image:https://api.travis-ci.org/spring-projects/spring-test-data-geode.svg?branch=master["Build Status", link="https://travis-ci.org/spring-projects/spring-test-data-geode"] [[about]] == Spring Test Framework for Apache Geode & Pivotal GemFire The STDG project is a _Spring Data_ module, building on the core _Spring Framework's_ `TestContext`, used to write _Unit_ and _Integration Tests_ when building _Spring Data_ for https://geode.apache.org/[Apache Geode] & https://pivotal.io/pivotal-gemfire[Pivotal GemFire] (SDG) applications. This project was born from https://spring.io/projects/spring-data-gemfire[_Spring Data for Pivotal GemFire's_] (https://github.com/spring-projects/spring-data-gemfire[@GitHub]) https://github.com/spring-projects/spring-data-gemfire/tree/2.1.6.RELEASE/src/test/java/org/springframework/data/gemfire/test[test framework]. This _test framework_ is used in SDG's test suite to test the proper function of Apache Geode & Pivotal GemFire in a _Spring_ context. For several years now, users have asked for a way to test their Apache Geode & Pivotal GemFire based, _Spring_ applications reliably and easily, when writing _Unit_ and _Integrations_ tests. Additionally, STDG was created to consolidate the testing efforts, lessons learned, and knowledge of effectively testing all Spring for Apache Geode/Pivotal GemFire projects: _Spring Boot for Apache Geode & Pivotal GemFire_ (SBDG) and _Spring Session for Apache Geode & Pivotal GemFire_ (SSDG). Eventually, STDG will replace the SDG test classes so that tests and testing efforts are consistent across all Spring projects for Apache Geode/Pivotal GemFire: SDG, SBDG and SSDG. This (relatively) **new** project is still under development and will have documentation, examples and an extensive test suite once complete. In the meantime, you can review the https://github.com/spring-projects/spring-boot-data-geode/tree/master/spring-geode-autoconfigure/src/test/java/org/springframework/geode/boot/autoconfigure[test suite for SBDG] and the https://github.com/spring-projects/spring-session-data-geode/tree/master/spring-session-data-geode/src/test/java/org/springframework/session/data/gemfire[test suite for SSDG] to get a sense of how this project is used and works. [[code-of-conduct]] == Code of Conduct Please see our https://github.com/spring-projects/.github/blob/master/CODE_OF_CONDUCT.md[code of conduct] [[report-security-vulnerability]] == Reporting Security Vulnerabilities Please see our https://github.com/spring-projects/spring-test-data-geode/security/policy[Security policy]. [[license]] == License _Spring Test for Apache Geode_ and _Spring Test for Pivotal GemFire_ is Open Source Software released under the https://www.apache.org/licenses/LICENSE-2.0.html[Apache 2.0 license]. [[nutshell]] == STDG in a Nutshell Until proper documentation has been provided, this very short and simple tutorial will hopefully give you a better idea of how this project is used. [[unit-tests]] === Unit Testing with STDG We all write tests, right? TDD style? ;-) As we begin to write tests, we typically start with _Unit Tests_ since they are designed to test the subject in isolation, without dependencies, to get feedback quickly, i.e. "_Is my logic correct?_" It common when writing _Unit Tests_ to *mock* the dependencies since the test should assume that the dependencies "_work as designed_". During _Unit Testing_, it does not matter whether or not the dependencies actually work as expected (that is the purpose of _Integration Tests_), just that they have a contract and our application components, the "_Subject Under Test_" (SUT), honors that contract and uses the external dependencies correctly. Essentially we are asserting that the interactions between our application components and external dependencies is correct and the results lead to the desired outcome. Well, it is, or should be, no different when you are using Apache Geode or Pivotal GemFire. For instance, you might want to mock that your _Data Access Object_ (DAO) performs the proper interactions on a GemFire/Geode Region, performing the right CRUD operations, making sure the right (OQL) Queries are executed for the Use Case or business function and workflow being performed by the application. In this case, we don't care whether the Region is real or not, or that an OQL Query is actually well formed and would execute properly, performantly, returning