Avoid passing circular callback into CoreService ctor

src/common/services/CoreService.test.ts

@@ -13,7 +13,6 @@ describe('CoreService', () => {
 
   beforeEach(() => {
     coreService = new CoreService(
-      () => {},
       new MockBufferService(80, 30),
       new MockLogService(),
       new MockOptionsService());

src/common/services/CoreService.ts

@@ -31,26 +31,21 @@ export class CoreService extends Disposable implements ICoreService {
   public modes: IModes;
   public decPrivateModes: IDecPrivateModes;
 
-  // Circular dependency, this must be unset or memory will leak after Terminal.dispose
-  private _scrollToBottom: (() => void) | undefined;
-
   private readonly _onData = this.register(new EventEmitter<string>());
   public readonly onData = this._onData.event;
   private readonly _onUserInput = this.register(new EventEmitter<void>());
   public readonly onUserInput = this._onUserInput.event;
   private readonly _onBinary = this.register(new EventEmitter<string>());
   public readonly onBinary = this._onBinary.event;
+  private readonly _onRequestScrollToBottom = this.register(new EventEmitter<void>());
+  public readonly onRequestScrollToBottom = this._onRequestScrollToBottom.event;
 
   constructor(
-    // TODO: Move this into a service
-    scrollToBottom: () => void,
     @IBufferService private readonly _bufferService: IBufferService,
     @ILogService private readonly _logService: ILogService,
     @IOptionsService private readonly _optionsService: IOptionsService
   ) {
     super();
-    this._scrollToBottom = scrollToBottom;
-    this.register({ dispose: () => this._scrollToBottom = undefined });
     this.modes = clone(DEFAULT_MODES);
     this.decPrivateModes = clone(DEFAULT_DEC_PRIVATE_MODES);
   }
@@ -69,7 +64,7 @@ export class CoreService extends Disposable implements ICoreService {
     // Input is being sent to the terminal, the terminal should focus the prompt.
     const buffer = this._bufferService.buffer;
     if (buffer.ybase !== buffer.ydisp) {
-      this._scrollToBottom!();
+      this._onRequestScrollToBottom.fire();
     }
 
     // Fire onUserInput so listeners can react as well (eg. clear selection)

src/common/services/Services.ts

@@ -79,6 +79,7 @@ export interface ICoreService {
   readonly onData: IEvent<string>;
   readonly onUserInput: IEvent<void>;
   readonly onBinary: IEvent<string>;
+  readonly onRequestScrollToBottom: IEvent<void>;
 
   reset(): void;