
 
 	/**
@@ -1741,11 +1738,8 @@ public function check_read_permission( $post ) {
 		 * If there isn't a parent, but the status is set to inherit, assume
 		 * it's published (as per get_post_status()).
 		 */
-		if ( 'inherit' === $post->post_status ) {
-			return true;
-		}
 
-		return false;
+		return 'inherit' === $post->post_status;
 	}
 
 	/**
@@ -2008,12 +2002,8 @@ public function prepare_item_for_response( $item, $request ) {
 		}
 
 		if ( rest_is_field_included( 'template', $fields ) ) {
-			$template = get_page_template_slug( $post->ID );
-			if ( $template ) {
-				$data['template'] = $template;
-			} else {
-				$data['template'] = '';
-			}
+			$template         = get_page_template_slug( $post->ID );
+			$data['template'] = $template ? $template : '';
 		}
 
 		if ( rest_is_field_included( 'format', $fields ) ) {
@@ -2266,16 +2256,17 @@ protected function get_available_actions( $post, $request ) {
 			$rels[] = 'https://api.w.org/action-unfiltered-html';
 		}
 
-		if ( 'post' === $post_type->name ) {
-			if ( current_user_can( $post_type->cap->edit_others_posts ) && current_user_can( $post_type->cap->publish_posts ) ) {
-				$rels[] = 'https://api.w.org/action-sticky';
-			}
+		if ( 'post' === $post_type->name
+			&& current_user_can( $post_type->cap->edit_others_posts )
+			&& current_user_can( $post_type->cap->publish_posts )
+		) {
+			$rels[] = 'https://api.w.org/action-sticky';
 		}
 
-		if ( post_type_supports( $post_type->name, 'author' ) ) {
-			if ( current_user_can( $post_type->cap->edit_others_posts ) ) {
-				$rels[] = 'https://api.w.org/action-assign-author';
-			}
+		if ( post_type_supports( $post_type->name, 'author' )
+			&& current_user_can( $post_type->cap->edit_others_posts )
+		) {
+			$rels[] = 'https://api.w.org/action-assign-author';
 		}
 
 		$taxonomies = wp_list_filter( get_object_taxonomies( $this->post_type, 'objects' ), array( 'show_in_rest' => true ) );
@@ -2487,7 +2478,9 @@ public function get_item_schema() {
 		foreach ( $post_type_attributes as $attribute ) {
 			if ( isset( $fixed_schemas[ $this->post_type ] ) && ! in_array( $attribute, $fixed_schemas[ $this->post_type ], true ) ) {
 				continue;
-			} elseif ( ! isset( $fixed_schemas[ $this->post_type ] ) && ! post_type_supports( $this->post_type, $attribute ) ) {
+			}
+
+			if ( ! isset( $fixed_schemas[ $this->post_type ] ) && ! post_type_supports( $this->post_type, $attribute ) ) {
 				continue;
 			}
 
@@ -2721,7 +2714,7 @@ public function get_item_schema() {
 
 		// Emit a _doing_it_wrong warning if user tries to add new properties using this filter.
 		$new_fields = array_diff( array_keys( $schema['properties'] ), $schema_fields );
-		if ( count( $new_fields ) > 0 ) {
+		if ( array() !== $new_fields ) {
 			_doing_it_wrong(
 				__METHOD__,
 				sprintf(
diff --git a/src/wp-includes/rest-api/endpoints/class-wp-rest-revisions-controller.php b/src/wp-includes/rest-api/endpoints/class-wp-rest-revisions-controller.php
index fb5fa29231a4f..2b4cce0c5ee6c 100644
--- a/src/wp-includes/rest-api/endpoints/class-wp-rest-revisions-controller.php
+++ b/src/wp-includes/rest-api/endpoints/class-wp-rest-revisions-controller.php
@@ -320,7 +320,9 @@ public function get_items( $request ) {
 						__( 'The offset number requested is larger than or equal to the number of available revisions.' ),
 						array( 'status' => 400 )
 					);
-				} elseif ( ! $offset && $page > $max_pages ) {
+				}
+
+				if ( ! $offset && $page > $max_pages ) {
 					return new WP_Error(
 						'rest_revision_invalid_page_number',
 						__( 'The page number requested is larger than the number of pages available.' ),
@@ -473,7 +475,7 @@ public function delete_item( $request ) {
 			return $revision;
 		}
 
-		$force = isset( $request['force'] ) ? (bool) $request['force'] : false;
+		$force = isset( $request['force'] ) && $request['force'];
 
