[FIX] AbstractBuilder: Multiple custom task executions did not run

lib/types/AbstractBuilder.js

@@ -190,6 +190,8 @@ class AbstractBuilder {
 	 * @returns {boolean}
 	 */
 	hasTask(taskName) {
+		// TODO 3.0: Check whether this method is still required.
+		// Only usage within #build seems to be unnecessary as all tasks are also added to the taskExecutionOrder
 		return Object.prototype.hasOwnProperty.call(this.tasks, taskName);
 	}
 
@@ -200,21 +202,30 @@ class AbstractBuilder {
 	 * @returns {Promise} Returns promise chain with tasks
 	 */
 	build(tasksToRun) {
-		const allTasksCount = tasksToRun.filter((value) => this.hasTask(value)).length;
-		this.taskLog.addWork(allTasksCount);
+		const allTasks = this.taskExecutionOrder.filter((taskName) => {
+			// There might be a numeric suffix in case a custom task is configured multiple times.
+			// The suffix needs to be removed in order to check against the list of tasks to run.
+			//
+			// Note: The 'tasksToRun' parameter only allows to specify the custom task name
+			// (without suffix), so it executes either all or nothing.
+			// It's currently not possible to just execute some occurrences of a custom task.
+			// This would require a more robust contract to identify task executions
+			// (e.g. via an 'id' that can be assigned to a specific execution in the configuration).
+			const taskWithoutSuffixCounter = taskName.replace(/--\d+$/, "");
+			return this.hasTask(taskName) && tasksToRun.includes(taskWithoutSuffixCounter);
+		});
 
-		let taskChain = Promise.resolve();
-		for (let i = 0; i < this.taskExecutionOrder.length; i++) {
-			const taskName = this.taskExecutionOrder[i];
-			if (this.hasTask(taskName) && tasksToRun.includes(taskName)) {
-				const taskFunction = this.tasks[taskName];
+		this.taskLog.addWork(allTasks.length);
 
-				if (typeof taskFunction === "function") {
-					taskChain = taskChain.then(this.wrapTask(taskName, taskFunction));
-				}
+		return allTasks.reduce((taskChain, taskName) => {
+			const taskFunction = this.tasks[taskName];
+
+			if (typeof taskFunction === "function") {
+				taskChain = taskChain.then(this.wrapTask(taskName, taskFunction));
 			}
-		}
-		return taskChain;
+
+			return taskChain;
+		}, Promise.resolve());
 	}
 
 	/**

test/lib/types/AbstractBuilder.js

@@ -303,6 +303,56 @@ test.serial("Instantiation with custom task defined three times", (t) => {
 		"Order of tasks is correct");
 });
 
+test.serial("Instantiation with custom task defined three times: Custom tasks get called correctly", async (t) => {
+	const customTaskStub = sinon.stub().returns(Promise.resolve());
+	sinon.stub(taskRepository, "getTask").returns({
+		task: customTaskStub,
+		specVersion: "2.0"
+	});
+
+	const project = clone(applicationBTree);
+	project.builder = {
+		customTasks: [{
+			name: "myTask",
+			beforeTask: "myStandardTask",
+			configuration: "foo"
+		}, {
+			name: "myTask",
+			afterTask: "replaceVersion",
+			configuration: "bar"
+		}, {
+			name: "myTask",
+			beforeTask: "myStandardTask",
+			configuration: "baz"
+		}]
+	};
+
+	const resourceCollections = {
+		workspace: "myWorkspace",
+		dependencies: "myDependencies"
+	};
+	const getInterfaceStub = sinon.stub().returns(undefined);
+	const taskUtil = {
+		getInterface: getInterfaceStub
+	};
+	const customBuilder = new CustomBuilder({project, resourceCollections, taskUtil});
+	await customBuilder.build(["myTask"]);
+
+	t.is(getInterfaceStub.callCount, 3, "taskUtil.getInterface got called three times");
+	t.is(customTaskStub.callCount, 3, "Custom task got called three times");
+	["foo", "baz", "bar"].forEach((configuration, index) => {
+		t.deepEqual(customTaskStub.getCall(index).args[0], {
+			options: {
+				projectName: "application.b",
+				projectNamespace: "application/b",
+				configuration
+			},
+			workspace: "myWorkspace",
+			dependencies: "myDependencies"
+		}, `Custom task invocation ${index} got called with expected options`);
+	});
+});
+
 test.serial("Instantiation with custom task: Custom task called correctly", (t) => {
 	const customTaskStub = sinon.stub();
 	sinon.stub(taskRepository, "getTask").returns({