Try adding attachment trashable status to REST API

Author: tellthemachines

src/wp-includes/rest-api/endpoints/class-wp-rest-attachments-controller.php

@@ -941,6 +941,10 @@ public function prepare_item_for_response( $item, $request ) {
 			$data['missing_image_sizes'] = array_keys( wp_get_missing_image_subsizes( $post->ID ) );
 		}
 
+		if ( in_array( 'trashable', $fields, true ) ) {
+			$data['trashable'] = ( defined( 'MEDIA_TRASH' ) && MEDIA_TRASH );
+		}
+
 		$context = ! empty( $request['context'] ) ? $request['context'] : 'view';
 
 		$data = $this->filter_response_by_context( $data, $context );
@@ -1083,6 +1087,13 @@ public function get_item_schema() {
 			'readonly'    => true,
 		);
 
+		$schema['properties']['trashable'] = array(
+			'description' => __( 'Whether the attachment can be moved to the trash.' ),
+			'type'        => 'boolean',
+			'context'     => array( 'view', 'edit' ),
+			'readonly'    => true,
+		);
+
 		unset( $schema['properties']['password'] );
 
 		$this->schema = $schema;