feat: Idempotent Consumer Microservice Pattern #2683 (#3082)

* added idempotent consumer pattern * updated doc * fixed bug in RequestService * add test converage * Add test converage to state machine * renamed module and added code example
2026-05-21 08:24:40 +00:00 · 2024-11-11 16:59:35 +01:00
parent 25bb77eee7
commit 2a2c5605bc
13 changed files with 930 additions and 0 deletions
@@ -0,0 +1,46 @@
+package com.iluwatar.idempotentconsumer;
+
+import org.junit.jupiter.api.Test;
+import org.mockito.Mockito;
+import org.springframework.boot.CommandLineRunner;
+
+import java.util.UUID;
+
+import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+/**
+ * Application test
+ */
+class AppTest {
+
+  @Test
+  void main() {
+    assertDoesNotThrow(() -> App.main(new String[] {}));
+  }
+
+  @Test
+  void run() throws Exception {
+    RequestService requestService = Mockito.mock(RequestService.class);
+    RequestRepository requestRepository = Mockito.mock(RequestRepository.class);
+    UUID uuid = UUID.randomUUID();
+    Request requestPending = new Request(uuid);
+    Request requestStarted = new Request(uuid, Request.Status.STARTED);
+    Request requestCompleted = new Request(uuid, Request.Status.COMPLETED);
+    when(requestService.create(any())).thenReturn(requestPending);
+    when(requestService.start(any())).thenReturn(requestStarted);
+    when(requestService.complete(any())).thenReturn(requestCompleted);
+
+    CommandLineRunner runner = new App().run(requestService, requestRepository);
+
+    runner.run();
+
+    verify(requestService, times(3)).create(any());
+    verify(requestService, times(2)).start(any());
+    verify(requestService, times(1)).complete(any());
+    verify(requestRepository, times(1)).count();
+  }
+}
@@ -0,0 +1,135 @@
+/*
+ * This project is licensed under the MIT license. Module model-view-viewmodel is using ZK framework licensed under LGPL (see lgpl-3.0.txt).
+ *
+ * The MIT License
+ * Copyright © 2014-2022 Ilkka Seppälä
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+package com.iluwatar.idempotentconsumer;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+import java.util.Optional;
+import java.util.UUID;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.Mock;
+import org.mockito.junit.jupiter.MockitoExtension;
+
+@ExtendWith(MockitoExtension.class)
+class RequestServiceTests {
+  private RequestService requestService;
+  @Mock
+  private RequestRepository requestRepository;
+  private RequestStateMachine requestStateMachine;
+  @BeforeEach
+  void setUp() {
+    requestStateMachine = new RequestStateMachine();
+    requestService = new RequestService(requestRepository, requestStateMachine);
+  }
+
+  @Test
+  void createRequest_whenNotExists() {
+    UUID uuid = UUID.randomUUID();
+    Request request = new Request(uuid);
+    when(requestRepository.findById(any())).thenReturn(Optional.empty());
+    when(requestRepository.save(request)).thenReturn(request);
+    assertEquals(request, requestService.create(uuid));
+    verify(requestRepository, times(1)).findById(uuid);
+    verify(requestRepository, times(1)).save(any());
+  }
+  @Test
+  void createRequest_whenExists() {
+    UUID uuid = UUID.randomUUID();
+    Request request = new Request(uuid);
+    when(requestRepository.findById(any())).thenReturn(Optional.of(request));
+    assertEquals(request, requestService.create(uuid));
+    verify(requestRepository, times(1)).findById(uuid);
+    verify(requestRepository, times(0)).save(any());
+  }
+
+  @Test
+  void startRequest_whenNotExists_shouldThrowError() {
+    UUID uuid = UUID.randomUUID();
+    when(requestRepository.findById(any())).thenReturn(Optional.empty());
+    assertThrows(RequestNotFoundException.class, ()->requestService.start(uuid));
+    verify(requestRepository, times(1)).findById(uuid);
+    verify(requestRepository, times(0)).save(any());
+  }
+
+  @Test
+  void startRequest_whenIsPending() {
+    UUID uuid = UUID.randomUUID();
+    Request request = new Request(uuid);
+    Request startedEntity = new Request(uuid, Request.Status.STARTED);
+    when(requestRepository.findById(any())).thenReturn(Optional.of(request));
+    when(requestRepository.save(any())).thenReturn(startedEntity);
+    assertEquals(startedEntity, requestService.start(uuid));
