Clean up comments, fix some code review issues, and make the exit code optional throughout to make it clear that it isn't always a number

src/vs/workbench/api/node/extHost.protocol.ts

@@ -554,7 +554,7 @@ export interface MainThreadTaskShape extends IDisposable {
 	$executeTask(task: TaskHandleDTO | TaskDTO): Promise<TaskExecutionDTO>;
 	$terminateTask(id: string): Promise<void>;
 	$registerTaskSystem(scheme: string, info: TaskSystemInfoDTO): void;
-	$customTaskExecutionComplete(id: string, result: number | undefined): Promise<void>;
+	$customTaskExecutionComplete(id: string, result?: number): Promise<void>;
 }
 
 export interface MainThreadExtensionServiceShape extends IDisposable {

src/vs/workbench/api/node/extHostTask.ts

@@ -403,7 +403,7 @@ class CustomTaskExecutionData implements IDisposable {
 
 		this._disposables.push(this.terminalService.onDidCloseTerminal(this.onDidCloseTerminal.bind(this)));
 
-		// Regardless of how the task completes, we are done with this extension callback task execution.
+		// Regardless of how the task completes, we are done with this custom execution task.
 		this.callbackData.callback(terminalRenderer, this._cancellationSource.token).then(
 			(success) => {
 				this.result = success;
@@ -515,8 +515,7 @@ export class ExtHostTask implements ExtHostTaskShape {
 	}
 
 	public async $onDidStartTask(execution: TaskExecutionDTO, terminalId: number): Promise<void> {
-		// Once a terminal is spun up for the extension callback task execution
-		// this event will be fired.
+		// Once a terminal is spun up for the custom execution task this event will be fired.
 		// At that point, we need to actually start the callback, but
 		// only if it hasn't already begun.
 		const extensionCallback: CustomTaskExecutionData | undefined = this._providedCustomTaskExecutions.get(execution.id);
@@ -591,19 +590,19 @@ export class ExtHostTask implements ExtHostTaskShape {
 			return Promise.reject(new Error('no handler found'));
 		}
 
-		// For extension callback tasks, we need to store the execution objects locally
+		// For custom execution tasks, we need to store the execution objects locally
 		// since we obviously cannot send callback functions through the proxy.
 		// So, clear out any existing ones.
 		this._providedCustomTaskExecutions.clear();
 
 		// Set up a list of task ID promises that we can wait on
 		// before returning the provided tasks. The ensures that
-		// our task IDs are calculated for any extension callback tasks.
+		// our task IDs are calculated for any custom execution tasks.
 		// Knowing this ID ahead of time is needed because when a task
-		// start event is fired this is when the extension callback is called.
+		// start event is fired this is when the custom execution is called.
 		// The task start event is also the first time we see the ID from the main
 		// thread, which is too late for us because we need to save an map
-		// from an ID to an extension callback function. (Kind of a cart before the horse problem).
+		// from an ID to the custom execution function. (Kind of a cart before the horse problem).
 		let taskIdPromises: Promise<void>[] = [];
 		let fetchPromise = asPromise(() => handler.provider.provideTasks(CancellationToken.None)).then(value => {
 			const taskDTOs: TaskDTO[] = [];

src/vs/workbench/api/node/extHostTerminalService.ts

@@ -288,7 +288,6 @@ export class ExtHostTerminalService implements ExtHostTerminalServiceShape {
 
 	public get activeTerminal(): ExtHostTerminal { return this._activeTerminal; }
 	public get terminals(): ExtHostTerminal[] { return this._terminals; }
-	public get terminalRenderers(): ExtHostTerminalRenderer[] { return this._terminalRenderers; }
 
 	private readonly _onDidCloseTerminal: Emitter<vscode.Terminal> = new Emitter<vscode.Terminal>();
 	public get onDidCloseTerminal(): Event<vscode.Terminal> { return this._onDidCloseTerminal && this._onDidCloseTerminal.event; }
@@ -338,7 +337,7 @@ export class ExtHostTerminalService implements ExtHostTerminalServiceShape {
 			throw new Error('Only expected instance extension host terminal type');
 		}
 		// Check to see if the extension host already knows about this terminal.
-		for (const terminalRenderer of this.terminalRenderers) {
+		for (const terminalRenderer of this._terminalRenderers) {
 			if (terminalRenderer._id === terminal._id) {
 				return terminalRenderer;
 			}