Add tests for undo-redo

src/vs/platform/undoRedo/test/common/undoRedoService.test.ts

+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+import * as assert from 'assert';
+import { UndoRedoService } from 'vs/platform/undoRedo/common/undoRedoService';
+import { TestDialogService } from 'vs/platform/dialogs/test/common/testDialogService';
+import { TestNotificationService } from 'vs/platform/notification/test/common/testNotificationService';
+import { UndoRedoElementType, IUndoRedoElement } from 'vs/platform/undoRedo/common/undoRedo';
+import { URI } from 'vs/base/common/uri';
+
+suite('UndoRedoService', () => {
+
+	function createUndoRedoService(): UndoRedoService {
+		const dialogService = new TestDialogService();
+		const notificationService = new TestNotificationService();
+		return new UndoRedoService(dialogService, notificationService);
+	}
+
+	test('simple single element', () => {
+		const resource = URI.file('test.txt');
+		const service = createUndoRedoService();
+
+		assert.equal(service.canUndo(resource), false);
+		assert.equal(service.canRedo(resource), false);
+		assert.equal(service.hasElements(resource), false);
+		assert.ok(service.getLastElement(resource) === null);
+
+		let undoCall1 = 0;
+		let redoCall1 = 0;
+		const element1: IUndoRedoElement = {
+			type: UndoRedoElementType.Resource,
+			resource: resource,
+			label: 'typing 1',
+			undo: () => { undoCall1++; },
+			redo: () => { redoCall1++; }
+		};
+		service.pushElement(element1);
+
+		assert.equal(undoCall1, 0);
+		assert.equal(redoCall1, 0);
+		assert.equal(service.canUndo(resource), true);
+		assert.equal(service.canRedo(resource), false);
+		assert.equal(service.hasElements(resource), true);
+		assert.ok(service.getLastElement(resource) === element1);
+
+		service.undo(resource);
+		assert.equal(undoCall1, 1);
+		assert.equal(redoCall1, 0);
+		assert.equal(service.canUndo(resource), false);
+		assert.equal(service.canRedo(resource), true);
+		assert.equal(service.hasElements(resource), true);
+		assert.ok(service.getLastElement(resource) === null);
+
+		service.redo(resource);
+		assert.equal(undoCall1, 1);
+		assert.equal(redoCall1, 1);
+		assert.equal(service.canUndo(resource), true);
+		assert.equal(service.canRedo(resource), false);
+		assert.equal(service.hasElements(resource), true);
+		assert.ok(service.getLastElement(resource) === element1);
+
+		let undoCall2 = 0;
+		let redoCall2 = 0;
+		const element2: IUndoRedoElement = {
+			type: UndoRedoElementType.Resource,
+			resource: resource,
+			label: 'typing 2',
+			undo: () => { undoCall2++; },
+			redo: () => { redoCall2++; }
+		};
+		service.pushElement(element2);
+
+		assert.equal(undoCall1, 1);
+		assert.equal(redoCall1, 1);
+		assert.equal(undoCall2, 0);
+		assert.equal(redoCall2, 0);
+		assert.equal(service.canUndo(resource), true);
+		assert.equal(service.canRedo(resource), false);
+		assert.equal(service.hasElements(resource), true);
+		assert.ok(service.getLastElement(resource) === element2);
+
+		service.undo(resource);
+
+		assert.equal(undoCall1, 1);
+		assert.equal(redoCall1, 1);
+		assert.equal(undoCall2, 1);
+		assert.equal(redoCall2, 0);
+		assert.equal(service.canUndo(resource), true);
+		assert.equal(service.canRedo(resource), true);
+		assert.equal(service.hasElements(resource), true);
+		assert.ok(service.getLastElement(resource) === null);
+
+		let undoCall3 = 0;
+		let redoCall3 = 0;
+		const element3: IUndoRedoElement = {
+			type: UndoRedoElementType.Resource,
+			resource: resource,
+			label: 'typing 2',
+			undo: () => { undoCall3++; },
+			redo: () => { redoCall3++; }
+		};
+		service.pushElement(element3);
+
+		assert.equal(undoCall1, 1);
+		assert.equal(redoCall1, 1);
+		assert.equal(undoCall2, 1);
+		assert.equal(redoCall2, 0);
+		assert.equal(undoCall3, 0);
+		assert.equal(redoCall3, 0);
+		assert.equal(service.canUndo(resource), true);
+		assert.equal(service.canRedo(resource), false);
+		assert.equal(service.hasElements(resource), true);
+		assert.ok(service.getLastElement(resource) === element3);
+
+		service.undo(resource);
+
+		assert.equal(undoCall1, 1);
+		assert.equal(redoCall1, 1);
+		assert.equal(undoCall2, 1);
+		assert.equal(redoCall2, 0);
+		assert.equal(undoCall3, 1);
+		assert.equal(redoCall3, 0);
+		assert.equal(service.canUndo(resource), true);
+		assert.equal(service.canRedo(resource), true);
+		assert.equal(service.hasElements(resource), true);
+		assert.ok(service.getLastElement(resource) === null);
+	});
+
+});