+    verify(requestRepository, times(1)).findById(uuid);
+    verify(requestRepository, times(1)).save(startedEntity);
+  }
+
+  @Test
+  void startRequest_whenIsStarted_shouldThrowError() {
+    UUID uuid = UUID.randomUUID();
+    Request requestStarted = new Request(uuid, Request.Status.STARTED);
+    when(requestRepository.findById(any())).thenReturn(Optional.of(requestStarted));
+    assertThrows(InvalidNextStateException.class, ()->requestService.start(uuid));
+    verify(requestRepository, times(1)).findById(uuid);
+    verify(requestRepository, times(0)).save(any());
+  }
+
+  @Test
+  void startRequest_whenIsCompleted_shouldThrowError() {
+    UUID uuid = UUID.randomUUID();
+    Request requestStarted = new Request(uuid, Request.Status.COMPLETED);
+    when(requestRepository.findById(any())).thenReturn(Optional.of(requestStarted));
+    assertThrows(InvalidNextStateException.class, ()->requestService.start(uuid));
+    verify(requestRepository, times(1)).findById(uuid);
+    verify(requestRepository, times(0)).save(any());
+  }
+
+  @Test
+  void completeRequest_whenStarted() {
+    UUID uuid = UUID.randomUUID();
+    Request request = new Request(uuid, Request.Status.STARTED);
+    Request completedEntity = new Request(uuid, Request.Status.COMPLETED);
+    when(requestRepository.findById(any())).thenReturn(Optional.of(request));
+    when(requestRepository.save(any())).thenReturn(completedEntity);
+    assertEquals(completedEntity, requestService.complete(uuid));
+    verify(requestRepository, times(1)).findById(uuid);
+    verify(requestRepository, times(1)).save(completedEntity);
+  }
+  @Test
+  void completeRequest_whenNotInprogress() {
+    UUID uuid = UUID.randomUUID();
+    Request request = new Request(uuid);
+    when(requestRepository.findById(any())).thenReturn(Optional.of(request));
+    assertThrows(InvalidNextStateException.class, () -> requestService.complete(uuid));
+    verify(requestRepository, times(1)).findById(uuid);
+    verify(requestRepository, times(0)).save(any());
+  }
+}
@@ -0,0 +1,59 @@
+package com.iluwatar.idempotentconsumer;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import java.util.UUID;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+class RequestStateMachineTests {
+  private RequestStateMachine requestStateMachine;
+
+  @BeforeEach
+  public void setUp() {
+    requestStateMachine = new RequestStateMachine();
+  }
+
+  @Test
+  void transitionPendingToStarted() {
+    Request startedRequest = requestStateMachine.next(new Request(UUID.randomUUID(), Request.Status.PENDING),
+        Request.Status.STARTED);
+    assertEquals(Request.Status.STARTED, startedRequest.getStatus());
+  }
+
+  @Test
+  void transitionAnyToPending_shouldThrowError() {
+    assertThrows(InvalidNextStateException.class,
+        () -> requestStateMachine.next(new Request(UUID.randomUUID(), Request.Status.PENDING),
+            Request.Status.PENDING));
+    assertThrows(InvalidNextStateException.class,
+        () -> requestStateMachine.next(new Request(UUID.randomUUID(), Request.Status.STARTED),
+            Request.Status.PENDING));
+    assertThrows(InvalidNextStateException.class,
+        () -> requestStateMachine.next(new Request(UUID.randomUUID(), Request.Status.COMPLETED),
+            Request.Status.PENDING));
+  }
+
+  @Test
+  void transitionCompletedToAny_shouldThrowError() {
+    assertThrows(InvalidNextStateException.class,
+        () -> requestStateMachine.next(new Request(UUID.randomUUID(), Request.Status.COMPLETED),
+            Request.Status.PENDING));
+    assertThrows(InvalidNextStateException.class,
+        () -> requestStateMachine.next(new Request(UUID.randomUUID(), Request.Status.COMPLETED),
+            Request.Status.STARTED));
+    assertThrows(InvalidNextStateException.class,
+        () -> requestStateMachine.next(new Request(UUID.randomUUID(), Request.Status.COMPLETED),
+            Request.Status.COMPLETED));
+  }
+
+  @Test
+  void transitionStartedToCompleted() {
+    Request completedRequest = requestStateMachine.next(new Request(UUID.randomUUID(), Request.Status.STARTED),
+        Request.Status.COMPLETED);
+    assertEquals(Request.Status.COMPLETED, completedRequest.getStatus());
+  }
+
+
+}