Check for external merge tools during merge

Co-authored-by: Thomas Zerr<thomas.zerr@cloudogu.com>
Co-authored-by: René Pfeuffer<rene.pfeuffer@cloudogu.com>

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

@@ -0,0 +1,125 @@
+/*
+ * 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.spi;
+
+import org.eclipse.jgit.attributes.Attribute;
+import org.eclipse.jgit.attributes.Attributes;
+import org.eclipse.jgit.revwalk.RevCommit;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.junit.MockitoJUnitRunner;
+
+import java.io.IOException;
+import java.util.Collection;
+import java.util.Optional;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+@RunWith(MockitoJUnitRunner.class)
+public class AttributeAnalyzerTest extends AbstractGitCommandTestBase {
+
+  private AttributeAnalyzer attributeAnalyzer;
+
+  @Before
+  public void initAnalyzer() {
+    attributeAnalyzer = new AttributeAnalyzer(createContext(), new GitModificationsCommand(createContext()));
+  }
+
+  @Test
+  public void shouldNotGetAttributesIfFileDoesNotExist() throws IOException {
+    RevCommit commit = attributeAnalyzer.getTargetCommit("main");
+    Optional<Attributes> attributes = attributeAnalyzer.getAttributes(commit,"text1234.txt");
+
+    assertThat(attributes).isNotPresent();
+  }
+
+  @Test
+  public void shouldNotGetAttributesIfDoesNotExistForFilePattern() throws IOException {
+    RevCommit commit = attributeAnalyzer.getTargetCommit("main");
+    Optional<Attributes> attributes = attributeAnalyzer.getAttributes(commit,"text.txt");
+
+    assertThat(attributes).isNotPresent();
+  }
+
+  @Test
+  public void shouldGetAttributes() throws IOException {
+    RevCommit commit = attributeAnalyzer.getTargetCommit("main");
+    Optional<Attributes> attributes = attributeAnalyzer.getAttributes(commit,"text.ipr");
+
+    assertThat(attributes).isPresent();
+    Collection<Attribute> attributeCollection = attributes.get().getAll();
+    Attribute firstAttribute = attributeCollection.iterator().next();
+    assertThat(firstAttribute.getKey()).isEqualTo("merge");
+    assertThat(firstAttribute.getValue()).isEqualTo("mps");
+  }
+
+  @Test
+  public void shouldCheckIfMergeIsPreventedByExternalMergeTools_WithNoGitAttributes() {
+    String source = "change_possibly_needing_merge_tool";
+    String target = "removed_git_attributes";
+    assertThat(attributeAnalyzer.hasExternalMergeToolConflicts(source, target)).isFalse();
+  }
+
+  @Test
+  public void shouldCheckIfMergeIsPreventedByExternalMergeTools_WithEmptyGitAttributes() {
+    String source = "change_possibly_needing_merge_tool";
+    String target = "empty_git_attributes";
+    assertThat(attributeAnalyzer.hasExternalMergeToolConflicts(source, target)).isFalse();
+  }
+
+  @Test
+  public void shouldCheckIfMergeIsPreventedByExternalMergeTools_PatternFoundButNoMergeToolConfigured() {
+    String source = "change_possibly_needing_merge_tool";
+    String target = "removed_merge_tool_from_attributes";
+    assertThat(attributeAnalyzer.hasExternalMergeToolConflicts(source, target)).isFalse();
+  }
+
+  @Test
+  public void shouldCheckIfMergeIsPreventedByExternalMergeTools_WithoutMergeToolRelevantChange() {
+    String source = "change_not_needing_merge_tool";
+    String target = "conflicting_change_not_needing_merge_tool";
+    assertThat(attributeAnalyzer.hasExternalMergeToolConflicts(source, target)).isFalse();
+  }
+
+  @Test
+  public void shouldCheckIfMergeIsPreventedByExternalMergeTools_WithMergeToolRelevantChangeButFastForwardable() {
+    String source = "change_possibly_needing_merge_tool";
+    String target = "main";
+    assertThat(attributeAnalyzer.hasExternalMergeToolConflicts(source, target)).isFalse();
+  }
+
+  @Test
+  public void shouldCheckIfMergeIsPreventedByExternalMergeTools_WithMergeToolRelevantChangeAndPossibleConflict() {
+    String source = "change_possibly_needing_merge_tool";
+    String target = "conflicting_change_possibly_needing_merge_tool";
+    assertThat(attributeAnalyzer.hasExternalMergeToolConflicts(source, target)).isTrue();
+  }
+
+  @Override
+  protected String getZippedRepositoryResource() {
+    return "sonia/scm/repository/spi/scm-git-attributes-spi-test.zip";
+  }
+}

