Introduce test for merges with multiple ancestors

Bug: 535200
Change-Id: I38f54baa9ce655fee60b1ed86ee850693e9555f1

9 files changed, 142 insertions, 1 deletions

diff --git a/plugins/org.eclipse.emf.compare.ide.ui.tests.git.framework/src/org/eclipse/emf/compare/ide/ui/tests/git/framework/annotations/GitMerge.java b/plugins/org.eclipse.emf.compare.ide.ui.tests.git.framework/src/org/eclipse/emf/compare/ide/ui/tests/git/framework/annotations/GitMerge.java
index a9670377c..803b6f44c 100644
--- a/plugins/org.eclipse.emf.compare.ide.ui.tests.git.framework/src/org/eclipse/emf/compare/ide/ui/tests/git/framework/annotations/GitMerge.java
+++ b/plugins/org.eclipse.emf.compare.ide.ui.tests.git.framework/src/org/eclipse/emf/compare/ide/ui/tests/git/framework/annotations/GitMerge.java
@@ -21,6 +21,7 @@ import org.eclipse.emf.compare.ide.ui.tests.git.framework.GitTestSupport;
 import org.eclipse.jgit.api.MergeResult;
 import org.eclipse.jgit.api.Status;
 import org.eclipse.jgit.lib.Repository;
+import org.junit.Test.None;
 
 /**
  * Annotation used to test the merge of models.
@@ -80,4 +81,12 @@ public @interface GitMerge {
 	 */
 	String remote();
 
+	/**
+	 * Optionally specify an exception that is expected to be thrown by the test. The test will fail if this
+	 * exception is not thrown.
+	 * 
+	 * @return The expected exception thrown by this test.
+	 */
+	Class<? extends Throwable> expected() default None.class;
+
 }
diff --git a/plugins/org.eclipse.emf.compare.ide.ui.tests.git.framework/src/org/eclipse/emf/compare/ide/ui/tests/git/framework/internal/statements/AbstractGitOperationStatement.java b/plugins/org.eclipse.emf.compare.ide.ui.tests.git.framework/src/org/eclipse/emf/compare/ide/ui/tests/git/framework/internal/statements/AbstractGitOperationStatement.java
index c22f82de4..1f54db079 100644
--- a/plugins/org.eclipse.emf.compare.ide.ui.tests.git.framework/src/org/eclipse/emf/compare/ide/ui/tests/git/framework/internal/statements/AbstractGitOperationStatement.java
+++ b/plugins/org.eclipse.emf.compare.ide.ui.tests.git.framework/src/org/eclipse/emf/compare/ide/ui/tests/git/framework/internal/statements/AbstractGitOperationStatement.java
@@ -11,6 +11,8 @@
  *******************************************************************************/
 package org.eclipse.emf.compare.ide.ui.tests.git.framework.internal.statements;
 
+import static org.junit.Assert.fail;
+
 import org.eclipse.core.runtime.preferences.IEclipsePreferences;
 import org.eclipse.core.runtime.preferences.InstanceScope;
 import org.eclipse.egit.core.Activator;
@@ -19,6 +21,7 @@ import org.eclipse.emf.compare.ide.ui.tests.framework.EMFCompareTestConfiguratio
 import org.eclipse.emf.compare.ide.ui.tests.framework.ResolutionStrategyID;
 import org.eclipse.emf.compare.ide.ui.tests.git.framework.GitMergeStrategyID;
 import org.eclipse.emf.compare.ide.ui.tests.git.framework.GitTestSupport;
+import org.junit.Test.None;
 import org.junit.runners.model.FrameworkMethod;
 
 /**
@@ -71,6 +74,7 @@ public abstract class AbstractGitOperationStatement extends AbstractGitStatement
 		setEMFComparePreferences();
 		String from = InternalGitTestSupport.normalizeBranch(getCheckoutedBranch());
 		String to = InternalGitTestSupport.normalizeBranch(getOtherBranch());
+		Class<? extends Throwable> expected = getExpectedException();
 