 		// We don't support trashing for revisions.
 		if ( ! $force ) {
@@ -538,7 +540,7 @@ protected function prepare_items_query( $prepared_args = array(), $request = nul
 		}
 
 		// Map to proper WP_Query orderby param.
-		if ( isset( $query_args['orderby'] ) && isset( $request['orderby'] ) ) {
+		if ( isset( $query_args['orderby'], $request['orderby'] ) ) {
 			$orderby_mappings = array(
 				'id'            => 'ID',
 				'include'       => 'post__in',
diff --git a/src/wp-includes/rest-api/endpoints/class-wp-rest-site-health-controller.php b/src/wp-includes/rest-api/endpoints/class-wp-rest-site-health-controller.php
index 41e15337add5f..7b355f02e1858 100644
--- a/src/wp-includes/rest-api/endpoints/class-wp-rest-site-health-controller.php
+++ b/src/wp-includes/rest-api/endpoints/class-wp-rest-site-health-controller.php
@@ -295,19 +295,15 @@ public function get_directory_sizes() {
 			$data = array();
 
 			if ( isset( $value['size'] ) ) {
-				if ( is_string( $value['size'] ) ) {
-					$data['size'] = sanitize_text_field( $value['size'] );
-				} else {
-					$data['size'] = (int) $value['size'];
-				}
+				$data['size'] = is_string( $value['size'] )
+					? sanitize_text_field( $value['size'] )
+					: (int) $value['size'];
 			}
 
 			if ( isset( $value['debug'] ) ) {
-				if ( is_string( $value['debug'] ) ) {
-					$data['debug'] = sanitize_text_field( $value['debug'] );
-				} else {
-					$data['debug'] = (int) $value['debug'];
-				}
+				$data['debug'] = is_string( $value['debug'] )
+					? sanitize_text_field( $value['debug'] )
+					: (int) $value['debug'];
 			}
 
 			if ( ! empty( $value['raw'] ) ) {
diff --git a/src/wp-includes/rest-api/endpoints/class-wp-rest-taxonomies-controller.php b/src/wp-includes/rest-api/endpoints/class-wp-rest-taxonomies-controller.php
index 0b15f3494c4b5..13af63c8ef0cf 100644
--- a/src/wp-includes/rest-api/endpoints/class-wp-rest-taxonomies-controller.php
+++ b/src/wp-includes/rest-api/endpoints/class-wp-rest-taxonomies-controller.php
@@ -126,7 +126,11 @@ public function get_items( $request ) {
 		$data = array();
 
 		foreach ( $taxonomies as $tax_type => $value ) {
-			if ( empty( $value->show_in_rest ) || ( 'edit' === $request['context'] && ! current_user_can( $value->cap->assign_terms ) ) ) {
+			if ( empty( $value->show_in_rest ) ) {
+				continue;
+			}
+
+			if ( 'edit' === $request['context'] && ! current_user_can( $value->cap->assign_terms ) ) {
 				continue;
 			}
 
@@ -441,12 +445,12 @@ public function get_item_schema() {
 	 * @return array Collection parameters.
 	 */
 	public function get_collection_params() {
-		$new_params            = array();
-		$new_params['context'] = $this->get_context_param( array( 'default' => 'view' ) );
-		$new_params['type']    = array(
-			'description' => __( 'Limit results to taxonomies associated with a specific post type.' ),
-			'type'        => 'string',
+		return array(
+			'context' => $this->get_context_param( array( 'default' => 'view' ) ),
+			'type'    => array(
+				'description' => __( 'Limit results to taxonomies associated with a specific post type.' ),
+				'type'        => 'string',
+			),
 		);
-		return $new_params;
 	}
 }
diff --git a/src/wp-includes/rest-api/endpoints/class-wp-rest-template-autosaves-controller.php b/src/wp-includes/rest-api/endpoints/class-wp-rest-template-autosaves-controller.php
index c996894a5933c..bc7059c28ce40 100644
--- a/src/wp-includes/rest-api/endpoints/class-wp-rest-template-autosaves-controller.php
+++ b/src/wp-includes/rest-api/endpoints/class-wp-rest-template-autosaves-controller.php
@@ -220,8 +220,7 @@ public function get_item( $request ) {
 			);
 		}
 
-		$response = $this->prepare_item_for_response( $autosave, $request );
-		return $response;
+		return $this->prepare_item_for_response( $autosave, $request );
 	}
 