the correct results. We would "mock" the Regions' behavior in this case to make sure that our DAO interactions with the Region are correct, that it handles the translation of Exceptions or other Error conditions, that it transforms values to/from the backend data store (i.e. Region), and so on. That is how you properly test the subject. To support _Unit Testing_ with Apache Geode or Pivotal GemFire in a Spring context, STDG provides the `@EnableGemFireMockObjects` annotation. If you want to use GemFire/Geode Mock Objects, e.g. a "mock" Region rather than a "live" Region, than you simply only need to annotate your test configuration with `@EnableGemFireMockObjects`. For example: .Unit Test with GemFire/Geode Mock Objects [source,java] ---- @RunWith(SpringRunner.class) @ContextConfiguration class ExampleUnitTestClass { // test case methods here @EnableGemFireMockObjects @ClientCacheApplication @EnableEntityDefinedRegions(clientRegionShortcut = ClientRegionShortcut.LOCAL) static class TestConfiguration { } } ---- In the example above, `@EnableGemFireMockObjects` creates "mocks" for the `ClientCache`, all the `Regions` identified and created by the `@EnableEntityDefinedRegions(..)` annotation, along with all the object GemFire/Geode object types. There are no "live" GemFire/Geode objects when "mocking" is enabled. Here is 1 https://github.com/spring-projects/spring-test-data-geode/blob/master/spring-data-geode-test/src/test/java/org/springframework/data/gemfire/MockClientCacheApplicationIntegrationTests.java[example] of a concrete _Unit Test_ in action, using STDG's `@EnableGemFireMockObjects` annotation. It really is that simple! TIP: Mocking GemFire/Geode objects outside a Spring context is possible, but beyond the scope of this guide for the time being. [[unit-tests-mock-region-data]] ==== Mock Regions with Data While implementing a fully capable GemFire/Geode Region would defeat the purpose of Mocking and Unit Testing in general, it is desirable to sometimes perform basic Region data access operations, such as `get` and `put`, with small quantities of data and emulate the same effects. As such, with STDG it is currently possible to perform the following Region data access operations: * `containsKey(key)` * `get(key)`, * `getEntry(key)`, * `invalidate(key)`, * `put(key, value)` * `size()`, The "mock" Region will function and behave similarly to an actual GemFire/Geode Region involving these data access operations. By way of example, this means you can do things like the following in a Unit Test with a "mock" Region: .Basic data access operations on a mocked Region [source,java] ---- @RunWith(SpringRunner.class) @ContextConfiguration class MyGeodeMockRegionUnitTests { @Resource(name = "Example") private Region mockRegion; @Test public void simpleGetAndPutRegionOpsWork() { mockRegion.put(1, "test"); assertThat(mockRegion).containsKey(1); assertThat(mockRegion.get(1)).isEqualTo("test"); } @ClientCacheApplication @EnableGemFireMockObjects static class TestConfiguration { @Bean("Example") ClienRegionFactoryBean mockRegion(GemFireCache gemfireCache) { ClientRegionFactoryBean mockRegion = new ClientRegionFactoryBean(); mockRegion.setCache(gemfireCache); return mockRegion; } } } ---- Of course, you can also perform similar Region data access operations using the _Spring Data Repository_ abstraction instead. The benefit of _Spring Data's_ _Repository_ abstraction is that it insulates your application from Apache Geode and hides the fact that you are interfacing with an Region under-the-hood by using the proper _Data Access Object_ (DAO) pattern. For example, you can "mock" a Region and `put`/`get` data using a _Spring Data Repository_ for the Region as demonstrated by the following code. Given a `Customer` application domain object annotated with the `@Region` mapping annotation: .Customer [source,java] ---- @Region("Customers") class Customer { @Id private Long id; ... } ---- Along with a SD _Repository_ for `Customers`: .CustomerRepository [source,java] ---- interface CustomerRepository extends CrudRepository { ... } ---- Then you can write a test class like the following, still using a "mock" Region to `put` and `get` actual data: .Spring Data Repository on a mocked Region [source,java] ---- @RunWith(SpringRunner.class) @ContextConfiguration class MySpringDataRepositoryWithMockRegionUnitTests { @Autowired private CustomerRepository