Testing the Spring Framework

Guest lecture to first year CS students at TU Delft.

Transcript

1. © Copyright 2019 Pivotal Software, Inc. All rights Reserved.
   Testing the Spring Framework
   Stéphane Nicoll - @snicoll
   

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2. Who am I?
   ● Software Engineer at Pivotal (Spring Boot, Spring
   Framework and start.spring.io)
   ● Involved in open source for 15 years (Apache Maven,
   Spring Framework)
   ● snicoll on the Web (Twitter, Github) - snicoll@pivotal.io
   ● Based in Liège, Belgium (come over, we have waffles)
   

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3. Who am I?
   ● Software Engineer at Pivotal (Spring Boot, Spring
   Framework and start.spring.io)
   ● Involved in open source for 15 years (Apache Maven,
   Spring Framework)
   ● snicoll on the Web (Twitter, Github) - snicoll@pivotal.io
   ● Based in Liège, Belgium (come over, we have waffles)
   

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4. Prerequisite
   “
   

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5. Prerequisite
   “They have a good notion of Java and OOP, know how to use IntelliJ,
   are used to building tools such as Maven and Gradle, and know JUnit
   5 very well.
   Maurício Aniche
   

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6. Prerequisite
   “They have a good notion of Java and OOP, know how to use IntelliJ,
   are used to building tools such as Maven and Gradle, and know JUnit
   5 very well.
   Maurício Aniche
   
   

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7. This is what I was doing during my 1st year
   

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8. This is what I was doing during my 1st year
   

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9. Once upon a time…
   

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10. We stored libs in source control
    
    

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11. We stored libs in source control
    
    

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12. The power of convention over configuration
    

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13. And we had to configure the infrastructure ourselves
    
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:jpa="http://www.springframework.org/schema/data/jpa"
    xmlns:context="http://www.springframework.org/schema/context"
    xsi:schemaLocation="http://www.springframework.org/schema/data/jpa
    https://www.springframework.org/schema/data/jpa/spring-jpa.xsd
    http://www.springframework.org/schema/context
    https://www.springframework.org/schema/context/spring-context.xsd">
    
    
    
    class="org.springframework.jdbc.datasource.DriverManagerDataSource">
    
    
    
    
    
    
    
    
    
    
    
    ${hibernate.dialect}
    ${hibernate.hbm2ddl.auto}
    ${hibernate.show_sql}
    ${hibernate.format_sql}
    
    
    
    
    
    
    
    
    
    

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14. And we had to configure the infrastructure ourselves
    
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:jpa="http://www.springframework.org/schema/data/jpa"
    xmlns:context="http://www.springframework.org/schema/context"
    xsi:schemaLocation="http://www.springframework.org/schema/data/jpa
    https://www.springframework.org/schema/data/jpa/spring-jpa.xsd
    http://www.springframework.org/schema/context
    https://www.springframework.org/schema/context/spring-context.xsd">
    
    
    
    class="org.springframework.jdbc.datasource.DriverManagerDataSource">
    
    
    
    
    
    
    
    
    
    
    
    ${hibernate.dialect}
    ${hibernate.hbm2ddl.auto}
    ${hibernate.show_sql}
    ${hibernate.format_sql}
    
    
    
    
    
    
    
    
    
    
    

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15. And chose which libraries to use (and their versions!)
    
    org.springframework
    spring-context
    ${spring.version}
    
    
    org.springframework
    spring-orm
    ${spring.version}
    
    
    org.springframework.data
    spring-data-jpa
    1.3.0.RELEASE
    
    

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16. And chose which libraries to use (and their versions!)
    
    org.hibernate.javax.persistence
    hibernate-jpa-2.0-api
    1.0.1.Final
    
    
    org.hibernate
    hibernate-entitymanager
    4.1.9.Final
    runtime
    
    
    mysql
    mysql-connector-java
    5.1.6
    runtime
    
    

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17. And chose which libraries to use (and their versions!)
    
    org.hibernate.javax.persistence
    hibernate-jpa-2.0-api
    1.0.1.Final
    
    
    org.hibernate
    hibernate-entitymanager
    4.1.9.Final
    runtime
    
    
    mysql
    mysql-connector-java
    5.1.6
    runtime
    
    
    

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18. The power of convention over configuration
    

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19. Live Coding
    Enough with the slides already!
    

