Spring Boot TDD Workflow Skill

Spring Boot TDD Workflow

TDD guidance for Spring Boot services with 80%+ coverage (unit + integration).

Maestro Integration

Lifecycle: implement Activates when: maestro:new-track detects relevant tech in tech-stack.md, or maestro:implement encounters matching task types.

Phase Guidance

In maestro:implement: Apply during Red phase (Step 6a.2) for Spring tests. Use MockMvc for controller tests, Mockito for service mocking, Testcontainers for integration tests.

Related Skills

maestro:springboot-patterns
maestro:jpa-patterns
maestro:tdd-workflow

Workflow

Write tests first (they should fail)
Implement minimal code to pass
Refactor with tests green
Enforce coverage (JaCoCo)

Unit Tests (JUnit 5 + Mockito)

@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)

@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)

@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)

@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:

<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

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.

Relationship to Maestro Workflow

/maestro:new-track -- Detects this skill during Step 9.5 (skill matching)
/maestro:implement -- Loads this skill's guidance during task execution
/maestro:review -- Uses checklists as review criteria

Agent Skills: Spring Boot TDD Workflow

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Skill Files