customerRepository; @Test public void simpleRepositoryCrudOpsWork() { Customer jonDoe = ...; customerRepository.save(jonDoe); assertThat(customerRepository.existsById(jonDoe.getId()).isTrue(); assertThat(customerRepository.findById(jonDoe.getId()).orElse(null)).isEqualTo(jonDoe); } @ClientCacheApplication @EnableEntityDefinedRegions(basePackageClasses = Customer.class) @EnableGemfireRepositories(basePackageClasses = CustomerRepository.class) static class TestConfiguration { ... } } ---- Even though you are using _Spring Data Repositories_ and the `@EnableEntityDefinedRegions` annotation (perhaps; yes these components still work with Mocks and mock data), you can still autowire/inject the Region and access it directly in the same test class: .Accessing the mock Region directly in the SD Repository test [source,java] ---- @RunWith(SpringRunner.class) @ContextConfiguration class MySpringDataRepositoryWithMockRegionUnitTests { @Autowired private CustomerRepository customerRepository; @Resource Region customers; @Test public void simpleRepositoryCrudOpsWork() { ... } @Test public void customerRegionOpsWorkToo() { Customer janeDoe = ...; customers.put(janeDoe.getId(), janeDoe); assertThat(customers).containsKey(janeDoe.getId()); assertThat(customers.get(janeDoe.getId())).isEqualTo(janeDoe); assertThat(customerRepository.findById(janeDoe.getId()).orElse(null)).isEqualTo(janeDoe); } } ---- For clarification, obviously many of the Region functions and behaviors are not implemented, like persistence, or overflow to disk, distribution, replication, eviction, expiration, etc. If you find you need to test your application with these behaviors and functions, then it would clearly be better suited as an actual Integration Test at that point. [[unit-tests-mock-region-callbacks]] ==== Mock Region Callbacks A relatively *new* feature in STDG is the ability to register and invoke cache (Region) callbacks, such as `CacheListeners`, or a `CacheLoader` or a `CacheWriter`. Cache callbacks like `CacheListeners` or `CacheLoader/Writers` are user-defined, application objects that can be registered with a Region to listen for events, load data on cache misses, or write the Region's data to a backend, external data source. It is sometimes useful when testing to partially mock some dependencies (a.k.a. collaborators; e.g. Regions) while using live objects for others (e.g. cache callbacks like a `CacheListener`). The reason behind this testing strategy is that some objects are mostly infrastructure related (e.g. a Region), and not the primary focus of the test, while other objects are still very much tied to the application's function and behavior (e.g. a `CacheListener` or a `CacheLoader`), i.e. they are part of the application's workflow. As such, STDG not only allows you to register `CacheListeners` and `CacheLoaders/Writers` (you could do so before as well), but will now additionally invoke the Listeners, Loader and Writer at the appropriate point in the Region operation's process flow. For example, a registered `CacheWriter` is invoked before the object (value) is put into the Region using the `Region.put(key, value)` operation. This is exactly what GemFire/Geode does in order to ensure consistency with the backend, external data source. If the `CacheWriter` throws an exception during 1 of it's event handler callbacks (e.g. `beforeCreate(:EntryEvent)` then it will prevent the object from being inserted into the Region. The same behavior is true for a STDG mock Region. By way of example, let's demonstrate with a `CacheLoader`: .Application `CacheLoader` on mock Region [source,java] ---- @RunWith(SpringRunner.class) @ContextConfiguration class MyMockRegionWithCacheLoaderUnitTests { @Resource(name = "Example") private Region example; @Test public void cacheLoaderWorks() { assertThat(example.get("one")).isEqualTo(1); assertThat(example.get("two")).isEqualTo(2); ... } @ClientCacheApplication @EnableGemFireMockObjects static class TestConfiguration { @Bean ClienRegionFactoryBean exampleRegion(GemFireCache gemfireCache) { ClientRegionFactoryBean exampleRegion = new ClientRegionFactoryBean(); exampleRegion.setCache(gemfireCache); exampleRegion.setCacheLoader(counterCacheLoader()); return exampleRegion; } } @Bean CacheLoader counterCacheLoader() { AtomicInteger counter = new AtomicInteger(0); return new CacheLoader<>() { @Override public Object load(LoaderHelper