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

@@ -34,11 +34,14 @@ import sonia.scm.repository.work.WorkdirProvider;
 import java.io.IOException;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
 import static sonia.scm.repository.spi.MergeConflictResult.ConflictTypes.BOTH_MODIFIED;
 import static sonia.scm.repository.spi.MergeConflictResult.ConflictTypes.DELETED_BY_THEM;
 import static sonia.scm.repository.spi.MergeConflictResult.ConflictTypes.DELETED_BY_US;
 
-public class GitMergeCommand_Conflict_Test extends AbstractGitCommandTestBase {
+public class GitMergeCommandConflictTest extends AbstractGitCommandTestBase {
 
   static final String DIFF_HEADER = "diff --git a/Main.java b/Main.java";
   static final String DIFF_FILE_CONFLICT = "--- a/Main.java\n" +
@@ -93,7 +96,9 @@ public class GitMergeCommand_Conflict_Test extends AbstractGitCommandTestBase {
   }
 
   private MergeConflictResult computeMergeConflictResult(String branchToMerge, String targetBranch) {
-    GitMergeCommand gitMergeCommand = new GitMergeCommand(createContext(), new SimpleGitWorkingCopyFactory(new NoneCachingWorkingCopyPool(new WorkdirProvider(null, repositoryLocationResolver)), new SimpleMeterRegistry()));
+    AttributeAnalyzer attributeAnalyzer = mock(AttributeAnalyzer.class);
+    when(attributeAnalyzer.hasExternalMergeToolConflicts(any(), any())).thenReturn(false);
+    GitMergeCommand gitMergeCommand = new GitMergeCommand(createContext(), new SimpleGitWorkingCopyFactory(new NoneCachingWorkingCopyPool(new WorkdirProvider(null, repositoryLocationResolver)), new SimpleMeterRegistry()), attributeAnalyzer);
     MergeCommandRequest mergeCommandRequest = new MergeCommandRequest();
     mergeCommandRequest.setBranchToMerge(branchToMerge);
     mergeCommandRequest.setTargetBranch(targetBranch);

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

@@ -40,6 +40,9 @@ import org.junit.BeforeClass;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.jupiter.api.Assertions;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.junit.MockitoJUnitRunner;
 import sonia.scm.NoChangesMadeException;
 import sonia.scm.NotFoundException;
 import sonia.scm.repository.Added;
@@ -47,6 +50,9 @@ import sonia.scm.repository.GitTestHelper;
 import sonia.scm.repository.GitWorkingCopyFactory;
 import sonia.scm.repository.Person;
 import sonia.scm.repository.api.MergeCommandResult;
+import sonia.scm.repository.api.MergeDryRunCommandResult;
+import sonia.scm.repository.api.MergePreventReason;
+import sonia.scm.repository.api.MergePreventReasonType;
 import sonia.scm.repository.api.MergeStrategy;
 import sonia.scm.repository.work.NoneCachingWorkingCopyPool;
 import sonia.scm.repository.work.WorkdirProvider;
@@ -61,7 +67,9 @@ import java.util.function.Consumer;
 import java.util.function.Function;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.Mockito.when;
 
+@RunWith(MockitoJUnitRunner.class)
 @SubjectAware(configuration = "classpath:sonia/scm/configuration/shiro.ini", username = "admin", password = "secret")
 public class GitMergeCommandTest extends AbstractGitCommandTestBase {
 
@@ -71,6 +79,8 @@ public class GitMergeCommandTest extends AbstractGitCommandTestBase {
   public ShiroRule shiro = new ShiroRule();
   @Rule
   public BindTransportProtocolRule transportProtocolRule = new BindTransportProtocolRule();
+  @Mock
+  private AttributeAnalyzer attributeAnalyzer;
 
   @BeforeClass
   public static void setSigner() {
@@ -84,21 +94,60 @@ public class GitMergeCommandTest extends AbstractGitCommandTestBase {
     request.setBranchToMerge("mergeable");
     request.setTargetBranch("master");
 
-    boolean mergeable = command.dryRun(request).isMergeable();
+    MergeDryRunCommandResult result = command.dryRun(request);
 
-    assertThat(mergeable).isTrue();
+    assertThat(result.isMergeable()).isTrue();
+    assertThat(result.getReasons()).isEmpty();
   }
 
   @Test
-  public void shouldDetectNotMergeableBranches() {
+  public void shouldDetectNotMergeableBranches_FileConflict() {
     GitMergeCommand command = createCommand();
     MergeCommandRequest request = new MergeCommandRequest();
     request.setBranchToMerge("test-branch");
     request.setTargetBranch("master");
 
-    boolean mergeable = command.dryRun(request).isMergeable();
+    MergeDryRunCommandResult result = command.dryRun(request);
 
