Make sure we use the more specific custom document type in interfaces

src/vs/vscode.proposed.d.ts

@@ -1247,12 +1247,12 @@ declare module 'vscode' {
 	 *
 	 * @see [`CustomDocumentProvider.onDidChangeCustomDocument`](#CustomDocumentProvider.onDidChangeCustomDocument).
 	 */
-	interface CustomDocumentEditEvent {
+	interface CustomDocumentEditEvent<T extends CustomDocument = CustomDocument> {
 
 		/**
 		 * The document that the edit is for.
 		 */
-		readonly document: CustomDocument;
+		readonly document: T;
 
 		/**
 		 * Undo the edit operation.
@@ -1282,11 +1282,11 @@ declare module 'vscode' {
 	 *
 	 * @see [`CustomDocumentProvider.onDidChangeCustomDocument`](#CustomDocumentProvider.onDidChangeCustomDocument).
 	 */
-	interface CustomDocumentContentChangeEvent {
+	interface CustomDocumentContentChangeEvent<T extends CustomDocument = CustomDocument> {
 		/**
 		 * The document that the change is for.
 		 */
-		readonly document: CustomDocument;
+		readonly document: T;
 	}
 
 	/**
@@ -1404,7 +1404,7 @@ declare module 'vscode' {
 		 *
 		 * An editor should only ever fire `CustomDocumentEditEvent` events, or only ever fire `CustomDocumentContentChangeEvent` events.
 		 */
-		readonly onDidChangeCustomDocument: Event<CustomDocumentEditEvent> | Event<CustomDocumentContentChangeEvent>;
+		readonly onDidChangeCustomDocument: Event<CustomDocumentEditEvent<T>> | Event<CustomDocumentContentChangeEvent<T>>;
 
 		/**
 		 * Save a custom document.
@@ -1421,7 +1421,7 @@ declare module 'vscode' {
 		 *
 		 * @return Thenable signaling that saving has completed.
 		 */
-		saveCustomDocument(document: CustomDocument, cancellation: CancellationToken): Thenable<void>;
+		saveCustomDocument(document: T, cancellation: CancellationToken): Thenable<void>;
 
 		/**
 		 * Save a custom document to a different location.
@@ -1437,7 +1437,7 @@ declare module 'vscode' {
 		 *
 		 * @return Thenable signaling that saving has completed.
 		 */
-		saveCustomDocumentAs(document: CustomDocument, destination: Uri, cancellation: CancellationToken): Thenable<void>;
+		saveCustomDocumentAs(document: T, destination: Uri, cancellation: CancellationToken): Thenable<void>;
 
 		/**
 		 * Revert a custom document to its last saved state.
@@ -1457,7 +1457,7 @@ declare module 'vscode' {
 		 *
 		 * @return Thenable signaling that the change has completed.
 		 */
-		revertCustomDocument(document: CustomDocument, cancellation: CancellationToken): Thenable<void>;
+		revertCustomDocument(document: T, cancellation: CancellationToken): Thenable<void>;
 
 		/**
 		 * Back up a dirty custom document.
@@ -1479,7 +1479,7 @@ declare module 'vscode' {
 		 * in an operation that takes time to complete, your extension may decide to finish the ongoing backup rather
 		 * than cancelling it to ensure that VS Code has some valid backup.
 		 */
-		backupCustomDocument(document: CustomDocument, context: CustomDocumentBackupContext, cancellation: CancellationToken): Thenable<CustomDocumentBackup>;
+		backupCustomDocument(document: T, context: CustomDocumentBackupContext, cancellation: CancellationToken): Thenable<CustomDocumentBackup>;
 	}
 
 	namespace window {