 		GitTestSupport gitTestsSupport = new GitTestSupport();
 		try {
@@ -79,6 +83,15 @@ public abstract class AbstractGitOperationStatement extends AbstractGitStatement
 			callGitOperation(gitTestsSupport, from, to);
 			Object[] parameters = createParameters(test.getMethod(), gitTestsSupport);
 			test.invokeExplosively(testObject, parameters);
+			if (expected != None.class) {
+				fail("Expected exception : " + expected.getName()); //$NON-NLS-1$
+			}
+		} catch (Throwable e) {
+			if (expected.isAssignableFrom(e.getClass())) {
+				// success
+			} else {
+				throw e;
+			}
 		} finally {
 			restoreEMFComparePreferences();
 			gitTestsSupport.tearDown();
@@ -102,6 +115,15 @@ public abstract class AbstractGitOperationStatement extends AbstractGitStatement
 	protected abstract String getOtherBranch();
 
 	/**
+	 * Returns the exception that is expected to be thrown by this test.
+	 * 
+	 * @return The exception that is expected to be thrown by this test.
+	 */
+	protected Class<? extends Throwable> getExpectedException() {
+		return None.class;
+	}
+
+	/**
 	 * Call the Git operation used in for the test. This method have to be sub-classed by clients to call the
 	 * correct operation.
 	 * 
diff --git a/plugins/org.eclipse.emf.compare.ide.ui.tests.git.framework/src/org/eclipse/emf/compare/ide/ui/tests/git/framework/internal/statements/GitMergeStatement.java b/plugins/org.eclipse.emf.compare.ide.ui.tests.git.framework/src/org/eclipse/emf/compare/ide/ui/tests/git/framework/internal/statements/GitMergeStatement.java
index 657d411ce..3068d5c85 100644
--- a/plugins/org.eclipse.emf.compare.ide.ui.tests.git.framework/src/org/eclipse/emf/compare/ide/ui/tests/git/framework/internal/statements/GitMergeStatement.java
+++ b/plugins/org.eclipse.emf.compare.ide.ui.tests.git.framework/src/org/eclipse/emf/compare/ide/ui/tests/git/framework/internal/statements/GitMergeStatement.java
@@ -63,4 +63,10 @@ public class GitMergeStatement extends AbstractGitOperationStatement {
 		return merge.remote();
 	}
 