 	/**
diff --git a/src/wp-includes/rest-api/endpoints/class-wp-rest-templates-controller.php b/src/wp-includes/rest-api/endpoints/class-wp-rest-templates-controller.php
index 43780fb4e677b..9f26e030c5039 100644
--- a/src/wp-includes/rest-api/endpoints/class-wp-rest-templates-controller.php
+++ b/src/wp-includes/rest-api/endpoints/class-wp-rest-templates-controller.php
@@ -459,7 +459,7 @@ public function create_item( $request ) {
 			return $post_id;
 		}
 		$posts = get_block_templates( array( 'wp_id' => $post_id ), $this->post_type );
-		if ( ! count( $posts ) ) {
+		if ( 0 === count( $posts ) ) {
 			return new WP_Error( 'rest_template_insert_error', __( 'No templates exist with that id.' ), array( 'status' => 400 ) );
 		}
 		$id            = $posts[0]->id;
diff --git a/src/wp-includes/rest-api/endpoints/class-wp-rest-terms-controller.php b/src/wp-includes/rest-api/endpoints/class-wp-rest-terms-controller.php
index 78c9d1ca2b0d8..7b12ff138397a 100644
--- a/src/wp-includes/rest-api/endpoints/class-wp-rest-terms-controller.php
+++ b/src/wp-includes/rest-api/endpoints/class-wp-rest-terms-controller.php
@@ -165,12 +165,7 @@ public function check_read_terms_permission_for_post( $post, $request ) {
 		}
 
 		// Otherwise grant access if the post is readable by the logged-in user.
-		if ( current_user_can( 'read_post', $post->ID ) ) {
-			return true;
-		}
-
-		// Otherwise, deny access.
-		return false;
+		return current_user_can( 'read_post', $post->ID );
 	}
 
 	/**
@@ -288,10 +283,8 @@ public function get_items( $request ) {
 			if ( 0 === $request['parent'] ) {
 				// Only query top-level terms.
 				$prepared_args['parent'] = 0;
-			} else {
-				if ( $request['parent'] ) {
-					$prepared_args['parent'] = $request['parent'];
-				}
+			} elseif ( $request['parent'] ) {
+				$prepared_args['parent'] = $request['parent'];
 			}
 		}
 
@@ -743,7 +736,7 @@ public function delete_item( $request ) {
 			return $term;
 		}
 
-		$force = isset( $request['force'] ) ? (bool) $request['force'] : false;
+		$force = isset( $request['force'] ) && $request['force'];
 
 		// We don't support trashing for terms.
 		if ( ! $force ) {
@@ -1203,9 +1196,7 @@ public function get_collection_params() {
 	 */
 	protected function check_is_taxonomy_allowed( $taxonomy ) {
 		$taxonomy_obj = get_taxonomy( $taxonomy );
-		if ( $taxonomy_obj && ! empty( $taxonomy_obj->show_in_rest ) ) {
-			return true;
-		}
-		return false;
+
+		return $taxonomy_obj && ! empty( $taxonomy_obj->show_in_rest );
 	}
 }
diff --git a/src/wp-includes/rest-api/endpoints/class-wp-rest-themes-controller.php b/src/wp-includes/rest-api/endpoints/class-wp-rest-themes-controller.php
index be12707b3c750..e0a9c6801ee28 100644
--- a/src/wp-includes/rest-api/endpoints/class-wp-rest-themes-controller.php
+++ b/src/wp-includes/rest-api/endpoints/class-wp-rest-themes-controller.php
@@ -623,7 +623,7 @@ public function get_item_schema() {
 			),
 		);
 
-		foreach ( get_registered_theme_features() as $feature => $config ) {
+		foreach ( get_registered_theme_features() as $config ) {
 			if ( ! is_array( $config['show_in_rest'] ) ) {
 				continue;
 			}
diff --git a/src/wp-includes/rest-api/endpoints/class-wp-rest-url-details-controller.php b/src/wp-includes/rest-api/endpoints/class-wp-rest-url-details-controller.php
index ab126f981c340..5e7eb0be2d665 100644
--- a/src/wp-includes/rest-api/endpoints/class-wp-rest-url-details-controller.php
+++ b/src/wp-includes/rest-api/endpoints/class-wp-rest-url-details-controller.php
@@ -150,7 +150,7 @@ public function parse_url_details( $request ) {
 			$remote_url_response = $this->get_remote_url( $url );
 
