#998 git: set repository head to default branch

scm-plugins/scm-git-plugin/src/main/java/sonia/scm/repository/GitHeadHandler.java

@@ -0,0 +1,53 @@
+package sonia.scm.repository;
+
+import com.google.common.base.Charsets;
+import com.google.common.base.Throwables;
+import com.google.common.io.Files;
+
+import javax.inject.Inject;
+import javax.inject.Singleton;
+import java.io.File;
+import java.io.IOException;
+
+@Singleton
+public class GitHeadHandler implements GitHeadResolver, GitHeadModifier {
+
+  private final GitRepositoryHandler repositoryHandler;
+
+  @Inject
+  public GitHeadHandler(GitRepositoryHandler repositoryHandler) {
+    this.repositoryHandler = repositoryHandler;
+  }
+
+  @Override
+  public String resolve(Repository repository) {
+    File headFile = findHeadFile(repository);
+    try {
+      String line = Files.readFirstLine(headFile, Charsets.UTF_8);
+      // TODO handle invalid head file
+      int index = line.indexOf(GitUtil.REF_HEAD_PREFIX);
+      return line.substring(index + GitUtil.REF_HEAD_PREFIX.length());
+    } catch (IOException e) {
+      // TODO
+      throw Throwables.propagate(e);
+    }
+  }
+
+  @Override
+  public void modify(Repository repository, String head) {
+    File headFile = findHeadFile(repository);
+    try {
+      String line = "ref: " + GitUtil.REF_HEAD_PREFIX + head + "\n";
+      Files.write(line, headFile, Charsets.UTF_8);
+    } catch (IOException e) {
+      // TODO
+      throw Throwables.propagate(e);
+    }
+  }
+
+  private File findHeadFile(Repository repository) {
+    // TODO handle non bare repositories
+    File directory = repositoryHandler.getDirectory(repository);
+    return new File(directory, "HEAD");
+  }
+}

scm-plugins/scm-git-plugin/src/main/java/sonia/scm/repository/GitHeadModifier.java

@@ -0,0 +1,7 @@
+package sonia.scm.repository;
+
+public interface GitHeadModifier {
+
+  void modify(Repository repository, String head);
+
+}

scm-plugins/scm-git-plugin/src/main/java/sonia/scm/repository/GitHeadResolver.java

@@ -0,0 +1,7 @@
+package sonia.scm.repository;
+
+public interface GitHeadResolver {
+
+  String resolve(Repository repository);
+
+}

scm-plugins/scm-git-plugin/src/main/java/sonia/scm/repository/GitRepositoryModifyListener.java

@@ -32,6 +32,7 @@ package sonia.scm.repository;
 
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.base.Objects;
+import com.google.common.base.Strings;
 import com.google.common.eventbus.Subscribe;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -40,6 +41,8 @@ import sonia.scm.HandlerEvent;
 import sonia.scm.event.ScmEventBus;
 import sonia.scm.plugin.ext.Extension;
 
+import javax.inject.Inject;
+
 /**
  * Repository listener which handles git related repository events.
  *
@@ -55,6 +58,15 @@ public class GitRepositoryModifyListener {
    */
   private static final Logger logger = LoggerFactory.getLogger(GitRepositoryModifyListener.class);
 
+  private final GitHeadResolver headResolver;
+  private final GitHeadModifier headModifier;
+
+  @Inject
+  public GitRepositoryModifyListener(GitHeadResolver headResolver, GitHeadModifier headModifier) {
+    this.headResolver = headResolver;
+    this.headModifier = headModifier;
+  }
+
   /**
    * Receives {@link RepositoryModificationEvent} and fires a {@link ClearRepositoryCacheEvent} if
    * the default branch of a git repository was modified.
@@ -65,13 +77,18 @@ public class GitRepositoryModifyListener {
   public void handleEvent(RepositoryModificationEvent event){
     Repository repository = event.getItem();
 
-    if ( isModifyEvent(event) && 
+    if ( isModifyEvent(event) && isGitRepository(event.getItem()) )
-         isGitRepository(event.getItem()) && 
-         hasDefaultBranchChanged(event.getItemBeforeModification(), repository)) 
     {
+      if (hasDefaultBranchChanged(event.getItemBeforeModification(), repository)) {
         logger.info("git default branch of repository {} has changed, sending clear cache event", repository.getId());
         sendClearRepositoryCacheEvent(repository);
       }
+
+      String defaultBranch = repository.getProperty(GitConstants.PROPERTY_DEFAULT_BRANCH);
+      if (defaultBranch != null && ! defaultBranch.equals(headResolver.resolve(repository))) {
+        headModifier.modify(repository, defaultBranch);
+      }
+    }
   }
 
