Fixing some strict null errors in mainThread

src/vs/workbench/api/electron-browser/mainThreadClipboard.ts

@@ -20,6 +20,6 @@ export class MainThreadCommands implements MainThreadClipboardShape {
 
 	$writeText(value: string): Promise<void> {
 		clipboard.writeText(value);
-		return undefined;
+		return Promise.resolve();
 	}
 }

src/vs/workbench/api/electron-browser/mainThreadCommands.ts

@@ -64,13 +64,14 @@ export class MainThreadCommands implements MainThreadCommandsShape {
 	}
 
 	$unregisterCommand(id: string): void {
-		if (this._disposables.has(id)) {
-			this._disposables.get(id).dispose();
+		const command = this._disposables.get(id);
+		if (command) {
+			command.dispose();
 			this._disposables.delete(id);
 		}
 	}
 
-	$executeCommand<T>(id: string, args: any[]): Promise<T> {
+	$executeCommand<T>(id: string, args: any[]): Promise<T | undefined> {
 		for (let i = 0; i < args.length; i++) {
 			args[i] = revive(args[i], 0);
 		}

src/vs/workbench/api/electron-browser/mainThreadFileSystem.ts

@@ -44,7 +44,11 @@ export class MainThreadFileSystem implements MainThreadFileSystemShape {
 	}
 
 	$onFileSystemChange(handle: number, changes: IFileChangeDto[]): void {
-		this._fileProvider.get(handle).$onFileSystemChange(changes);
+		const fileProvider = this._fileProvider.get(handle);
+		if (!fileProvider) {
+			throw new Error('Unknown file provider');
+		}
+		fileProvider.$onFileSystemChange(changes);
 	}
 }
 

src/vs/workbench/api/electron-browser/mainThreadFileSystemEventService.ts

@@ -52,7 +52,7 @@ export class MainThreadFileSystemEventService {
 		// file operation events - (changes the editor makes)
 		fileService.onAfterOperation(e => {
 			if (e.operation === FileOperation.MOVE) {
-				proxy.$onFileRename(e.resource, e.target.resource);
+				proxy.$onFileRename(e.resource, e.target.resource!);
 			}
 		}, undefined, this._listener);