As you typically would, with any software project, running the unit tests locally is no different for Serverless applications. Developers run them before pushing changes to a code repository. So, go ahead and run the unit tests for your project.
In the terminal, run this command from the sam-app/HelloWorldFunction folder to run the unit tests:
cd ~/environment/sam-app/HelloWorldFunction
mvn test
The tests should fail. This is expected!
Makes sense right? We changed the response message to hello my friend and the unit test was expecting hello world. This is an easy fix, let’s update the unit test.
Open the file sam-app/HelloWorldFunction/src/test/java/helloworld and update the expected value for the response
to match the new message. The unit test should look like this after the update:
package helloworld;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertNotNull;
import static org.junit.Assert.assertTrue;
import org.junit.Test;
public class AppTest {
@Test
public void successfulResponse() {
App app = new App();
GatewayResponse result = (GatewayResponse) app.handleRequest(null, null);
assertEquals(result.getStatusCode(), 200);
assertEquals(result.getHeaders().get("Content-Type"), "application/json");
String content = result.getBody();
assertNotNull(content);
assertTrue(content.contains("\"message\""));
assertTrue(content.contains("\"hello my friend\""));
}
}
Run the same command again.
mvn test
Now the tests should pass:
This project uses the jUnit Framework for running the unit tests, but you can chose any other framework. SAM doesn’t enforce any particular one. You can continue to have the same unit testing workflow that you do in a non-serverless application.