   @VisibleForTesting

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

@@ -0,0 +1,60 @@
+package sonia.scm.repository;
+
+import com.google.common.base.Charsets;
+import com.google.common.io.Files;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.TemporaryFolder;
+import org.junit.runner.RunWith;
+import org.mockito.InjectMocks;
+import org.mockito.Mock;
+import org.mockito.runners.MockitoJUnitRunner;
+
+import java.io.File;
+import java.io.IOException;
+
+import static org.junit.Assert.*;
+import static org.mockito.Mockito.when;
+
+@RunWith(MockitoJUnitRunner.class)
+public class GitHeadHandlerTest {
+
+  @Rule
+  public TemporaryFolder temporaryFolder = new TemporaryFolder();
+
+  @Mock
+  private GitRepositoryHandler repositoryHandler;
+
+  @InjectMocks
+  private GitHeadHandler headHandler;
+
+  @Test
+  public void testResolve() throws IOException {
+    Repository repository = RepositoryTestData.createHeartOfGold("git");
+    create(repository, "master");
+
+    String head = headHandler.resolve(repository);
+    assertEquals("master", head);
+  }
+
+  @Test
+  public void testModify() throws IOException {
+    Repository repository = RepositoryTestData.createHeartOfGold("git");
+    File file = create(repository, "master");
+
+    headHandler.modify(repository, "develop");
+
+    assertEquals("ref: refs/heads/develop", Files.readFirstLine(file, Charsets.UTF_8));
+  }
+
+  private File create(Repository repository, String head) throws IOException {
+    File directory = temporaryFolder.newFolder();
+    File headFile = new File(directory, "HEAD");
+    Files.write(String.format("ref: refs/heads/%s\n", head), headFile, Charsets.UTF_8);
+
+    when(repositoryHandler.getDirectory(repository)).thenReturn(directory);
+
+    return headFile;
+  }
+
+}

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

@@ -33,7 +33,15 @@ package sonia.scm.repository;
 
 import org.junit.Test;
 import static org.junit.Assert.*;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
 import org.junit.Before;
+import org.junit.runner.RunWith;
+import org.mockito.InjectMocks;
+import org.mockito.Mock;
+import org.mockito.runners.MockitoJUnitRunner;
 import sonia.scm.HandlerEvent;
 
 /**
@@ -41,17 +49,17 @@ import sonia.scm.HandlerEvent;
  *
  * @author Sebastian Sdorra
  */
+@RunWith(MockitoJUnitRunner.class)
 public class GitRepositoryModifyListenerTest {
 
-  private GitRepositoryModifyTestListener repositoryModifyListener;
+  @Mock
+  private GitHeadResolver headResolver;
 
-  /**
+  @Mock
-   * Set up test object.
+  private GitHeadModifier headModifier;
-   */
+
-  @Before
+  @InjectMocks
-  public void setUpObjectUnderTest(){
+  private GitRepositoryModifyTestListener repositoryModifyListener;
-    repositoryModifyListener = new GitRepositoryModifyTestListener();
-  }
 
   /**
    * Tests happy path.
@@ -148,10 +156,42 @@ public class GitRepositoryModifyListenerTest {
     assertNull(repositoryModifyListener.repository);
   }
 
+  @Test
+  public void testModifyRepositoryHead() {
+    Repository old = RepositoryTestData.createHeartOfGold("git");
+    Repository current = RepositoryTestData.createHeartOfGold("git");
+    current.setProperty(GitConstants.PROPERTY_DEFAULT_BRANCH, "develop");
+
+    when(headResolver.resolve(current)).thenReturn("master");
+
+    RepositoryModificationEvent event = new RepositoryModificationEvent(current, old, HandlerEvent.MODIFY);
+    repositoryModifyListener.handleEvent(event);
+
+    verify(headModifier).modify(current, "develop");
+  }
+
+  @Test
+  public void testWithEqualHeads() {
+    Repository old = RepositoryTestData.createHeartOfGold("git");
+    Repository current = RepositoryTestData.createHeartOfGold("git");
+    current.setProperty(GitConstants.PROPERTY_DEFAULT_BRANCH, "develop");
+
+    when(headResolver.resolve(current)).thenReturn("develop");
+
+    RepositoryModificationEvent event = new RepositoryModificationEvent(current, old, HandlerEvent.MODIFY);
+    repositoryModifyListener.handleEvent(event);
+
+    verify(headModifier, never()).modify(current, "develop");
+  }
+
   private static class GitRepositoryModifyTestListener extends GitRepositoryModifyListener {
 
     private Repository repository;
 
+    public GitRepositoryModifyTestListener(GitHeadResolver headResolver, GitHeadModifier headModifier) {
+      super(headResolver, headModifier);
+    }
+
     @Override
     protected void sendClearRepositoryCacheEvent(Repository repository) {
       this.repository = repository;