The best way to test Spring application context is to use ApplicationContextRunner
It is described in Spring Boot Reference Documentation:
https://docs.spring.io/spring-boot/docs/current/reference/html/boot-features-developing-auto-configuration.html#boot-features-test-autoconfig
And there is a quick guide about it:
https://www.baeldung.com/spring-boot-context-runner
Sample usage
private static final String POSITIVE_CASE_CONFIG_FILE =
"classpath:some/path/positive-case-config.yml";
private static final String NEGATIVE_CASE_CONFIG_FILE =
"classpath:some/path/negative-case-config.yml";
@Test
void positiveTest() {
ApplicationContextRunner contextRunner = new ApplicationContextRunner()
.withInitializer(new ConfigDataApplicationContextInitializer())//1
.withInitializer(new ConditionEvaluationReportLoggingListener(LogLevel.DEBUG))//2
.withUserConfiguration(MockBeansTestConfiguration.class)//3
.withPropertyValues("spring.config.location=" + POSITIVE_CASE_CONFIG_FILE)//4
.withConfiguration(AutoConfigurations.of(BookService.class));//5
contextRunner
.run((context) -> {
Assertions.assertThat(context).hasNotFailed();//6
});
}
@Test
void negativeTest() {
ApplicationContextRunner contextRunner = new ApplicationContextRunner()
.withInitializer(new ConfigDataApplicationContextInitializer())//1
.withInitializer(new ConditionEvaluationReportLoggingListener(LogLevel.DEBUG))//2
.withUserConfiguration(MockBeansTestConfiguration.class)//3
.withPropertyValues("spring.config.location=" + NEGATIVE_CASE_CONFIG_FILE)//4
.withConfiguration(AutoConfigurations.of(BookService.class));//5
contextRunner
.run((context) -> {
assertThat(context)
.hasFailed();
assertThat(context.getStartupFailure())
.isNotNull();
assertThat(context.getStartupFailure().getMessage())
.contains("Some exception message");
assertThat(extractFailureCauseMessages(context))
.contains("Cause exception message");
});
}
private List<String> extractFailureCauseMessages(AssertableApplicationContext context) {
var failureCauseMessages = new ArrayList<String>();
var currentCause = context.getStartupFailure().getCause();
while (!Objects.isNull(currentCause)) {//7
failureCauseMessages.add(currentCause.getMessage());
currentCause = currentCause.getCause();
}
return failureCauseMessages;
}
Explanation with examples of similar definitions from Junit5 Spring Boot Test Annotations:
- Triggers loading of config files like
application.properties or application.yml
- Logs
ConditionEvaluationReport using given log level when application context fails
- Provides class that specifies mock beans, ie. we have
@Autowired BookRepository in our BookService and we provide mock BookRepository in MockBeansTestConfiguration. Similar to @Import({MockBeansTestConfiguration.class}) in test class and @TestConfiguration in class with mock beans in normal Junit5 Spring Boot Test
- Equivalent of
@TestPropertySource(properties = { "spring.config.location=" + POSITIVE_CASE_CONFIG_FILE})
- Triggers spring auto configuration for given class, not direct equivalent, but it is similar to using
@ContextConfiguration(classes = {BookService.class}) or @SpringBootTest(classes = {BookService.class}) together with @Import({BookService.class}) in normal test
- Assertions.class from AssertJ library, there should be static import for
Assertions.assertThat, but I wanted to show where this method is from
- There should be static import for
Objects.isNull, but I wanted to show where this method is from
MockBeansTestConfiguration class:
@TestConfiguration
public class MockBeansTestConfiguration {
private static final Book SAMPLE_BOOK = Book.of(1L, "Stanisław Lem", "Solaris", "978-3-16-148410-0");
@Bean
public BookRepository mockBookRepository() {
var bookRepository = Mockito.mock(BookRepository.class);//1
Mockito.when(bookRepository.findByIsbn(SAMPLE_BOOK.getIsbn()))//2
.thenReturn(SAMPLE_BOOK);
return bookRepository;
}
}
Remarks:
1,2. There should be static import, but I wanted to show where this method is from