+	@Override
+	protected Class<? extends Throwable> getExpectedException() {
+		GitMerge merge = test.getAnnotation(GitMerge.class);
+		return merge.expected();
+	}
+
 }
diff --git a/plugins/org.eclipse.emf.compare.ide.ui.tests.git/src/org/eclipse/emf/compare/ide/ui/tests/merge/MultipleAncestorsTest.java b/plugins/org.eclipse.emf.compare.ide.ui.tests.git/src/org/eclipse/emf/compare/ide/ui/tests/merge/MultipleAncestorsTest.java
new file mode 100644
index 000000000..8d5d56e50
--- /dev/null
+++ b/plugins/org.eclipse.emf.compare.ide.ui.tests.git/src/org/eclipse/emf/compare/ide/ui/tests/merge/MultipleAncestorsTest.java
@@ -0,0 +1,103 @@
+package org.eclipse.emf.compare.ide.ui.tests.merge;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+
+import java.util.List;
+
+import org.eclipse.core.resources.IProject;
+import org.eclipse.emf.compare.ide.ui.tests.git.framework.GitTestRunner;
+import org.eclipse.emf.compare.ide.ui.tests.git.framework.annotations.GitInput;
+import org.eclipse.emf.compare.ide.ui.tests.git.framework.annotations.GitMerge;
+import org.eclipse.jgit.api.Status;
+import org.eclipse.jgit.api.errors.JGitInternalException;
+import org.junit.runner.RunWith;
+
+@RunWith(GitTestRunner.class)
+@SuppressWarnings({"nls", })
+public class MultipleAncestorsTest {
+
+	/**
+	 * Three people modifying two 4 models: 1 model for each person and 1 "index" model that links the 4
+	 * together.
+	 * <p>
+	 * Each person is modifying a single ecore file, everyone on their own branch. However, they're all
+	 * merging to and from the same branch. There should never be a conflicting merge, but there will be
+	 * multiple ancestors for the merges.
+	 * </p>
+	 */
+	@GitInput("data/multipleancestors/complex.merge.zip")
+	@GitMerge(local = "assemblage", remote = "arthur")
+	public void testComplexMerge(Status status, List<IProject> projects) {
+		assertEquals(1, projects.size());
+		assertFilesExist(projects.get(0), "index.ecore", "Arthur.ecore", "Laurent.ecore", "Stephane.ecore");
+		assertTrue(status.getConflicting().isEmpty());
+		assertTrue(status.isClean());
+	}
+
+	/**
+	 * Two people modifying two models in their own branch, merging to and from master.
+	 * <p>
+	 * The two persons are modifying the same model files, but they're only creating "textual" conflicts (as
+	 * opposed to model conflicts). These are automatically mergeable through EMF Compare and this merge
+	 * should just finish correctly.
+	 * </p>
+	 */
+	@GitInput("data/multipleancestors/library.binaryecore.multiple.ancestors.conflicts.zip")
+	@GitMerge(local = "master", remote = "Stephane")
+	public void testLibraryTextualConflicts(Status status, List<IProject> projects) {
+		assertEquals(1, projects.size());
+		assertFilesExist(projects.get(0), "library.ecore", "types.ecore");
+		assertTrue(status.getConflicting().isEmpty());
+		assertTrue(status.isClean());
+	}
+
+	/**
+	 * Two people modifying two models in their own branch, merging to and from master, and using an
+	 * "assembly" branch to test before merging towards master.
+	 * <p>
+	 * The two persons have created a conflict in a previous merge, and have merged in such a way that there
+	 * is now a conflict in the two commits that need to be used to create a base ancestor. JGit cannot handle
+	 * that case and the merge is impossible.
+	 * </p>
+	 */
+	@GitInput("data/multipleancestors/conflict.base.ancestor.zip")
+	@GitMerge(local = "assemblage", remote = "arthur", expected = JGitInternalException.class)
+	public void testModelAndTextualConflictInBaseCommits(Status status, List<IProject> projects) {
+		assertEquals(1, projects.size());
+		assertFilesExist(projects.get(0), "library.uml", "types.uml");
+		assertTrue(status.getConflicting().isEmpty());
+		assertTrue(status.isClean());
+	}
+
+	/**
+	 * Two people modifying two models in their own branch, merging to and from master.
+	 * <p>
+	 * The two persons are modifying different files and will not have conflictual differences with each
+	 * other. This merge will go correctly.
+	 * </p>
+	 */
+	@GitInput("data/multipleancestors/library.binaryecore.multiple.ancestors.no.conflict.different.files.zip")
+	@GitMerge(local = "master", remote = "Stephane")
+	public void testLibraryNoConflicts(Status status, List<IProject> projects) {
+		assertEquals(1, projects.size());
+		assertFilesExist(projects.get(0), "library.ecore", "types.ecore");
