To enable Testing add the following dependency to your project’s pom.xml (see Managing Dependencies).

<dependency>
    <groupId>io.helidon.microprofile.tests</groupId>
    <artifactId>helidon-microprofile-tests-junit5</artifactId>
    <scope>test</scope>
</dependency>

A test can be annotated with io.helidon.microprofile.tests.junit5.HelidonTest annotation to mark it as a CDI test. This annotation will start the CDI container before any test method is invoked, and stop it after the last method is invoked. This annotation also enables injection into the test class itself.

The annotations described in this section are inherited (for the non-repeatable ones), and additive (for repeatable). So if you declare @DisableDiscovery on abstract class, all implementations will have discovery disabled, unless you annotate the implementation class with @DisableDiscovery(false). If you declare @AddBean on both abstract class and implementation class, both beans will be added.

In addition to this simplification, the following annotations are supported:

• io.helidon.microprofile.tests.junit5.AddBean - to add one or more beans to the container (if not part of a bean archive, or when discovery is disabled)

• io.helidon.microprofile.tests.junit5.AddExtension - to add one or more CDI extensions to the container (if not added through service loader, or when discovery is disabled)

• io.helidon.microprofile.tests.junit5.AddConfig - to add one or more configuration properties to MicroProfile config without the need of creating a microprofile-config.properties file

• io.helidon.microprofile.tests.junit5.DisableDiscovery - to disable automated discovery of beans and extensions

@HelidonTest
@DisableDiscovery
@AddBean(MyBean.class)
@AddExtension(ConfigCdiExtension.class)
@AddConfig(key = "app.greeting", value = "TestHello")
class TestNoDiscovery {
    @Inject
    private MyBean myBean;

    @Test
    void testGreeting() {
        assertThat(myBean, notNullValue());
        assertThat(myBean.greeting(), is("TestHello"));
    }
}

A test can be annotated as follows:

@HelidonTest(resetPerTest = true)

This will change the behavior as follows:

• A new CDI container is created for each test method invocation

• annotations to add config, beans and extension can be added for each method in addition to the class

• you cannot inject fields or constructor parameters of the test class itself (as a single instance is shared by more containers)

• you can add SeContainer as a method parameter of any test method and you will get the current container

In addition to the @AddConfig annotation, you can also use @Configuration to configure additional classpath properties config sources using configSources, and to mark that a custom configuration is desired. If @Configuration(useExisting=true), the existing (or default) MicroProfile configuration would be used. In this case it is important to set property mp.initializer.allow=true in order CDI container to start, when used with @HelidonTest. You can set up config in @BeforeAll method and register it with ConfigProviderResolver using MP Config APIs, and declare @Configuration(useExisting=true). Note that this is not compatible with repeatable tests that use method sources that access CDI, as we must delay the CDI startup to the test class instantiation (which is too late, as the method sources are already invoked by this time).

If you want to use method sources that use CDI with repeatable tests, please do not use @Configuration(useExisting=true)

The following types are available for injection (when a single CDI container is used per test class):

• WebTarget - a JAX-RS client’s target configured for the current hostname and port when helidon-micorprofile-server is on the classpath

The following types are available as method parameters (in any type of Helidon tests):

• WebTarget - a JAX-RS client’s target configured for the current hostname and port when helidon-micorprofile-server is on the classpath

• SeContainer - the current container instance