I'd like to test my Spring Boot command line application. I would like to mock certain beans (which I was able to do by annotating #ContextConfiguration(classes = TestConfig.class) at the top of my test class. In TestConfig.class, I override the beans that I would like to mock. I'd like Spring Boot to find the rest of the components. This seems to work.
The problem is that when I run the test, the entire application starts up as normal (ie. the run() method is called).
#Component
public class MyRunner implements CommandLineRunner {
//fields
#Autowired
public MyRunner(Bean1 bean1, Bean2 bean2) {
// constructor code
}
#Override
public void run(String... args) throws Exception {
// run method implementation
}
I've tried to override the MyRunner #Bean and put it in TestConfig.class, but that doesn't seem to work. I understand that I'm loading the regular application context, but that's what I'd like to do (I think?) since I would like to re-use all (or most) of the #Component I created in my Application, and only mock a tiny subset.
Any suggestions?
EDIT:
Application.java
#SpringBootApplication
public class Application {
public static void main(String[] args) {
SpringApplication.run(Application.class, args);
}
}
The answer was simpler than I thought. Add the MockBean in
#TestConfiguration
public class TestConfig {
#MockBean
private MyRunner myRunner;
}
We can use the #MockBean to add mock objects to the Spring application context. The mock will replace any existing bean of the same type in the application context.
So MyRunner.run() is never called but I can still use all the other beans in my application.
CommandLineRunners are ordinary beans with one exception:
After the application context is loaded, spring boot finds among all its beans the beans that implement this interface and calls their run method automatically.
Now, I would like you to ask to do the following:
Remove ContextConfiguration from the test and place a breakpoint in constructor of MyRunner. The test should look like this:
#RunWith(SpringRunner.class) // if you're on junit 4, adjust for junit 5 if you need
#SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.NONE)
public class MyTest {
#Autowired
private MyRunner myRunner;
#Test
public void testMe() {
System.out.println("hello");
}
}
Run the test and make sure that myRunner is loaded and its run method is called
Now mock this class with MockBean annotation:
#RunWith(SpringRunner.class) // if you're on junit 4, adjust for junit 5 if you need
#SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.NONE)
public class MyTest {
#MockBean
private MyRunner myRunner;
#Test
public void testMe() {
System.out.println("hello");
}
}
Run the test. Make sure that run method is not running. Your Application Context now should contain a mock implementation of your component.
If the above works, then the problem is with TestConfig and ContextConfiguration annotation. In general when you run without ContextConfiguration you give spring boot test engine a freedom to mimic the application context started as if its a real application (with autoconfigurations, property resolution, recursive bean scanning and so forth).
However if you put ContextConfiguration, spring boot test doesn't work like this - instead it only loads the beans that you've specified in that configuration. No Autoconfigurations, no recursive bean scanning happens for example.
Update
Based on OP's comment:
It looks like the MyRunner gets loaded when you put #ContextConfiguration because of component scanning. Since you have an annotation #Component placed on MyRunner class it can be discovered by Spring boot engine.
In fact there is a "dangerous" mix of two types of beans definitions here:
1. The beans defined with #Bean in #Configuration annotation
2. The beans found during component scanning.
Here is the question for you: If you don't want to mimic the application startup process and instead prefer to load only specific beans, why do you use #SpringBootTest at all? Maybe you can achieve the goal with:
#RunWith(SpringRunner.class)
#ContextConfiguration(YourConfig.class)
public class MyTest {
...
}
One way you could do this is to have 2 classes with the main method, one which sets up the "normal" context, and another that sets up the "mock" context:
Normal App Context, uses the usual Application
#SpringBootApplication(scanBasePackages = "com.example.demo.api")
public class Application {
public static void main(String[] args) {
SpringApplication.run(Application.class, args);
}
#Bean
public Foo foo() {
return new Foo("I am not mocked");
}
#Bean
public Bar bar() {
return new Bar("this is never mocked");
}
}
Add another Application class that overrides the normal context with the mocked one
#SpringBootApplication(scanBasePackageClasses = {MockApplication.class, Application.class})
#Component
public class MockApplication {
public static void main(String[] args) {
SpringApplication.run(MockApplication.class, args);
}
#Bean
public Foo foo() {
return new Foo("I am mocked");
}
}
When you run Application.main Foo will be "I am not mocked", when you run MockApplication.main() it will be "I am mocked"
I'm having a well working library and I would like to utilize the library in one of my sample Spring boot console application.
I built the library using the command mvn clean install and the newly generated .jar file I imported in my sample Spring boot console application.