+		assertTrue(status.getConflicting().isEmpty());
+		assertTrue(status.isClean());
+	}
+
+	/**
+	 * Asserts that all given files exist in the given project.
+	 * 
+	 * @param project
+	 *            project
+	 * @param files
+	 *            files that need to exist in the project
+	 */
+	protected void assertFilesExist(IProject project, String... files) {
+		for (String file : files) {
+			assertTrue(file + " does not exist.", project.getFile(file).exists());
+		}
+	}
+
+}
diff --git a/plugins/org.eclipse.emf.compare.ide.ui.tests.git/src/org/eclipse/emf/compare/ide/ui/tests/merge/data/multipleancestors/complex.merge.zip b/plugins/org.eclipse.emf.compare.ide.ui.tests.git/src/org/eclipse/emf/compare/ide/ui/tests/merge/data/multipleancestors/complex.merge.zip
new file mode 100644
index 000000000..fefa41efc
--- /dev/null
+++ b/plugins/org.eclipse.emf.compare.ide.ui.tests.git/src/org/eclipse/emf/compare/ide/ui/tests/merge/data/multipleancestors/complex.merge.zip
diff --git a/plugins/org.eclipse.emf.compare.ide.ui.tests.git/src/org/eclipse/emf/compare/ide/ui/tests/merge/data/multipleancestors/conflict.base.ancestor.zip b/plugins/org.eclipse.emf.compare.ide.ui.tests.git/src/org/eclipse/emf/compare/ide/ui/tests/merge/data/multipleancestors/conflict.base.ancestor.zip
new file mode 100644
index 000000000..8f2b4a2bd
--- /dev/null
+++ b/plugins/org.eclipse.emf.compare.ide.ui.tests.git/src/org/eclipse/emf/compare/ide/ui/tests/merge/data/multipleancestors/conflict.base.ancestor.zip
diff --git a/plugins/org.eclipse.emf.compare.ide.ui.tests.git/src/org/eclipse/emf/compare/ide/ui/tests/merge/data/multipleancestors/library.binaryecore.multiple.ancestors.conflicts.zip b/plugins/org.eclipse.emf.compare.ide.ui.tests.git/src/org/eclipse/emf/compare/ide/ui/tests/merge/data/multipleancestors/library.binaryecore.multiple.ancestors.conflicts.zip
new file mode 100644
index 000000000..65dbaa01c
--- /dev/null
+++ b/plugins/org.eclipse.emf.compare.ide.ui.tests.git/src/org/eclipse/emf/compare/ide/ui/tests/merge/data/multipleancestors/library.binaryecore.multiple.ancestors.conflicts.zip
diff --git a/plugins/org.eclipse.emf.compare.ide.ui.tests.git/src/org/eclipse/emf/compare/ide/ui/tests/merge/data/multipleancestors/library.binaryecore.multiple.ancestors.no.conflict.different.files.zip b/plugins/org.eclipse.emf.compare.ide.ui.tests.git/src/org/eclipse/emf/compare/ide/ui/tests/merge/data/multipleancestors/library.binaryecore.multiple.ancestors.no.conflict.different.files.zip
new file mode 100644
index 000000000..f3b396dd3
--- /dev/null
+++ b/plugins/org.eclipse.emf.compare.ide.ui.tests.git/src/org/eclipse/emf/compare/ide/ui/tests/merge/data/multipleancestors/library.binaryecore.multiple.ancestors.no.conflict.different.files.zip
diff --git a/plugins/org.eclipse.emf.compare.ide.ui.tests.git/src/org/eclipse/emf/compare/ide/ui/tests/suite/GitTests.java b/plugins/org.eclipse.emf.compare.ide.ui.tests.git/src/org/eclipse/emf/compare/ide/ui/tests/suite/GitTests.java
index 312b31393..19cb4bf5e 100644
--- a/plugins/org.eclipse.emf.compare.ide.ui.tests.git/src/org/eclipse/emf/compare/ide/ui/tests/suite/GitTests.java
+++ b/plugins/org.eclipse.emf.compare.ide.ui.tests.git/src/org/eclipse/emf/compare/ide/ui/tests/suite/GitTests.java
@@ -17,6 +17,7 @@ import org.eclipse.emf.compare.ide.ui.tests.merge.AdditiveMergeTests;
 import org.eclipse.emf.compare.ide.ui.tests.merge.DirCacheResourceVariantTreeProviderTest;
 import org.eclipse.emf.compare.ide.ui.tests.merge.EMFResourceMappingMergerPreMergeTest;
 import org.eclipse.emf.compare.ide.ui.tests.merge.GitResourceVariantTreeSubscriberTest;
+import org.eclipse.emf.compare.ide.ui.tests.merge.MultipleAncestorsTest;
 import org.eclipse.emf.compare.ide.ui.tests.merge.ResourceVariantTest;
 import org.eclipse.emf.compare.ide.ui.tests.merge.TreeWalkResourceVariantTreeProviderTest;
 import org.eclipse.emf.compare.ide.ui.tests.unit.GitLogicalModelTest;
@@ -57,7 +58,7 @@ import org.junit.runners.Suite.SuiteClasses;
 		// StrategyRecursiveModelTest.class,
 		// StrategyRecursiveModelWithDeepProjectTest.class,
 		ThreadedModelResolverResolutionTest.class, TreeWalkResourceVariantTreeProviderTest.class,
-		EMFResourceMappingMergerPreMergeTest.class })
+		EMFResourceMappingMergerPreMergeTest.class, MultipleAncestorsTest.class, })
 public class GitTests {
 
 	@BeforeClass