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20. Summary
    ● Conventions can significantly improve your productivity
    ● Best practices for teams and the ecosystem at large
    ● Provide sane defaults when you don’t or shouldn’t care
    ● Make upgrade and maintenance easier
    ● …. but shouldn’t get in your way
    ● Built on top of an API you could use to implement something slightly or totally
    different
    ● Can be customised without having you to redefine everything
    ● Depending on the scope, not everything can be the target of a convention
    

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21. See you in 15
    Break
    

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22. Why bother testing at all?
    

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23. Testing to reduce risk
    Risk
    None
    YOLO
    Tests
    0 Lots
    

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24. Demo
    CI/CD in action on start.spring.io
    

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25. Unit Tests
    

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26. Unit tests should not require any “framework”
    @Service
    public class SubmissionService {
    @Autowired
    private SubmissionRepository submissions;
    @Transactional
    public Submission create(SubmissionRequest request) {
    Submission submission = new Submission();
    ...
    return this.submissions.save(submission);
    }
    }
    

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27. Unit tests should not require any “framework”
    @Service
    public class SubmissionService {
    private final SubmissionRepository submissions;
    public SubmissionService(SubmissionRepository submissions) {
    this.submissions = submissions;
    }
    @Transactional
    public Submission create(SubmissionRequest request) {
    Submission submission = new Submission();
    ...
    return this.submissions.save(submission);
    }
    }
    

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28. Unit testing a client for an HTTP API
    class SpringBootMetadataReaderTests {
    private final RestTemplate restTemplate = new RestTemplate();
    private final MockRestServiceServer server = MockRestServiceServer.bindTo(
    this.restTemplate).build();
    @Test
    void readAvailableVersions() throws IOException {
    this.server.expect(requestTo("https://spring.io/project_metadata/spring-boot"))
    .andRespond(withSuccess(new ClassPathResource(
    "metadata/sagan/spring-boot.json"), MediaType.APPLICATION_JSON));
    ...
    this.server.verify();
    }
    }
    

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29. Integration Tests
    

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30. @SpringBootTest
    

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32. @JsonTest
    @WebMvcTest
    @WebFluxTest
    @DataJpaTest
    @JdbcTest
    @JooqTest
    @DataMongoTest
    @DataNeo4jTest
    @DataRedisTest
    @DataLdapTest
    @RestClientTest
    

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33. Slice test example
    @RestClientTest(SpringBootMetadataReader.class)
    class SpringBootMetadataReaderTests {
    @Autowired
    private SpringBootMetadataReader springBootMetadataReader;
    @Autowired
    private MockRestServiceServer server;
    @Test
    void readAvailableVersions() throws IOException {
    this.server.expect(requestTo("https://spring.io/project_metadata/spring-boot"))
    .andRespond(withSuccess(new ClassPathResource(
    "metadata/sagan/spring-boot.json"), MediaType.APPLICATION_JSON));
    ...
    this.server.verify();
    }
    }
    

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34. Slice test example with @MockBean
    @WebMvcTest(controllers = CfpController.class)
    class CfpControllerTest {
    @Autowired
    private MockMvc mvc;
    @MockBean
    private SubmissionService submissionService;
    @Test
    void submitTalk() throws Exception {
    given(this.submissionService.create(any())).willReturn(new Submission());
    this.mvc.perform(post("/submit")
    .param("title", "Alice in Wonderland")
    .param("summary", "my abstract"))
    .andExpect(status().isFound())
    .andExpect(header().string(HttpHeaders.LOCATION,
    "/submit?navSection=submit"));
    verify(this.submissionService).create(any());
    }
    }
    

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35. https://www.testcontainers.org
    

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36. testcontainers example
    @DisabledWithoutDockerTestcontainers
    public class ReactiveRestClientAutoConfigurationTests {
    @Container
    static ElasticsearchContainer elasticsearch = new ElasticsearchContainer();
    private ApplicationContextRunner contextRunner = new ApplicationContextRunner()
    .withConfiguration(AutoConfigurations.of(
    ReactiveRestClientAutoConfiguration.class));
    @Test
    void restClientCanQueryElasticsearchNode() {
    String endpoint = elasticsearch.getContainerIpAddress()
    + ":" + elasticsearch.getFirstMappedPort();
    this.contextRunner.withPropertyValues(
    "spring.data.elasticsearch.client.reactive.endpoints=" + endpoint)
    .run((context) -> {
    ReactiveElasticsearchClient client = context.getBean(
    ReactiveElasticsearchClient.class);
    ...
    });
    }
    }
    

