Mock Config Rule

MockConfigRule is JUnit @Rule that handles mocking of the Config class. This removes the need of PowerMocking Config, and considerably speeds up the test.

Note:
MockConfigRule supports JUnit 4 and JUnit 5 Legacy Engine. For JUnit Jupiter, use MockConfigExtension instead.

Creating the Rule

Like with any Rule, the only thing you need to do in order to incorporate it in your test class is to declare a public member annotated with @Rule or a public static member annotated with @ClassRule:

@Rule
public final MockConfigRule mcr = new MockConfigRule();

Mocking Different Config Values per Test

Now that you have the MockConfigRule defined, you can call the mockConfig method to mock a configuration value. E.g.:

public void testSomethingRegardingLDAP() {
   mcr.mockConfig(ConfigValues.LDAPSecurityAuthentication, ConfigCommon.defaultConfigurationVersion, "SIMPLE");
   // rest of the test the relies on the LDAPSecurityAuthentication configuraion.
}

Note:
If you omit the version parameter, ConfigCommon.defaultConfigurationVersion will be used by default:

public void testSomethingRegardingLDAP() {
   mcr.mockConfig(ConfigValues.LDAPSecurityAuthentication, "SIMPLE");
   // rest of the test the relies on the LDAPSecurityAuthentication configuraion.
}

Mocking The Same Config Values for the Entire Test Suite

The above approach is comfortable when each test requires a different configuration, but sometimes, you’d like you entire test-suite to use the same configurations. This can be done with a @Before annotation, but that would be tedious and repetitive. MockConfigRule provides an easier way to do this, in the @Rule’s construction time, using the mockConfig static creator, e.g.:

@ClassRule
public static final MockConfigRule mcr = new MockConfigRule(
    mockConfig(ConfigValues.LDAPSecurityAuthentication, "SIMPLE"),
    mockConfig(ConfigValues.SearchResultsLimit, 100),
    mockConfig(ConfigValues.AuthenticationMethod, "LDAP"),
    mockConfig(ConfigValues.DBEngine, "postgres")
);