Using @Async annotation and WebTestClient

Changed synchronous mail transfer to asynchronous. You also switched to
the WebTest Client without using MockMvc, which is dependent on Spring
ApplicationContext. As a result, the test runs 60% faster.

build.gradle

@@ -45,9 +45,11 @@ dependencies {
     implementation 'org.springframework.security:spring-security-crypto:5.5.2'
     implementation 'org.springframework.boot:spring-boot-starter-validation'
     implementation 'org.springframework.boot:spring-boot-starter-web'
+    implementation 'org.springframework.boot:spring-boot-starter-webflux'
 
     testImplementation 'io.github.javaunit:autoparams:0.2.12'
     testImplementation 'com.tngtech.archunit:archunit-junit5:0.20.1'
+    testImplementation 'org.mockito:mockito-inline:3.9.0'
 
     testImplementation 'org.springframework.boot:spring-boot-starter-test'
     testImplementation 'org.springframework.restdocs:spring-restdocs-mockmvc'

src/main/java/com/yam/app/account/infrastructure/AsyncConfiguration.java

@@ -0,0 +1,28 @@
+package com.yam.app.account.infrastructure;
+
+import java.util.concurrent.Executor;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.scheduling.annotation.AsyncConfigurer;
+import org.springframework.scheduling.annotation.EnableAsync;
+import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;
+
+@Slf4j
+@EnableAsync
+@Configuration
+public class AsyncConfiguration implements AsyncConfigurer {
+
+    @Override
+    public Executor getAsyncExecutor() {
+        var executor = new ThreadPoolTaskExecutor();
+        int processors = Runtime.getRuntime().availableProcessors();
+        log.info("processors count {}", processors);
+        executor.setCorePoolSize(processors);
+        executor.setMaxPoolSize(processors * 2);
+        executor.setQueueCapacity(50);
+        executor.setKeepAliveSeconds(60);
+        executor.setThreadNamePrefix("AsyncExecutor-");
+        executor.initialize();
+        return executor;
+    }
+}

src/main/java/com/yam/app/account/infrastructure/MailManager.java

@@ -3,12 +3,13 @@ package com.yam.app.account.infrastructure;
 import com.yam.app.account.domain.RegisterAccountEvent;
 import org.springframework.beans.factory.annotation.Value;
 import org.springframework.context.event.EventListener;
+import org.springframework.scheduling.annotation.Async;
 import org.springframework.stereotype.Component;
 import org.thymeleaf.TemplateEngine;
 import org.thymeleaf.context.Context;
 
 @Component
-final class MailManager {
+class MailManager {
 
     private final MailDispatcher mailDispatcher;
     private final TemplateEngine templateEngine;
@@ -21,6 +22,7 @@ final class MailManager {
         this.host = host;
     }
 
+    @Async
     @EventListener
     public void handle(RegisterAccountEvent event) {
         var newAccount = event.getAccount();

src/test/java/com/yam/app/CircularDependencyTests.java

@@ -5,10 +5,8 @@ import static com.tngtech.archunit.library.dependencies.SlicesRuleDefinition.sli
 import com.tngtech.archunit.junit.AnalyzeClasses;
 import com.tngtech.archunit.junit.ArchTest;
 import com.tngtech.archunit.lang.ArchRule;
-import org.junit.jupiter.api.Disabled;
 
 @AnalyzeClasses(packagesOf = YouAndMeApplication.class)
-@Disabled
 final class CircularDependencyTests {
 