 			// Exit if we don't have a valid body or it's empty.
-			if ( is_wp_error( $remote_url_response ) || empty( $remote_url_response ) ) {
+			if ( empty( $remote_url_response ) || is_wp_error( $remote_url_response ) ) {
 				return $remote_url_response;
 			}
 
@@ -333,7 +333,7 @@ private function get_icon( $html, $url ) {
 			return $icon;
 		}
 		$parsed_url = parse_url( $url );
-		if ( isset( $parsed_url['scheme'] ) && isset( $parsed_url['host'] ) ) {
+		if ( isset( $parsed_url['scheme'], $parsed_url['host'] ) ) {
 			$root_url = $parsed_url['scheme'] . '://' . $parsed_url['host'] . '/';
 			$icon     = WP_Http::make_absolute_url( $icon, $root_url );
 		}
@@ -406,7 +406,7 @@ private function get_image( $meta_elements, $url ) {
 
 		// Attempt to convert relative URLs to absolute.
 		$parsed_url = parse_url( $url );
-		if ( isset( $parsed_url['scheme'] ) && isset( $parsed_url['host'] ) ) {
+		if ( isset( $parsed_url['scheme'], $parsed_url['host'] ) ) {
 			$root_url = $parsed_url['scheme'] . '://' . $parsed_url['host'] . '/';
 			$image    = WP_Http::make_absolute_url( $image, $root_url );
 		}
@@ -426,8 +426,8 @@ private function get_image( $meta_elements, $url ) {
 	 */
 	private function prepare_metadata_for_output( $metadata ) {
 		$metadata = html_entity_decode( $metadata, ENT_QUOTES, get_bloginfo( 'charset' ) );
-		$metadata = wp_strip_all_tags( $metadata );
-		return $metadata;
+
+		return wp_strip_all_tags( $metadata );
 	}
 
 	/**
diff --git a/src/wp-includes/rest-api/endpoints/class-wp-rest-users-controller.php b/src/wp-includes/rest-api/endpoints/class-wp-rest-users-controller.php
index c8d9b11a11d20..e5df77851e3a1 100644
--- a/src/wp-includes/rest-api/endpoints/class-wp-rest-users-controller.php
+++ b/src/wp-includes/rest-api/endpoints/class-wp-rest-users-controller.php
@@ -455,7 +455,9 @@ public function get_item_permissions_check( $request ) {
 				__( 'Sorry, you are not allowed to list users.' ),
 				array( 'status' => rest_authorization_required_code() )
 			);
-		} elseif ( ! count_user_posts( $user->ID, $types ) && ! current_user_can( 'edit_user', $user->ID ) && ! current_user_can( 'list_users' ) ) {
+		}
+
+		if ( ! count_user_posts( $user->ID, $types ) && ! current_user_can( 'edit_user', $user->ID ) && ! current_user_can( 'list_users' ) ) {
 			return new WP_Error(
 				'rest_user_cannot_view',
 				__( 'Sorry, you are not allowed to list users.' ),
@@ -480,10 +482,9 @@ public function get_item( $request ) {
 			return $user;
 		}
 
-		$user     = $this->prepare_item_for_response( $user, $request );
-		$response = rest_ensure_response( $user );
+		$user = $this->prepare_item_for_response( $user, $request );
 
-		return $response;
+		return rest_ensure_response( $user );
 	}
 
 	/**
@@ -507,9 +508,8 @@ public function get_current_item( $request ) {
 
 		$user     = wp_get_current_user();
 		$response = $this->prepare_item_for_response( $user, $request );
-		$response = rest_ensure_response( $response );
 
-		return $response;
+		return rest_ensure_response( $response );
 	}
 
 	/**
@@ -812,9 +812,8 @@ public function update_item( $request ) {
 		do_action( 'rest_after_insert_user', $user, $request, false );
 
 		$response = $this->prepare_item_for_response( $user, $request );
-		$response = rest_ensure_response( $response );
 
-		return $response;
+		return rest_ensure_response( $response );
 	}
 
 	/**
@@ -896,7 +895,7 @@ public function delete_item( $request ) {
 
 		$id       = $user->ID;
 		$reassign = false === $request['reassign'] ? null : absint( $request['reassign'] );
-		$force    = isset( $request['force'] ) ? (bool) $request['force'] : false;
+		$force    = isset( $request['force'] ) && $request['force'];
 
