src/vs/workbench/contrib/tasks/browser/abstractTaskService.ts/AbstractTaskService/_runTest
class AbstractTaskService:	private async _runTest(): Promise<ITaskSummary> {
		const tryTestShortcut = await this._findSingleWorkspaceTaskOfGroup(TaskGroup.Test);
		if (tryTestShortcut) {
			return tryTestShortcut;
		}

		return this._getGroupedTasks().then((tasks) => {
			const runnable = this._createRunnableTask(tasks, TaskGroup.Test);
			if (!runnable || !runnable.task) {
				if (this.schemaVersion === JsonSchemaVersion.V0_1_0) {
					throw new TaskError(Severity.Info, nls.localize('TaskService.noTestTask1', 'No test task defined. Mark a task with \'isTestCommand\' in the tasks.json file.'), TaskErrors.NoTestTask);
				} else {
					throw new TaskError(Severity.Info, nls.localize('TaskService.noTestTask2', 'No test task defined. Mark a task with as a \'test\' group in the tasks.json file.'), TaskErrors.NoTestTask);
				}
			}
			return this._executeTask(runnable.task, runnable.resolver, TaskRunSource.User);
		}).then(value => value, (error) => {
			this._handleError(error);
			return Promise.reject(error);
		});
	}