springboot-tdd
用 JUnit 5、Mockito、MockMvc 和 Testcontainers 做 Spring Boot TDD
中文翻譯
---
name: springboot-tdd
description: 用 JUnit 5、Mockito、MockMvc、Testcontainers 和 JaCoCo，對 Spring Boot 做測試驅動開發。新增功能、修 bug 或重構時使用。
metadata:
origin: ECC
---
# Spring Boot TDD 工作流程
Spring Boot 服務的 TDD 指引，目標 80% 以上的覆蓋率（單元 + 整合）。
## 何時使用
- 新功能或 endpoint
- 修 bug 或重構
- 新增資料存取邏輯或安全規則
## 工作流程
1) 先寫測試（應該要失敗）
2) 實作最少的程式碼讓測試通過
3) 在測試維持綠燈的前提下重構
4) 落實覆蓋率（JaCoCo）
## 單元測試（JUnit 5 + Mockito）
```java
@ExtendWith(MockitoExtension.class)
class MarketServiceTest {
@Mock MarketRepository repo;
@InjectMocks MarketService service;
@Test
void createsMarket() {
CreateMarketRequest req = new CreateMarketRequest("name", "desc", Instant.now(), List.of("cat"));
when(repo.save(any())).thenAnswer(inv -> inv.getArgument(0));
Market result = service.create(req);
assertThat(result.name()).isEqualTo("name");
verify(repo).save(any());
}
}
```
模式：
- Arrange-Act-Assert
- 避免 partial mock；優先用明確的 stub
- 各種變體用 `@ParameterizedTest`
## Web 層測試（MockMvc）
```java
@WebMvcTest(MarketController.class)
class MarketControllerTest {
@Autowired MockMvc mockMvc;
@MockBean MarketService marketService;
@Test
void returnsMarkets() throws Exception {
when(marketService.list(any())).thenReturn(Page.empty());
mockMvc.perform(get("/api/markets"))
.andExpect(status().isOk())
.andExpect(jsonPath("$.content").isArray());
}
}
```
## 整合測試（SpringBootTest）
```java
@SpringBootTest
@AutoConfigureMockMvc
@ActiveProfiles("test")
class MarketIntegrationTest {
@Autowired MockMvc mockMvc;
@Test
void createsMarket() throws Exception {
mockMvc.perform(post("/api/markets")
.contentType(MediaType.APPLICATION_JSON)
.content("""
{"name":"Test","description":"Desc","endDate":"2030-01-01T00:00:00Z","categories":["general"]}
"""))
.andExpect(status().isCreated());
}
}
```
## 持久層測試（DataJpaTest）
```java
@DataJpaTest
@AutoConfigureTestDatabase(replace = AutoConfigureTestDatabase.Replace.NONE)
@Import(TestContainersConfig.class)
class MarketRepositoryTest {
@Autowired MarketRepository repo;
@Test
void savesAndFinds() {
MarketEntity entity = new MarketEntity();
entity.setName("Test");
repo.save(entity);
Optional<MarketEntity> found = repo.findByName("Test");
assertThat(found).isPresent();
}
}
```
## Testcontainers
- Postgres/Redis 用可重複使用的容器，貼近正式環境
- 透過 `@DynamicPropertySource` 把 JDBC URL 注入 Spring context
## 覆蓋率（JaCoCo）
Maven 片段：
```xml
<plugin>
<groupId>org.jacoco</groupId>
<artifactId>jacoco-maven-plugin</artifactId>
<version>0.8.14</version>
<executions>
<execution>
<goals><goal>prepare-agent</goal></goals>
</execution>
<execution>
<id>report</id>
<phase>verify</phase>
<goals><goal>report</goal></goals>
</execution>
</executions>
</plugin>
```
## 斷言
- 為了可讀性，優先用 AssertJ（`assertThat`）
- JSON 回應用 `jsonPath`
- 例外用：`assertThatThrownBy(...)`
## 測試資料 Builder
```java
class MarketBuilder {
private String name = "Test";
MarketBuilder withName(String name) { this.name = name; return this; }
Market build() { return new Market(null, name, MarketStatus.ACTIVE); }
}
```
## CI 指令
- Maven：`mvn -T 4 test` 或 `mvn verify`
- Gradle：`./gradlew test jacocoTestReport`
**記住**：測試要快、要隔離、要可預測。測行為，不要測實作細節。英文原文
---
name: springboot-tdd
description: Test-driven development for Spring Boot using JUnit 5, Mockito, MockMvc, Testcontainers, and JaCoCo. Use when adding features, fixing bugs, or refactoring.
metadata:
origin: ECC
---
# Spring Boot TDD Workflow
TDD guidance for Spring Boot services with 80%+ coverage (unit + integration).