-    assertThat(mergeable).isFalse();
+    assertThat(result.isMergeable()).isFalse();
+    assertThat(result.getReasons().size()).isEqualTo(1);
+    assertThat(result.getReasons().stream().toList().get(0).getType()).isEqualTo(MergePreventReasonType.FILE_CONFLICTS);
+  }
+
+  @Test
+  public void shouldDetectNotMergeableBranches_ExternalMergeTool() {
+    String source = "mergeable";
+    String target = "master";
+    when(attributeAnalyzer.hasExternalMergeToolConflicts(source, target)).thenReturn(true);
+    GitMergeCommand command = createCommand();
+    MergeCommandRequest request = new MergeCommandRequest();
+    request.setBranchToMerge(source);
+    request.setTargetBranch(target);
+
+    MergeDryRunCommandResult result = command.dryRun(request);
+
+    assertThat(result.isMergeable()).isFalse();
+    assertThat(result.getReasons().size()).isEqualTo(1);
+    assertThat(result.getReasons().stream().toList().get(0).getType()).isEqualTo(MergePreventReasonType.EXTERNAL_MERGE_TOOL);
+  }
+
+  @Test
+  public void shouldDetectNotMergeableBranches_ExternalMergeToolAndFileConflict() {
+    String source = "test-branch";
+    String target = "master";
+    when(attributeAnalyzer.hasExternalMergeToolConflicts(source, target)).thenReturn(true);
+    GitMergeCommand command = createCommand();
+    MergeCommandRequest request = new MergeCommandRequest();
+    request.setBranchToMerge(source);
+    request.setTargetBranch(target);
+
+    MergeDryRunCommandResult result = command.dryRun(request);
+
+    assertThat(result.isMergeable()).isFalse();
+    assertThat(result.getReasons().size()).isEqualTo(2);
+    List<MergePreventReason> reasons = result.getReasons().stream().toList();
+    assertThat(reasons.get(0).getType()).isEqualTo(MergePreventReasonType.EXTERNAL_MERGE_TOOL);
+    assertThat(reasons.get(1).getType()).isEqualTo(MergePreventReasonType.FILE_CONFLICTS);
   }
 
   @Test
@@ -192,7 +241,7 @@ public class GitMergeCommandTest extends AbstractGitCommandTestBase {
   }
 
   @Test
-  public void shouldNotMergeConflictingBranches() {
+  public void shouldNotMergeConflictingBranches_FileConflict() {
     GitMergeCommand command = createCommand();
     MergeCommandRequest request = new MergeCommandRequest();
     request.setBranchToMerge("test-branch");
@@ -419,7 +468,7 @@ public class GitMergeCommandTest extends AbstractGitCommandTestBase {
   }
 
   @Test(expected = NotFoundException.class)
-  public void shouldHandleNotExistingTargetBranchInDryRun() {
+  public void shouldHandleNotExistingTargetBranchInDryRun() throws IOException {
     GitMergeCommand command = createCommand();
     MergeCommandRequest request = new MergeCommandRequest();
     request.setTargetBranch("not_existing");
@@ -517,7 +566,7 @@ public class GitMergeCommandTest extends AbstractGitCommandTestBase {
   }
 
   private GitMergeCommand createCommand(Consumer<Git> interceptor) {
-    return new GitMergeCommand(createContext(), new SimpleGitWorkingCopyFactory(new NoneCachingWorkingCopyPool(new WorkdirProvider(null, repositoryLocationResolver)), new SimpleMeterRegistry())) {
+    return new GitMergeCommand(createContext(), new SimpleGitWorkingCopyFactory(new NoneCachingWorkingCopyPool(new WorkdirProvider(null, repositoryLocationResolver)), new SimpleMeterRegistry()), attributeAnalyzer) {
       @Override
       <R, W extends GitCloneWorker<R>> R inClone(Function<Git, W> workerSupplier, GitWorkingCopyFactory workingCopyFactory, String initialBranch) {
         Function<Git, W> interceptedWorkerSupplier = git -> {

scm-plugins/scm-git-plugin/src/test/resources/sonia/scm/repository/mergetool.gitattributes

@@ -0,0 +1,20 @@
+*.ipr text merge=mps
+*.bat text
+*.txt text
+*.iml text
+*.xml text
+*.java text
+*.mpr text merge=mps
+*.css text
+*.html text
+*.dtd text
+*.sh text
+dependencies text merge=mps
+generated text merge=mps
+*.mps text merge=mps
+trace.info text merge=mps
+*.mpl text merge=mps
+*.msd text merge=mps
+*.devkit text merge=mps
+*.mpsr text merge=mps
+*.model text merge=mps