mirror of https://github.com/github/awesome-copilot.git synced 2026-03-20 16:15:12 +00:00

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Kartik Dhiman e4fc57f204 feat: add spring-boot-testing skill for Spring Boot 4.0 (#1085 )

- Introduced MockMvcTester for AssertJ-style assertions in Spring MVC testing.
- Added @RestClientTest for testing REST clients with MockRestServiceServer.
- Implemented RestTestClient as a modern alternative to TestRestTemplate.
- Documented migration steps from Spring Boot 3.x to 4.0, including dependency and annotation changes.
- Created an overview of test slices to guide testing strategies.
- Included Testcontainers setup for JDBC testing with PostgreSQL and MySQL.
- Enhanced @WebMvcTest documentation with examples for various HTTP methods and validation.

2026-03-20 10:24:37 +11:00

4.6 KiB

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@RestClientTest

Testing REST clients in isolation with MockRestServiceServer.

Overview

@RestClientTest auto-configures:

RestTemplate/RestClient with mock server support
Jackson ObjectMapper
MockRestServiceServer

Basic Setup

@RestClientTest(WeatherService.class)
class WeatherServiceTest {
  
  @Autowired
  private WeatherService weatherService;
  
  @Autowired
  private MockRestServiceServer server;
}

Testing RestTemplate

@RestClientTest(WeatherService.class)
class WeatherServiceTest {
  
  @Autowired
  private WeatherService weatherService;
  
  @Autowired
  private MockRestServiceServer server;
  
  @Test
  void shouldFetchWeather() {
    // Given
    server.expect(requestTo("https://api.weather.com/v1/current"))
      .andExpect(method(HttpMethod.GET))
      .andExpect(queryParam("city", "Berlin"))
      .andRespond(withSuccess()
        .contentType(MediaType.APPLICATION_JSON)
        .body("{\"temperature\": 22, \"condition\": \"Sunny\"}"));
    
    // When
    Weather weather = weatherService.getCurrentWeather("Berlin");
    
    // Then
    assertThat(weather.getTemperature()).isEqualTo(22);
    assertThat(weather.getCondition()).isEqualTo("Sunny");
  }
}

Testing RestClient (Spring 6.1+)

@RestClientTest(WeatherService.class)
class WeatherServiceTest {
  
  @Autowired
  private WeatherService weatherService;
  
  @Autowired
  private MockRestServiceServer server;
  
  @Test
  void shouldFetchWeatherWithRestClient() {
    server.expect(requestTo("https://api.weather.com/v1/current"))
      .andRespond(withSuccess()
        .body("{\"temperature\": 22}"));
    
    Weather weather = weatherService.getCurrentWeather("Berlin");
    
    assertThat(weather.getTemperature()).isEqualTo(22);
  }
}

Request Matching

Exact URL

server.expect(requestTo("https://api.example.com/users/1"))
  .andRespond(withSuccess());

URL Pattern

server.expect(requestTo(matchesPattern("https://api.example.com/users/\\d+")))
  .andRespond(withSuccess());

HTTP Method

server.expect(ExpectedCount.once(), 
  requestTo("https://api.example.com/users"))
  .andExpect(method(HttpMethod.POST))
  .andRespond(withCreatedEntity(URI.create("/users/1")));

Request Body

server.expect(requestTo("https://api.example.com/users"))
  .andExpect(content().contentType(MediaType.APPLICATION_JSON))
  .andExpect(content().json("{\"name\": \"John\"}"))
  .andRespond(withSuccess());

Headers

server.expect(requestTo("https://api.example.com/users"))
  .andExpect(header("Authorization", "Bearer token123"))
  .andExpect(header("X-Api-Key", "secret"))
  .andRespond(withSuccess());

Response Types

Success with Body

server.expect(requestTo("/users/1"))
  .andRespond(withSuccess()
    .contentType(MediaType.APPLICATION_JSON)
    .body("{\"id\": 1, \"name\": \"John\"}"));

Success from Resource

server.expect(requestTo("/users/1"))
  .andRespond(withSuccess()
    .body(new ClassPathResource("user-response.json")));

Created

server.expect(requestTo("/users"))
  .andExpect(method(HttpMethod.POST))
  .andRespond(withCreatedEntity(URI.create("/users/1")));

Error Response

server.expect(requestTo("/users/999"))
  .andRespond(withResourceNotFound());

server.expect(requestTo("/users"))
  .andRespond(withServerError()
    .body("Internal Server Error"));

server.expect(requestTo("/users"))
  .andRespond(withStatus(HttpStatus.BAD_REQUEST)
    .body("{\"error\": \"Invalid input\"}"));

Verifying Requests

@Test
void shouldCallApi() {
  server.expect(ExpectedCount.once(), 
    requestTo("https://api.example.com/data"))
    .andRespond(withSuccess());
  
  service.fetchData();
  
  server.verify(); // Verify all expectations met
}

Ignoring Extra Requests

@Test
void shouldHandleMultipleCalls() {
  server.expect(ExpectedCount.manyTimes(),
    requestTo(matchesPattern("/api/.*")))
    .andRespond(withSuccess());
  
  // Multiple calls allowed
  service.callApi();
  service.callApi();
  service.callApi();
}

Reset Between Tests

@BeforeEach
void setUp() {
  server.reset();
}

Testing Timeouts

server.expect(requestTo("/slow-endpoint"))
  .andRespond(withSuccess()
    .body("{\"data\": \"test\"}")
    .delay(100, TimeUnit.MILLISECONDS));

// Test timeout handling

Best Practices

Always verify server.verify() at end of test
Use resource files for large JSON responses
Match on minimal set of request attributes
Reset server in @BeforeEach
Test error responses, not just success
Verify request body for POST/PUT calls

4.6 KiB Raw Blame History