## When to Use
- New features or endpoints
- Bug fixes or refactors
- Adding data access logic or security rules
## Workflow
1) Write tests first (they should fail)
2) Implement minimal code to pass
3) Refactor with tests green
4) Enforce coverage (JaCoCo)
## Unit Tests (JUnit 5 + Mockito)
```java
@ExtendWith(MockitoExtension.class)
class MarketServiceTest {
@Mock MarketRepository repo;
@InjectMocks MarketService service;
@Test
void createsMarket() {
CreateMarketRequest req = new CreateMarketRequest("name", "desc", Instant.now(), List.of("cat"));
when(repo.save(any())).thenAnswer(inv -> inv.getArgument(0));
Market result = service.create(req);
assertThat(result.name()).isEqualTo("name");
verify(repo).save(any());
}
}
```
Patterns:
- Arrange-Act-Assert
- Avoid partial mocks; prefer explicit stubbing
- Use `@ParameterizedTest` for variants
## Web Layer Tests (MockMvc)
```java
@WebMvcTest(MarketController.class)
class MarketControllerTest {
@Autowired MockMvc mockMvc;
@MockBean MarketService marketService;
@Test
void returnsMarkets() throws Exception {
when(marketService.list(any())).thenReturn(Page.empty());
mockMvc.perform(get("/api/markets"))
.andExpect(status().isOk())
.andExpect(jsonPath("$.content").isArray());
}
}
```
## Integration Tests (SpringBootTest)
```java
@SpringBootTest
@AutoConfigureMockMvc
@ActiveProfiles("test")
class MarketIntegrationTest {
@Autowired MockMvc mockMvc;
@Test
void createsMarket() throws Exception {
mockMvc.perform(post("/api/markets")
.contentType(MediaType.APPLICATION_JSON)
.content("""
{"name":"Test","description":"Desc","endDate":"2030-01-01T00:00:00Z","categories":["general"]}
"""))
.andExpect(status().isCreated());
}
}
```
## Persistence Tests (DataJpaTest)
```java
@DataJpaTest
@AutoConfigureTestDatabase(replace = AutoConfigureTestDatabase.Replace.NONE)
@Import(TestContainersConfig.class)
class MarketRepositoryTest {
@Autowired MarketRepository repo;
@Test
void savesAndFinds() {
MarketEntity entity = new MarketEntity();
entity.setName("Test");
repo.save(entity);
Optional<MarketEntity> found = repo.findByName("Test");
assertThat(found).isPresent();
}
}
```
## Testcontainers
- Use reusable containers for Postgres/Redis to mirror production
- Wire via `@DynamicPropertySource` to inject JDBC URLs into Spring context
## Coverage (JaCoCo)
Maven snippet:
```xml
<plugin>
<groupId>org.jacoco</groupId>
<artifactId>jacoco-maven-plugin</artifactId>
<version>0.8.14</version>
<executions>
<execution>
<goals><goal>prepare-agent</goal></goals>
</execution>
<execution>
<id>report</id>
<phase>verify</phase>
<goals><goal>report</goal></goals>
</execution>
</executions>
</plugin>
```
## Assertions
- Prefer AssertJ (`assertThat`) for readability
- For JSON responses, use `jsonPath`
- For exceptions: `assertThatThrownBy(...)`
## Test Data Builders
```java
class MarketBuilder {
private String name = "Test";
MarketBuilder withName(String name) { this.name = name; return this; }
Market build() { return new Market(null, name, MarketStatus.ACTIVE); }
}
```
## CI Commands
- Maven: `mvn -T 4 test` or `mvn verify`
- Gradle: `./gradlew test jacocoTestReport`
**Remember**: Keep tests fast, isolated, and deterministic. Test behavior, not implementation details.