 		// We don't support trashing for users.
 		if ( ! $force ) {
@@ -908,14 +907,14 @@ public function delete_item( $request ) {
 			);
 		}
 
-		if ( ! empty( $reassign ) ) {
-			if ( $reassign === $id || ! get_userdata( $reassign ) ) {
-				return new WP_Error(
-					'rest_user_invalid_reassign',
-					__( 'Invalid user ID for reassignment.' ),
-					array( 'status' => 400 )
-				);
-			}
+		if ( ! empty( $reassign )
+			&& ( $reassign === $id || ! get_userdata( $reassign ) )
+		) {
+			return new WP_Error(
+				'rest_user_invalid_reassign',
+				__( 'Invalid user ID for reassignment.' ),
+				array( 'status' => 400 )
+			);
 		}
 
 		$request->set_param( 'context', 'edit' );
diff --git a/src/wp-includes/rest-api/endpoints/class-wp-rest-widgets-controller.php b/src/wp-includes/rest-api/endpoints/class-wp-rest-widgets-controller.php
index f2d17186b62d7..5746ab5f48cff 100644
--- a/src/wp-includes/rest-api/endpoints/class-wp-rest-widgets-controller.php
+++ b/src/wp-includes/rest-api/endpoints/class-wp-rest-widgets-controller.php
@@ -328,11 +328,11 @@ public function update_item( $request ) {
 			}
 		}
 
-		if ( $request->has_param( 'sidebar' ) ) {
-			if ( $sidebar_id !== $request['sidebar'] ) {
-				$sidebar_id = $request['sidebar'];
-				wp_assign_widget_to_sidebar( $widget_id, $sidebar_id );
-			}
+		if ( $request->has_param( 'sidebar' )
+			&& $sidebar_id !== $request['sidebar']
+		) {
+			$sidebar_id = $request['sidebar'];
+			wp_assign_widget_to_sidebar( $widget_id, $sidebar_id );
 		}
 
 		$request['context'] = 'edit';
@@ -690,9 +690,8 @@ public function prepare_item_for_response( $item, $request ) {
 			'instance'      => null,
 		);
 
-		if (
-			rest_is_field_included( 'rendered', $fields ) &&
-			'wp_inactive_widgets' !== $sidebar_id
+		if ( 'wp_inactive_widgets' !== $sidebar_id
+			&& rest_is_field_included( 'rendered', $fields )
 		) {
 			$prepared['rendered'] = trim( wp_render_widget( $widget_id, $sidebar_id ) );
 		}
diff --git a/src/wp-includes/rest-api/fields/class-wp-rest-meta-fields.php b/src/wp-includes/rest-api/fields/class-wp-rest-meta-fields.php
index aa0bc644bc1ce..1f85ba78488a6 100644
--- a/src/wp-includes/rest-api/fields/class-wp-rest-meta-fields.php
+++ b/src/wp-includes/rest-api/fields/class-wp-rest-meta-fields.php
@@ -85,12 +85,7 @@ public function get_value( $object_id, $request ) {
 			$all_values = get_metadata( $this->get_meta_type(), $object_id, $meta_key, false );
 
 			if ( $args['single'] ) {
-				if ( empty( $all_values ) ) {
-					$value = $args['schema']['default'];
-				} else {
-					$value = $all_values[0];
-				}
-
+				$value = empty( $all_values ) ? $args['schema']['default'] : $all_values[0];
 				$value = $this->prepare_value_for_response( $value, $request, $args );
 			} else {
 				$value = array();
@@ -322,8 +317,7 @@ function ( $stored_value ) use ( $meta_key, $subtype, $value ) {
 
 			$remove_key = $remove_keys[0];
 
-			unset( $to_remove[ $remove_key ] );
-			unset( $to_add[ $add_key ] );
+			unset( $to_remove[ $remove_key ], $to_add[ $add_key ] );
 		}
 
 		/*
@@ -554,11 +548,7 @@ public function get_field_schema() {
 	 * @return mixed Value prepared for output. If a non-JsonSerializable object, null.
 	 */
 	public static function prepare_value( $value, $request, $args ) {
-		if ( $args['single'] ) {
-			$schema = $args['schema'];
-		} else {
-			$schema = $args['schema']['items'];
-		}
+		$schema = $args['single'] ? $args['schema'] : $args['schema']['items'];
 
 		if ( '' === $value && in_array( $schema['type'], array( 'boolean', 'integer', 'number' ), true ) ) {
 			$value = static::get_empty_value_for_type( $schema['type'] );