I created a bean in my new sample application and tried to create an object of UserManagementService, which is in the external .jar and the said jar internally has two properties
External Jar's - Service file
public class UserManagementService {
#Autowired
UserService userService;
#Autowired
ManagementService managementService;
public String getUserFirstName(String userName) {
return userService.getUserFirstName(userName);
}
.. Rest of the implementation
}
These two autowired is not working and it has the value null moreover it throws an exception org.springframework.beans.factory.BeanDefinitionStoreException: Failed to parse configuration class...
My Sample Application:
public class ApplicationBean {
private UserManagementService userService = new UserManagementService();
public void run() {
if(userService == null) {
System.out.println("Oops");
}
String userFirstName = userService.getUserFirstName("Emma");
... Rest of the implementation
}
}
Kindly assist me how to fix this.
You need to declare your user management service as a bean in order to be able to inject it.
First Approach
Annotate the UserManagementService class with #Service if you have control over the library, UserService and ManagementService needs to be annotated with #Service too so they can be injected into UserManagementService. You may need to use #ComponentScan(basePackages = { "libray.package" }) in your spring app (over main class) to make it scan your library and load the services.
Second Approach
You make your library framework independent and make UserManagementService a simple POJO where you pass UserService and ManagementService as constructor arguments, then declare those beans in your spring app
public class ApplicationBean {
#Bean
public UserService userServiceProvider(){
return new UserService();
}
#Bean
public ManagementService managementServiceProvider(){
return new ManagementService();
}
#Bean
public UserManagementService userManagementServiceProvider(UserService userService, ManagementService managementService){
return new UserManagementService(userService, managementService);
}
}
These beans declaration go to application main class or to a class annotated with #Configuration
Base test class for integration testing imports base configuration with component scan that includes almost all packages. In one test class I want to override some beans with Mocs, but this inner configuration is scanned and overrides beans for all tests. Is there some way to avoid this?
I've found the way I like mocking beans with by essentially having a separate MockObjectsConfig class with the mock objects I want using the standard Spring Context Configuration, and then import it alongside my real test config. You can also annotate your mock bean with #Profile and test with #ActiveProfiles if you need to prevent a conflict there.
#Configuration
#Profile("!test")
public class MyRealConfigClass {
#Bean
public YetAnotherClass yetAnotherClass() {
return new YetAnotherClass();
}
}
#Configuration
#Profile("test")
public class MockObjectsConfig {
#Bean
public YetAnotherClass yetAnotherClass() {
Mockito.mock(YetAnotherClass.class); // and add any thenReturns, answers, etc. here
}
}
Then include it in your test like so:
#RunWith(SpringRunner.class)
#ContextConfiguration(classes = { MyRealConfigClass.class, MockObjectsConfig.class)
#ActiveProfiles({"test"})
public class MyJunitTest {
#Autowired
private RestController restController;
}
Then your mock bean will be used and not the real one from the production config.
I would like to be able to use a bean via auto-wiring and without having to directly use an ApplicationContext. Below is a dummy example of what I would like to be able to do.
Configuration Class
#Configuration
public class CoffeeConfig
{
#Bean
public CoffeeMachine provideCoffeeMachine()
{
return new CoffeeMachine(provideCoffeeBean());
}
#Bean
public CoffeeBean provideCoffeeBean()
{
return new CoffeeBean(Type.BEST);
}
}
Coffee Shop Class
#Component
public class CoffeeShop
{
#Autowired
private CoffeeMachine cMachine;
public void pourCoffee()
{
System.out.print("Pouring cup of coffee: " + cMachine.pour(Amount.8OZ));
}
}
In order to solve this, I have been reading through spring documentation and spring tutorials. The problem is, I haven't seen anyone attempt to illustrate how to do something as simple as this, and when they do, they end up resorting to using an application context. That being said, I know that if I am running unit tests with Spring, I can do the following:
Test Class
#RunWith(SpringJUnit4ClassRunner.class)
#ContextConfiguration(classes=CoffeeConfig.class, loader=AnnotationConfigContextLoader.class)
public class SpringIOCTests
{
#Autowired
public CoffeeMachine cMachine;
#Test
public void influxDevTest()
{
assertEquals(Type.BEST, cMachine.getBeans());
}
}
The way this configures leads me to believe that using auto-wiring in such a way should be attainable in the actual application instead of using these test-only dependencies such as the ContextConfiguration. I should also note that this unit test does pass.
Does Spring offer a methodology in which one can auto-wire dependencies in a nice and clean way avoiding the direct use of an application contexts?
For my Spring-Boot app I provide a RestTemplate though a #Configuration file so I can add sensible defaults(ex Timeouts). For my integration tests I would like to mock the RestTemplate as I dont want to connect to external services - I know what responses to expect. I tried providing a different implementation in the integration-test package in the hope that the latter will override the real implementation , but checking the logs it`s the other way around : the real implementation overrides the test one. How can I make sure the one from the TestConfig is the one used?