helper) { return counter.incrementAndGet(); } }; } } ---- As seen in the test above, performing a `Region.get(key)` for keys "one" and "two" on an initially empty Region will result in cache misses, which will then invoke the registered, application "counter" `CacheLoader` to supply the value for the requested keys. You can register a `CacheWriter` along with 1 or more `CacheListeners` and they will be invoked, too. [[integration-testing]] === Integration Testing with STDG You should write many more _Unit Tests_ than _Integration Tests_ to get reliable and fast feedback. This is a no brainer and software development 101. However, _Unit Tests_ do not completely take the place of _Integration Tests_, either. Both are necessary, as are perhaps other forms of testing (e.g. Functional Testing, Acceptance Testing, Smoke Testing, Performance Testing, Concurrency Testing, etc). For instance, you should verify that the (OQL) Query you just constructed, maybe even generated, is well-formed and yields the desired results, is performant, and all that jazz. You can only reliably do that by executing the (OQL) Query against an actual GemFire/Geode Region with a properly constructed and deliberate data set. This sort _Integration Test_ does not have a complex arrangement, and can be performed simply by removing or disabling the `@EnableGemFireMockObjects` annotation in our previous example above. However, other forms of _Integration Testing_ might require a more complex arrangement, such as client/server integration tests. For instance, you may want to test that a client receives all the events from the server to which it has explicitly registered interests. For this type of test, you need to have a (1 or more) GemFire/Geode server(s) running, and perhaps even a few clients. Ideally, you want to fork a GemFire/Geode server JVM process in the _Integration Test_ class requiring a server instance. Once again, STDG comes to the rescue. For example: .Client/Server Integration Test [source,java] ---- @RunWith(SpringRunner.class) @ContextConfiguration(classes = GeodeClientTestConfiguration.class) class ExampleIntegrationTestClass extends ForkingClientServerIntegrationTestsSupport { @BeforeClass public static void startGemFireServer() { startGemFireSever(GeodeServerTestConfiguration.class); } // test case method here @CacheServerApplication @EnableEntityDefinedRegions static class GeodeServerTestConfiguration { public static void main(String[] args) { AnnotationConfigApplicationContext applicationContext = new AnnotationConfigApplicationContext(GeodeServerTestConfiguration.class); applicationContext.registerShutdownHook(); } } @ClientCacheApplication @EnableEntityDefinedRegions static class GeodeClientTestConfiguration { } } ---- First we extend the STDG provided `ForkingClientServerIntegrationTestsSupport` class. Then, we define a JUnit `@BeforeClass` static setup method to fork our GemFire/Geode JVM process using the `GeodeServerTestConfiguration.class` specifying exactly how the server should be configured and finally we create the matching `GeodeClientTestConfiguration` class to configure and bootstrap our JUnit, Spring `TestContext` based test, which acts as the client. STDG takes care of coordinating the client & server, using random connection ports, etc. You simply just need to provide the configuration of the client and server as required by your application and test case(s). Here is 1 https://github.com/spring-projects/spring-boot-data-geode/blob/master/spring-geode-autoconfigure/src/test/java/org/springframework/geode/boot/autoconfigure/security/ssl/AutoConfiguredSslIntegrationTests.java[example] of a concrete client/server _Integration Test_ extending STDG's `ForkingClientServerIntegrationTestsSupprt` class. Notice, too, that I am using SDG's https://docs.spring.io/spring-data/geode/docs/current/reference/html/#bootstrap-annotation-config[Annotation-based configuration model] (e.g. `CacheServerApplication`, `@EnableEntityDefinedRegions`) to make the GemFire/Geode configuration even easier. If you are using SBDG with this project, then some of the annotations are not even required (e.g. `ClientCacheApplication`). When SBDG & STDG are combined, the power you have is quite extensive. NOTE: Through the _Integration Test_ support provided by and in STDG is relatively simple, this is also not quite yet the ideal way for writing client/sever _Integration