Adding source files for the tutorial BAEL-2788 (#6699)

* Adding source files for the tutorial BAEL-2788

* Made changes to the code for the review comments

spring-boot-flowable/src/test/java/com/baeldung/processes/ArticleWorkflowUnitTest.java

@@ -0,0 +1,40 @@
+package com.baeldung.processes;
+
+import static org.junit.Assert.assertEquals;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import org.flowable.engine.RuntimeService;
+import org.flowable.engine.TaskService;
+import org.flowable.engine.test.Deployment;
+import org.flowable.spring.impl.test.FlowableSpringExtension;
+import org.flowable.task.api.Task;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.test.context.junit.jupiter.SpringExtension;
+
+@ExtendWith(FlowableSpringExtension.class)
+@ExtendWith(SpringExtension.class)
+public class ArticleWorkflowUnitTest {
+    @Autowired
+    private RuntimeService runtimeService;
+    @Autowired
+    private TaskService taskService;
+    @Test
+    @Deployment(resources = { "processes/article-workflow.bpmn20.xml" })
+    void articleApprovalTest() {
+        Map<String, Object> variables = new HashMap<String, Object>();
+        variables.put("author", "test@baeldung.com");
+        variables.put("url", "http://baeldung.com/dummy");
+        runtimeService.startProcessInstanceByKey("articleReview", variables);
+        Task task = taskService.createTaskQuery()
+            .singleResult();
+        assertEquals("Review the submitted tutorial", task.getName());
+        variables.put("approved", true);
+        taskService.complete(task.getId(), variables);
+        assertEquals(0, runtimeService.createProcessInstanceQuery()
+            .count());
+    }
+}