Test JUnit5

Since Camel 3.0

The camel-test-junit5 module is used for unit testing Camel.

The class org.apache.camel.test.junit5.CamelTestSupport provides a base JUnit class which you would extend and implement your Camel unit test.

Simple unit test example

As shown below is a basic junit test which uses camel-test-junit5. The createRouteBuilder method is used for build the routes to be tested. Then the methods with @Test annotations are JUnit test methods which will be executed. The base class CamelTestSupport has a number of helper methods to configure testing, see more at the javadoc of this class.

import org.apache.camel.RoutesBuilder;
import org.apache.camel.builder.RouteBuilder;
import org.apache.camel.test.junit5.CamelTestSupport;
import org.junit.jupiter.api.Test;

public class SimpleMockTest extends CamelTestSupport {

    @Test
    public void testMock() throws Exception {
        getMockEndpoint("mock:result").expectedBodiesReceived("Hello World");

        template.sendBody("direct:start", "Hello World");

        assertMockEndpointsSatisfied();
    }

    @Override
    protected RoutesBuilder createRouteBuilder() {
        return new RouteBuilder() {
            @Override
            public void configure() {
                from("direct:start").to("mock:result");
            }
        };
    }

}

Migrating Camel Tests from JUnit 4 to JUnit 5

Find below some hints to help in migrating camel tests from JUnit 4 to JUnit 5.

Projects using camel-test would need to use camel-test-junit5. For instance, maven users would update their pom.xml file as below:

<dependency>
  <groupId>org.apache.camel</groupId>
  <artifactId>camel-test-junit5</artifactId>
  <scope>test</scope>
</dependency>
It’s possible to run JUnit4 & JUnit5 based Camel tests side by side including the following dependencies camel-test, camel-test-junit5 and junit-vintage-engine. This configuration allows migrating Camel tests one by one.

Migration Steps

  • Imports of org.apache.camel.test.junit4.* should be replaced with org.apache.camel.test.junit5.*

  • TestSupport static methods should be imported where needed, for instance import static org.apache.camel.test.junit5.TestSupport.assertIsInstanceOf

  • Usage of the field CamelTestSupport.log should be replaced by another logger, for instance org.slf4j.LoggerFactory.getLogger(MyCamelTest.class);

  • Usage of the method CamelTestSupport.createRegistry should be replaced by CamelTestSupport.createCamelRegistry()

  • Overrides of isCreateCamelContextPerClass() returning false should be removed

  • Overrides of isCreateCamelContextPerClass() returning true should be replaced by @TestInstance(Lifecycle.PER_CLASS)

Once Camel related steps have been performed, there are still typical JUnit 5 migration steps to remember:

  • New JUnit 5 assertions should be imported where needed, for instance import static org.junit.jupiter.api.Assertions.assertEquals

  • Assertion messages should be moved to the last parameter where needed, for instance assertEquals("message", 2, 1) becomes assertEquals(2, 1, "message")

  • org.junit.Test should be changed in favor of org.junit.jupiter.api.Test

  • org.junit.Ignore should be changed in favor of org.junit.jupiter.api.Disabled

  • org.junit.Before should be changed in favor of org.junit.jupiter.api.BeforeEach

  • org.junit.After should be changed in favor of org.junit.jupiter.api.AfterEach

  • org.junit.BeforeClass should be changed in favor of import org.junit.jupiter.api.BeforeAll

  • org.junit.AfterClass should be changed in favor of import org.junit.jupiter.api.AfterAll

  • Built-in assertThat from third-party assertion libraries should be used. For instance, use org.hamcrest.MatcherAssert.assertThat from java-hamcrest

Depending on the context, more involved tips might be needed, please check the JUnit 5 User Guide.

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