Why do MockMvc tests suggest injecting WebApplicationContext @BeforeEach test?

Question

So the reference documentation suggests

    @BeforeEach
    void setup( WebApplicationContext wac) {
        this.mockMvc = MockMvcBuilders.webAppContextSetup( wac )
            .apply( SecurityMockMvcConfigurers.springSecurity() )
            .alwaysDo( print() )
            .build();
    }

why not do it as constructor injection instead? (I haven't tried this, I'm just assuming it doesn't immediately blow up)

    @Autowired
    MyControllerTest(
        @NonNull WebApplicatonContext wac
    ) {
        this.mockMvc = MockMvcBuilders.webAppContextSetup( wac )
            .apply( SecurityMockMvcConfigurers.springSecurity() )
            .alwaysDo( print() )
            .build();
    }

score 1 · Accepted Answer · answered Dec 28 '20 at 15:13

1

Whether you choose constructor injection, method injection, or field injection is a matter of taste when using JUnit Jupiter with the SpringExtension.

The example in the reference manual simply shows one way to do it using a @BeforeEach method since many people are familiar with performing test setup within a "before" method.

You can also set up your MockMvc instance within the test class constructor, and you can make your mockMvc field final if you like.

In this commit, I updated a test class in Spring's own test suite to demonstrate some of these techniques in practice.

Please note that the test class constructor does not need to be annotated with @Autowired if it accepts a single argument that is compatible with ApplicationContext.

answered Dec 28 '20 at 15:13

Sam Brannen

29,611
5
104
136

Thanks, I wasn't sure if maybe it was getting recreated each test, for a reason. – xenoterracide Dec 28 '20 at 15:28
So, did I answer your question then? – Sam Brannen Jan 02 '21 at 23:13
Yes, sorry, I forget about these sometimes – xenoterracide Jan 02 '21 at 23:52

Why do MockMvc tests suggest injecting WebApplicationContext @BeforeEach test?

1 Answers1