     @ArchTest

src/test/java/com/yam/app/YouAndMeApplicationTests.java

@@ -0,0 +1,27 @@
+package com.yam.app;
+
+import static org.mockito.Mockito.mockStatic;
+
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+import org.mockito.MockedStatic;
+import org.springframework.boot.SpringApplication;
+
+final class YouAndMeApplicationTests {
+
+    @Test
+    @DisplayName("SpringApplication.run() 실행을 Mocking합니다.")
+    void mainShouldStartMyApplication() {
+        try (MockedStatic<SpringApplication> mocked = mockStatic(SpringApplication.class)) {
+
+            mocked.when(
+                    () -> SpringApplication.run(YouAndMeApplication.class, "foo"))
+                .thenReturn(null);
+
+            YouAndMeApplication.main(new String[]{"foo"});
+
+            mocked.verify(
+                () -> SpringApplication.run(YouAndMeApplication.class, "foo"));
+        }
+    }
+}

src/test/java/com/yam/app/account/integration/AccountIntegrationTests.java

@@ -1,12 +1,8 @@
 package com.yam.app.account.integration;
 
-import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.post;
-import static org.springframework.test.web.servlet.result.MockMvcResultHandlers.print;
-import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.jsonPath;
-import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
-
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.yam.app.account.presentation.RegisterAccountRequest;
+import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.DisplayName;
 import org.junit.jupiter.api.Test;
 import org.springframework.beans.factory.annotation.Autowired;
@@ -14,7 +10,9 @@ import org.springframework.boot.test.autoconfigure.web.servlet.AutoConfigureMock
 import org.springframework.boot.test.context.SpringBootTest;
 import org.springframework.http.MediaType;
 import org.springframework.test.context.ActiveProfiles;
+import org.springframework.test.web.reactive.server.WebTestClient;
 import org.springframework.test.web.servlet.MockMvc;
+import org.springframework.test.web.servlet.client.MockMvcWebTestClient;
 
 @SpringBootTest
 @AutoConfigureMockMvc
@@ -28,6 +26,15 @@ final class AccountIntegrationTests {
     @Autowired
     private ObjectMapper objectMapper;
 
+    private WebTestClient webTestClient;
+
+    @BeforeEach
+    void setUp() {
+        this.webTestClient = MockMvcWebTestClient
+            .bindTo(mockMvc)
+            .build();
+    }
+
     @Test
     @DisplayName("새로운 계정을 등록하는 회원가입 시나리오")
     void register_success() throws Exception {
@@ -38,18 +45,20 @@ final class AccountIntegrationTests {
         request.setPassword("password!");
 
         // Act
-        final var actions = mockMvc.perform(post("/api/accounts")
+        var spec = webTestClient
+            .post()
+            .uri("/api/accounts")
             .accept(MediaType.APPLICATION_JSON)
             .contentType(MediaType.APPLICATION_JSON)
-            .content(objectMapper.writeValueAsString(request))
-        );
+            .bodyValue(objectMapper.writeValueAsString(request))
+            .exchange();
 
         // Assert
-        actions
-            .andDo(print())
-            .andExpect(status().isOk())
-            .andExpect(jsonPath("$.id").isNumber())
-            .andExpect(jsonPath("$.email").isString())
-            .andExpect(jsonPath("$.nickname").isString());
+        spec
+            .expectStatus().isOk()
+            .expectBody()
+            .jsonPath("$.id").isNumber()
+            .jsonPath("$.email").isNotEmpty()
+            .jsonPath("$.nickname").isNotEmpty();
     }
 }

src/test/java/com/yam/app/account/presentation/RegisterAccountApiTests.java

@@ -1,14 +1,11 @@
 package com.yam.app.account.presentation;
 
 import static org.mockito.Mockito.when;
-import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.post;
-import static org.springframework.test.web.servlet.result.MockMvcResultHandlers.print;
-import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.jsonPath;
-import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
 
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.yam.app.account.application.AccountFacade;
 import org.javaunit.autoparams.AutoSource;
+import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.DisplayName;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.params.ParameterizedTest;
@@ -16,8 +13,11 @@ import org.junit.jupiter.params.provider.NullAndEmptySource;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.test.autoconfigure.web.servlet.WebMvcTest;
 import org.springframework.boot.test.mock.mockito.MockBean;
+import org.springframework.http.HttpStatus;
 import org.springframework.http.MediaType;
+import org.springframework.test.web.reactive.server.WebTestClient;
 import org.springframework.test.web.servlet.MockMvc;
+import org.springframework.test.web.servlet.client.MockMvcWebTestClient;
 