This is my config file :
#Configuration
public class RestTemplateProvider {
private static final int DEFAULT_SERVICE_TIMEOUT = 5_000;
#Bean
public RestTemplate restTemplate(){
return new RestTemplate(buildClientConfigurationFactory());
}
private ClientHttpRequestFactory buildClientConfigurationFactory() {
HttpComponentsClientHttpRequestFactory factory = new HttpComponentsClientHttpRequestFactory();
factory.setReadTimeout(DEFAULT_SERVICE_TIMEOUT);
factory.setConnectTimeout(DEFAULT_SERVICE_TIMEOUT);
return factory;
}
}
Integration test:
#RunWith(SpringJUnit4ClassRunner.class)
#SpringApplicationConfiguration(classes = TestConfiguration.class)
#WebAppConfiguration
#ActiveProfiles("it")
public abstract class IntegrationTest {}
TestConfiguration class:
#Configuration
#Import({Application.class, MockRestTemplateConfiguration.class})
public class TestConfiguration {}
And finally MockRestTemplateConfiguration
#Configuration
public class MockRestTemplateConfiguration {
#Bean
public RestTemplate restTemplate() {
return Mockito.mock(RestTemplate.class)
}
}
Since Spring Boot 1.4.x there is an option to use #MockBean annotation to fake Spring beans.
Reaction on comment:
To keep context in cache do not use #DirtiesContext, but use #ContextConfiguration(name = "contextWithFakeBean") and it will create separate context, while it will keep default context in cache. Spring will keep both (or how many contexts you have) in cache.
Our build is this way, where most of the tests are using default non-poluted config, but we have 4-5 tests that are faking beans. Default context is nicely reused
1.
You can use #Primary annotation:
#Configuration
public class MockRestTemplateConfiguration {
#Bean
#Primary
public RestTemplate restTemplate() {
return Mockito.mock(RestTemplate.class)
}
}
BTW, I wrote blog post about faking Spring bean
2.
But I would suggest to take a look at Spring RestTemplate testing support. This would be simple example:
private MockRestServiceServer mockServer;
#Autowired
private RestTemplate restTemplate;
#Autowired
private UsersClient usersClient;
#BeforeMethod
public void init() {
mockServer = MockRestServiceServer.createServer(restTemplate);
}
#Test
public void testSingleGet() throws Exception {
// GIVEN
int testingIdentifier = 0;
mockServer.expect(requestTo(USERS_URL + "/" + testingIdentifier))
.andExpect(method(HttpMethod.GET))
.andRespond(withSuccess(TEST_RECORD0, MediaType.APPLICATION_JSON));
// WHEN
User user = usersClient.getUser(testingIdentifier);
// THEN
mockServer.verify();
assertEquals(user.getName(), USER0_NAME);
assertEquals(user.getEmail(), USER0_EMAIL);
}
More examples can be found in my Github repo here
The Problem in your configuration is that you are using #Configuration for your test configuration. This will replace your main configuration. Instead use #TestConfiguration which will append (override) your main configuration.
46.3.2 Detecting Test Configuration
If you want to customize the primary configuration, you can use a
nested #TestConfiguration class. Unlike a nested #Configuration class,
which would be used instead of your application’s primary
configuration, a nested #TestConfiguration class is used in addition
to your application’s primary configuration.
Example using SpringBoot:
Main class
#SpringBootApplication() // Will scan for #Components and #Configs in package tree
public class Main{
}
Main config
#Configuration
public void AppConfig() {
// Define any beans
}
Test config
#TestConfiguration
public void AppTestConfig(){
// override beans for testing
}
Test class
#RunWith(SpringRunner.class)
#Import(AppTestConfig.class)
#SpringBootTest
public void AppTest() {
// use #MockBean if you like
}
Note: Be aware, that all Beans will be created, even those that you override. Use #Profile if you wish not to instantiate a #Configuration.
#MockBean and bean overriding used by the OP are two complementary approaches.
You want to use #MockBean to create a mock and forget the real implementation : generally you do that for slice testing or integration testing that doesn't load some beans which class(es) you are testing depend on and that you don't want to test these beans in integration.
Spring makes them by default null, you will mock the minimal behavior for them to fulfill your test.
#WebMvcTest requires very often that strategy as you don't want to test the whole layers and #SpringBootTest may also require that if you specify only a subset of your beans configuration in the test configuration.
On the other hand, sometimes you want to perform an integration test with as many real components as possible, so you don't want to use #MockBean but you want to override slightly a behavior, a dependency or define a new scope for a bean, in this case, the approach to follow is bean overriding :
#SpringBootTest({"spring.main.allow-bean-definition-overriding=true"})
#Import(FooTest.OverrideBean.class)
public class FooTest{
#Test
public void getFoo() throws Exception {
// ...
