Testing Code

Terminology 
 
 Test Fixture - A fixed state of a set of objects used as a baseline for running tests. There should be a well known and fixed environment in which tests are run so that the results are repeatable. 
 Unit Tests / Unit Testing - Code written to test code uder test
 
 Designed to test specific sections of code 
 Ideally code coverage is maybe 70-80% 
 Should be small and fast 
 No external dependencies
 
 No databases or spring components 
 
 
 
 
 Integration Tests - Designed to test behaviors between objecrts and parts of the overall system
 
 Much larger scope 
 Can include the Spring Context, databases, and message brokers 
 Much slower than unit tests 
 
 
 Functional Tests - Testing a running application
 
 Likely deployed in a test env 
 Functional touch points are tested 
 
 
 Test Driven Development - Write Tests first, which of course fail, then code to 'fix' it 
 BDD - Specifies that tests of any unit of software should be specified in terms of desired behavior of the unit
 
 Often implemented with DSLs to create natural language tests 
 JBehave, Cucumber, Spock 
 
 
 Mock - A fake implementation of a class used for testing. Like a test Double. 
 Spy - A partial mock, allowing you to override select methods of a real class.
 
 Generally Mocking is more popular than Spying 
 
 
 
 Testing Goals 
 
 Generally you want the majority of tests to be unit tests. 
 Bringing up the Spring Context makes your test exponentially slower 
 Try to test specific business logic in unit tests 
 Use integration tests to test interactions 
 Think of a pyramid. Base is unit tests, middle is integration, top is functional tests 
 
 Test Scope Dependencies 
 
 Using spring-boot-starter-test will load the following:
 
 JUnit - the de-facto standard for unit testing 
 Spring Test and Spring Boot Test - Utilites and integration test support for Spring Boot applications 
 AssertJ - fluent assertion library 
 Hamcrest - A library of matcher objects 
 Mockito - A Java mocking framework 
 JSONassert - An assertion library for JSON 
 JSONPath - XPath for JSON 
 
 
 
 JUnit Annotations 
 
 Spring Boot Annotations