Tests_. Eventually, we want to include an annotation, something like `@ClientServerIntegrationTest(serverConfigClass = GeodeServerTestConfiguration.class)`, the equivalent to `@EnableGemFireMockObjects` for _Unit Testing_, to make configuration and testing of client/server applications that much easier. See https://github.com/spring-projects/spring-test-data-geode/issues/9[Issue #9] for more details. This feature would be loosely based on, and similar to, _Spring Boot_ https://docs.spring.io/spring-boot/docs/current/reference/html/boot-features-testing.html[Testing] with _Test Slices_. [[testing-logging-behavior]] === Asserting Logging Behavior It is sometimes necessary or useful to write tests to assert an application's logging behavior. For instance, if your application needs to log an event that occurred, output configuration meta-data on startup, alert a user to some system event such as low memory, out of disk space, or a temporary network outage, or whatever the case might be, it is useful to assert that your application logs an appropriate message. But, how do you assert that certain log events with an appropriate log message has been made by the application when the conditions constituting the log event have been arranged? Now, STDG provides the capability to 1) assert that your application, or an application component, made a log event at the appropriate moment and 2) that the log message communicates enough contextual-based information to be useful to the user of your application. To do this, STDG provides the `org.springframework.data.geode.tests.logging.slf4j.logback.TestAppender` class. This Log Appender can be used when your application logging framework is configured with _Logback_ as the provider. You declare the `TestAppender` in a `logback.xml` configuration file as follows: .logback.xml configuration file [source,xml] ---- TEST - %m%n ---- Then, the `TestAppender` can be used by registering it with a `Logger`: .Logger using the TestAppender [source,xml] ---- ---- For example, assume your application's `NetworkService` class uses the named `Logger` to log network events, e.g. a DDoS attack: .Application component with logging [source,java] ---- @Service class NetworkService { private final Logger logger = LoggerFactory.getLogger(NetworkService.class); void processDenialOfServiceAttack(NetworkEvent event) { logger.warn("A DDoS attack occured at {} from IP Address {}", event.getTime(), event.getIpAddress()); // process the network event logger.warn("Another log message"); } void processLoginRequest(LoginRequest request) { logger.info("User {} is attepting to login", request.getUser().getName()); // process login request } } ---- Then, it is a simple matter to test the logging behavior of your application by doing: .Test logging behavior of the NetworkService class [source,java] ---- class NetworkServiceUnitTests { private static TestAppender testAppender = TestAppender.getInstance(); private NetworkService service; @Before public void setup() { this.service = new NetworkService(); } @Test public void processDenialOfServiceAttackLogsNetworkEvent() { NetworkEvent event = ...; this.service.processDenialOfServiceAttack(event); assertThat(testAppender.lastLogMessage()) .isEqualTo("A DDoS attack occured at 2019-07-02 19:39:15 from IP Address 10.22.101.16"); assertThat(testAppender.lastLogMessage()) .isEqualTo("Another log message"); assertThat(testAppender.lastLogMessage()).isNull(); } @Test public void processLoginRequestDoesNotLogAnyMessageWithLogLevelSetToWarn() { LoginRequest request = ...; this.service.processLoginRequest(request); assertThat(testAppender.lastLogMessage()).isNull(); } } ---- You may also clear any remaining, pending log messages from the in-memory queue (`Stack`) by calling `TestAppender.clear()`. All log message recorded by the `TestAppender` are stored from the most recent log event to the earliest log event. Successively calling `TestAppender.lastLogMessage()` gets the most recent, last log message recorded first, then the next log message recorded before the last, most recent log message and so on until no more log messages for the operation under test exists, in which case `null` is returned from `lastLogMessage()` thereafter. [[conclusion]] === Conclusion Anyway, we hope this has intrigued your interests and gets you started for now. Ideas, contributions, or other feedback is most welcomed. Thank you!