}
#TestConfiguration
public static class OverrideBean {
// change the bean scope to SINGLETON
#Bean
#Scope(ConfigurableBeanFactory.SINGLETON)
public Bar bar() {
return new Bar();
}
// use a stub for a bean
#Bean
public FooBar BarFoo() {
return new BarFooStub();
}
// use a stub for the dependency of a bean
#Bean
public FooBar fooBar() {
return new FooBar(new StubDependency());
}
}
}
With #Primary annotation, Bean overriding works with Spring Boot 1.5.X but fails with Spring Boot 2.1.X it throw error:
Invalid bean definition with name 'testBean' defined in sample..ConfigTest$SpringConfig:..
There is already .. defined in class path resource [TestConfig.class]] bound
Please add below properties= which will instruct Spring explicitly to allow overriding, it is self explainatory.
#SpringBootTest(properties = ["spring.main.allow-bean-definition-overriding=true"])
UPDATE: You can add the same property in application-test.yml (file name depend upon what test profile name you are tests with)
Getting a little deeper into it, see my second answer.
I solved the Problem using
#SpringBootTest(classes = {AppConfiguration.class, AppTestConfiguration.class})
instead of
#Import({ AppConfiguration.class, AppTestConfiguration.class });
In my case the Test is not in the same package as the App. So I need to specify the AppConfiguration.class (or the App.class) explicit. If you use the same package in the test, than I guess you could just write
#SpringBootTest(classes = AppTestConfiguration.class)
instead of (not working)
#Import(AppTestConfiguration.class );
It is pretty wired to see that this is so different. Maybe some one can explain this. I could not find any good answers until now. You might think, #Import(...) is not picked up if #SpringBootTestsis present, but in the log the overriding bean shows up. But just the wrong way around.
By the way, using #TestConfiguration instead #Configuration also makes no difference.
I´ve declared an inner configuration class within my test because I wanted to overwrite just a single method
#SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)
public class FileNotificationWebhookTest{
public static class FileNotificationWebhookTestConfiguration {
#Bean
#Primary
public FileJobRequestConverter fileJobRequestConverter() {
return new FileJobRequestConverter() {
#Override
protected File resolveWindowsPath(String path) {
return new File(path);
}
};
}
}
}
However,
Declaring the configuration in #SpringBootTest did not work:
#SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT,classes = {FileNotificationWebhookTest.FileNotificationWebhookTestConfiguration.class})
or annotating the test configuration with #Configuration did not work:
#Configuration
public static class FileNotificationWebhookTestConfiguration {
}
and was leading to
Caused by: org.springframework.context.ApplicationContextException:
Unable to start web server; nested exception is
org.springframework.context.ApplicationContextException: Unable to
start ServletWebServerApplicationContext due to missing
ServletWebServerFactory bean.
What did work for me ( contrary to some other posts here) was using #Import
#SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)
#Import(FileNotificationWebhookTest.FileNotificationWebhookTestConfiguration.class)
class FileNotificationWebhookTest {
}
Using Spring: 5.3.3 with Spring-Boot-Starter: 2.4.2
#MockBean creates Mockito mock instead of production build.
If you do not want to use Mockito, but provide a replacement in some other way (i.e. by disabling some features of bean with feature toggles), I suggest using combination of #TestConfiguration (since Spring Boot 1.4.0) and #Primary annotation.
#TestConfiguration will load your default context and apply your #TestConfiguration piece in addition to it. Adding #Primary will force your mocked RestTemplate to be injected to it's dependents.
See simplified example below:
#SpringBootTest
public class ServiceTest {
#TestConfiguration
static class AdditionalCfg {
#Primary
#Bean
RestTemplate rt() {
return new RestTemplate() {
#Override
public String exec() {
return "Test rest template";
}
};
}
}
#Autowired
MyService myService;
#Test
void contextLoads() {
assertThat(myService.invoke()).isEqualTo("Test rest template");
}
}
This is super weird.
In my case, (Spring Boot 2.6.7), I could simply #Import MyTestConfiguration containing a custom #Primary #Bean into my #SpringBootTest, and everything worked.
Right until I needed to explicitly name my bean.
Then I suddenly had to resort to
#SpringBootTest(
properties = ["spring.main.allow-bean-definition-overriding=true"],
classes = [MyTestConfig::class],
)
Check this answer along with others provided in that thread.
It's about overriding bean in Spring Boot 2.X, where this option was disabled by default. It also has some ideas about how to use Bean Definition DSL if you decided to take that path.
The simplest solution I found was to set this property in application.properties:
spring.main.allow-bean-definition-overriding=true
This will enable overriding of beans.
Next, create a configuration class in test, and annotate your bean with:
#Bean
#Primary
This way, this bean will override your usual bean when running tests.