 @DisplayName("회원가입 등록 HTTP API")
 @WebMvcTest(RegisterAccountApi.class)
@@ -30,6 +30,15 @@ class RegisterAccountApiTests {
     @MockBean
     private AccountFacade accountFacade;
 
+    private WebTestClient webTestClient;
+
+    @BeforeEach
+    void setUp() {
+        this.webTestClient = MockMvcWebTestClient
+            .bindTo(mockMvc)
+            .build();
+    }
+
     @Test
     @DisplayName("회원가입에 적절한 파라미터가 입력되고 회원가입이 성공한다.")
     void register_success() throws Exception {
@@ -43,19 +52,21 @@ class RegisterAccountApiTests {
         when(accountFacade.register(request)).thenReturn(
             new AccountResponse(1L, "msolo021015@gmail.com", "rebwon"));
 
-        final var actions = mockMvc.perform(post("/api/accounts")
+        var spec = webTestClient
+            .post()
+            .uri("/api/accounts")
             .accept(MediaType.APPLICATION_JSON)
             .contentType(MediaType.APPLICATION_JSON)
-            .content(objectMapper.writeValueAsString(request))
-        );
+            .bodyValue(objectMapper.writeValueAsString(request))
+            .exchange();
 
         // Assert
-        actions
-            .andDo(print())
-            .andExpect(status().isOk())
-            .andExpect(jsonPath("$.id").isNumber())
-            .andExpect(jsonPath("$.email").isString())
-            .andExpect(jsonPath("$.nickname").isString());
+        spec
+            .expectStatus().isOk()
+            .expectBody()
+            .jsonPath("$.id").isNumber()
+            .jsonPath("$.email").isNotEmpty()
+            .jsonPath("$.nickname").isNotEmpty();
     }
 
     @Test
@@ -68,13 +79,15 @@ class RegisterAccountApiTests {
         request.setPassword("password!");
 
         // Act
-        final var actions = mockMvc.perform(post("/api/accounts")
-            .content(objectMapper.writeValueAsString(request))
-        );
+        var spec = webTestClient
+            .post()
+            .uri("/api/accounts")
+            .bodyValue(objectMapper.writeValueAsString(request))
+            .exchange();
 
         // Assert
-        actions
-            .andExpect(status().isUnsupportedMediaType());
+        spec
+            .expectStatus().isEqualTo(HttpStatus.UNSUPPORTED_MEDIA_TYPE);
     }
 
     @ParameterizedTest
@@ -88,16 +101,17 @@ class RegisterAccountApiTests {
         request.setPassword(arg);
 
         // Act
-        final var actions = mockMvc.perform(post("/api/accounts")
+        var spec = webTestClient
+            .post()
+            .uri("/api/accounts")
             .accept(MediaType.APPLICATION_JSON)
             .contentType(MediaType.APPLICATION_JSON)
-            .content(objectMapper.writeValueAsString(request))
-        );
+            .bodyValue(objectMapper.writeValueAsString(request))
+            .exchange();
 
         // Assert
-        actions
-            .andDo(print())
-            .andExpect(status().isBadRequest());
+        spec
+            .expectStatus().isBadRequest();
     }
 
     @ParameterizedTest
@@ -111,15 +125,16 @@ class RegisterAccountApiTests {
         request.setPassword(arg);
 
         // Act
-        final var actions = mockMvc.perform(post("/api/accounts")
+        var spec = webTestClient
+            .post()
+            .uri("/api/accounts")
             .accept(MediaType.APPLICATION_JSON)
             .contentType(MediaType.APPLICATION_JSON)
-            .content(objectMapper.writeValueAsString(request))
-        );
+            .bodyValue(objectMapper.writeValueAsString(request))
+            .exchange();
 
         // Assert
-        actions
-            .andDo(print())
-            .andExpect(status().isBadRequest());
+        spec
+            .expectStatus().isBadRequest();
     }
 }