add unit tests for anonymous realm

scm-webapp/src/test/java/sonia/scm/security/AnonymousRealmTest.java

@@ -0,0 +1,54 @@
+package sonia.scm.security;
+
+import org.apache.shiro.authc.AuthenticationInfo;
+import org.apache.shiro.authc.UsernamePasswordToken;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.InjectMocks;
+import org.mockito.Mock;
+import org.mockito.junit.jupiter.MockitoExtension;
+import sonia.scm.SCMContext;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.mockito.Mockito.when;
+
+@ExtendWith(MockitoExtension.class)
+class AnonymousRealmTest {
+
+  @Mock
+  private DAORealmHelperFactory realmHelperFactory;
+
+  @Mock
+  private DAORealmHelper realmHelper;
+
+  @Mock
+  private DAORealmHelper.AuthenticationInfoBuilder builder;
+
+  @InjectMocks
+  private AnonymousRealm realm;
+
+  @Mock
+  private AuthenticationInfo authenticationInfo;
+
+  @BeforeEach
+  void prepareObjectUnderTest() {
+    when(realmHelperFactory.create(AnonymousRealm.REALM)).thenReturn(realmHelper);
+    realm = new AnonymousRealm(realmHelperFactory);
+  }
+
+  @Test
+  void shouldDoGetAuthentication() {
+    when(realmHelper.authenticationInfoBuilder(SCMContext.USER_ANONYMOUS)).thenReturn(builder);
+    when(builder.build()).thenReturn(authenticationInfo);
+
+    AuthenticationInfo result = realm.doGetAuthenticationInfo(new AnonymousToken());
+    assertThat(result).isSameAs(authenticationInfo);
+  }
+
+  @Test
+  void shouldThrowIllegalArgumentExceptionForWrongTypeOfToken() {
+    assertThrows(IllegalArgumentException.class, () -> realm.doGetAuthenticationInfo(new UsernamePasswordToken()));
+  }
+}