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37. Testing Spring Boot
    

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38. ApplicationContextRunner
    ● Test utility to prepare a mini ApplicationContext suitable for a very precise
    scenario:
    ● Specific auto-configuration(s)
    ● User configuration, if any
    ● Environment tuning (properties customization)
    ● System properties handling
    ● Starts/Stop the context automatically with a ContextConsumer callback
    ● AssertJ style assert
    ● hasSingleBean, doesNotHaveBean, hasFailed
    ● getBean, getBeans, etc
    

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39. ApplicationContextRunner example
    @Test
    void shouldFailWhenNativeTypesAreNotAvailable() {
    this.contextRunner
    .run((context) -> {
    assertThat(context).hasFailed();
    assertThat(context.getStartupFailure())
    .hasRootCauseInstanceOf(
    NativeTypesNotAvailableException.class);
    });
    }
    

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40. ApplicationContextRunner example
    @Test
    void shouldFailWhenNativeTypesAreNotAvailable() {
    this.contextRunner
    .withConfiguration(AutoConfigurations.of(
    Neo4jDataAutoConfiguration.class,
    TransactionAutoConfiguration.class))
    .run((context) -> {
    assertThat(context).hasFailed();
    assertThat(context.getStartupFailure())
    .hasRootCauseInstanceOf(
    NativeTypesNotAvailableException.class);
    });
    }
    

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41. ApplicationContextRunner example
    @Test
    void shouldFailWhenNativeTypesAreNotAvailable() {
    this.contextRunner
    .withConfiguration(AutoConfigurations.of(
    Neo4jDataAutoConfiguration.class,
    TransactionAutoConfiguration.class))
    .withPropertyValues(
    "spring.data.neo4j.uri=bolt://localhost:7687",
    "spring.data.neo4j.use-native-types:true")
    .run((context) -> {
    assertThat(context).hasFailed();
    assertThat(context.getStartupFailure())
    .hasRootCauseInstanceOf(
    NativeTypesNotAvailableException.class);
    });
    }
    

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42. ApplicationContextRunner example
    @Test
    void shouldFailWhenNativeTypesAreNotAvailable() {
    this.contextRunner
    .withConfiguration(AutoConfigurations.of(
    Neo4jDataAutoConfiguration.class,
    TransactionAutoConfiguration.class))
    .withPropertyValues(
    "spring.data.neo4j.uri=bolt://localhost:7687",
    "spring.data.neo4j.use-native-types:true")
    .withClassLoader(new FilteredClassLoader(
    "org.neo4j.ogm.drivers.bolt.types"))
    .run((context) -> {
    assertThat(context).hasFailed();
    assertThat(context.getStartupFailure())
    .hasRootCauseInstanceOf(
    NativeTypesNotAvailableException.class);
    });
    }
    

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43. Classpath tuning
    @RunWith(ModifiedClassPathRunner.class)
    @ClassPathOverrides("javax.servlet:servlet-api:2.5")
    public class NoSuchMethodFailureAnalyzerTests {
    @Test
    public void noSuchMethodErrorIsAnalyzed() {
    Throwable failure = createFailure();
    assertThat(failure).isNotNull();
    FailureAnalysis analysis = new NoSuchMethodFailureAnalyzer()
    .analyze(failure);
    assertThat(analysis).isNotNull();
    ...
    }
    private Throwable createFailure() {
    ...
    }
    }
    

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44. Links
    ● https://spring.io/projects/spring-boot
    ● https://start.spring.io
    ● https://spring.io/guides
    ● https://concourse-ci.org/
    ● Testing Spring Boot Applications (Andy Wilkinson @ Spring I/O 2019): https://
    www.youtube.com/watch?v=5sjFn9BsAds
    

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45. © Copyright 2019 Pivotal Software, Inc. All rights Reserved.
    Thank you!
    @snicoll
    

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