Add DefaultBranchChangedEvent (#1763)

The DefaultBranchChangedEvent is fired whenever the default branch of repository changes.

scm-plugins/scm-git-plugin/src/test/java/sonia/scm/repository/DefaultBranchChangedDispatcherTest.java

@@ -0,0 +1,87 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2020-present Cloudogu GmbH and Contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package sonia.scm.repository;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.ArgumentCaptor;
+import org.mockito.Captor;
+import org.mockito.InjectMocks;
+import org.mockito.Mock;
+import org.mockito.junit.jupiter.MockitoExtension;
+import sonia.scm.api.v2.resources.GitRepositoryConfigChangedEvent;
+import sonia.scm.event.ScmEventBus;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.verifyNoInteractions;
+
+@ExtendWith(MockitoExtension.class)
+class DefaultBranchChangedDispatcherTest {
+
+  @Mock
+  private ScmEventBus eventBus;
+
+  @InjectMocks
+  private DefaultBranchChangedDispatcher dispatcher;
+
+  @Captor
+  private ArgumentCaptor<Object> eventCaptor;
+
+  private final Repository repository = RepositoryTestData.createHeartOfGold();
+
+  @Test
+  void shouldFireDefaultBranchChangedEvent() {
+    dispatcher.handleConfigUpdate(changedEvent("master", "main"));
+
+    verify(eventBus).post(eventCaptor.capture());
+    assertThat(eventCaptor.getValue())
+      .isInstanceOfSatisfying(DefaultBranchChangedEvent.class, event -> {
+        assertThat(event.getRepository()).isSameAs(repository);
+        assertThat(event.getOldDefaultBranch()).isEqualTo("master");
+        assertThat(event.getNewDefaultBranch()).isEqualTo("main");
+      });
+  }
+
+  @Test
+  void shouldNotFireEventIfDefaultBranchHasNotChanged() {
+    dispatcher.handleConfigUpdate(changedEvent("develop", "develop"));
+
+    verifyNoInteractions(eventBus);
+  }
+
+  private GitRepositoryConfigChangedEvent changedEvent(String oldDefaultBranch, String newDefaultBranch) {
+    return new GitRepositoryConfigChangedEvent(
+      repository, config(oldDefaultBranch), config(newDefaultBranch)
+    );
+  }
+
+  private GitRepositoryConfig config(String defaultBranch) {
+    GitRepositoryConfig config = new GitRepositoryConfig();
+    config.setDefaultBranch(defaultBranch);
+    return config;
+  }
+
+}