Setup Options
MockMvc can be set up in one of two ways.
WebApplicationContext
-
Point to Spring configuration with Spring MVC and controller infrastructure in it.
- Standalone
-
Point directly to the controllers you want to test and programmatically configure Spring MVC infrastructure.
Which setup option should you use?
A WebApplicationContext
-based test loads your actual Spring MVC configuration,
resulting in a more complete integration test. Since the TestContext framework caches the
loaded Spring configuration, it helps keep tests running fast, even as you introduce more
tests in your test suite using the same configuration. Furthermore, you can override
services used by your controller using @MockitoBean
or @TestBean
to remain focused on
testing the web layer.
A standalone test, on the other hand, is a little closer to a unit test. It tests one controller at a time. You can manually inject the controller with mock dependencies, and it does not involve loading Spring configuration. Such tests are more focused on style and make it easier to see which controller is being tested, whether any specific Spring MVC configuration is required to work, and so on. The standalone setup is also a very convenient way to write ad-hoc tests to verify specific behavior or to debug an issue.
As with most "integration versus unit testing" debates, there is no right or wrong
answer. However, using standalone tests does imply the need for additional integration
tests to verify your Spring MVC configuration. Alternatively, you can write all your
tests with a WebApplicationContext
, so that they always test against your actual Spring
MVC configuration.