Added more test cases for RenameDetector

I added test cases to cover the majority of the code. It's not 100%
coverage yet, but the remaining bits are small.

Change-Id: Ib534c8e94b13358b8b22cf54e2ff84132bae6d14

org.eclipse.jgit.test/tst/org/eclipse/jgit/diff/RenameDetectorTest.java

@@ -54,6 +54,7 @@ import org.eclipse.jgit.lib.RepositoryTestCase;
 
 public class RenameDetectorTest extends RepositoryTestCase {
 	private static final String PATH_A = "src/A";
+	private static final String PATH_B = "src/B";
 	private static final String PATH_H = "src/H";
 	private static final String PATH_Q = "src/Q";
 
@@ -109,8 +110,8 @@ public class RenameDetectorTest extends RepositoryTestCase {
 		DiffEntry a = DiffEntry.add(PATH_A, foo);
 		DiffEntry b = DiffEntry.delete(PATH_Q, foo);
 
-		DiffEntry c = DiffEntry.add("README", bar);
+		DiffEntry c = DiffEntry.add(PATH_H, bar);
-		DiffEntry d = DiffEntry.delete("REEDME", bar);
+		DiffEntry d = DiffEntry.delete(PATH_B, bar);
 
 		rd.add(a);
 		rd.add(b);
@@ -119,8 +120,30 @@ public class RenameDetectorTest extends RepositoryTestCase {
 
 		List<DiffEntry> entries = rd.compute();
 		assertEquals(2, entries.size());
-		assertRename(d, c, 100, entries.get(0));
+		assertRename(b, a, 100, entries.get(0));
-		assertRename(b, a, 100, entries.get(1));
+		assertRename(d, c, 100, entries.get(1));
+	}
+
+	public void testExactRename_MultipleIdenticalDeletes() throws Exception {
+		ObjectId foo = blob("foo");
+
+		DiffEntry a = DiffEntry.delete(PATH_A, foo);
+		DiffEntry b = DiffEntry.delete(PATH_B, foo);
+
+		DiffEntry c = DiffEntry.delete(PATH_H, foo);
+		DiffEntry d = DiffEntry.add(PATH_Q, foo);
+
+		rd.add(a);
+		rd.add(b);
+		rd.add(c);
+		rd.add(d);
+
+		// Pairs the add with the first delete added
+		List<DiffEntry> entries = rd.compute();
+		assertEquals(3, entries.size());
+		assertEquals(b, entries.get(0));
+		assertEquals(c, entries.get(1));
+		assertRename(a, d, 100, entries.get(2));
 	}
 
 	public void testInexactRename_OnePair() throws Exception {
@@ -146,8 +169,8 @@ public class RenameDetectorTest extends RepositoryTestCase {
 
 		ObjectId cId = blob("some\nsort\nof\ntext\n");
 		ObjectId dId = blob("completely\nunrelated\ntext\n");
-		DiffEntry c = DiffEntry.add("c", cId);
+		DiffEntry c = DiffEntry.add(PATH_B, cId);
-		DiffEntry d = DiffEntry.delete("d", dId);
+		DiffEntry d = DiffEntry.delete(PATH_H, dId);
 
 		rd.add(a);
 		rd.add(b);
@@ -156,9 +179,9 @@ public class RenameDetectorTest extends RepositoryTestCase {
 
 		List<DiffEntry> entries = rd.compute();
 		assertEquals(3, entries.size());
-		assertSame(c, entries.get(0));
+		assertRename(b, a, 66, entries.get(0));
-		assertSame(d, entries.get(1));
+		assertSame(c, entries.get(1));
-		assertRename(b, a, 66, entries.get(2));
+		assertSame(d, entries.get(2));
 	}
 
 	public void testInexactRename_LastByteDifferent() throws Exception {
@@ -176,6 +199,21 @@ public class RenameDetectorTest extends RepositoryTestCase {
 		assertRename(b, a, 88, entries.get(0));
 	}
 
+	public void testInexactRename_NewlinesOnly() throws Exception {
+		ObjectId aId = blob("\n\n\n");
+		ObjectId bId = blob("\n\n\n\n");
+
+		DiffEntry a = DiffEntry.add(PATH_A, aId);
+		DiffEntry b = DiffEntry.delete(PATH_Q, bId);
+
+		rd.add(a);
+		rd.add(b);
+
+		List<DiffEntry> entries = rd.compute();
+		assertEquals(1, entries.size());
+		assertRename(b, a, 74, entries.get(0));
+	}
+
 	public void testInexactRenames_OnePair2() throws Exception {
 		ObjectId aId = blob("ab\nab\nab\nac\nad\nae\n");
 		ObjectId bId = blob("ac\nab\nab\nab\naa\na0\na1\n");
@@ -267,6 +305,67 @@ public class RenameDetectorTest extends RepositoryTestCase {
 		assertSame(b, entries.get(1));
 	}
 
+	public void testNoRenames_SymlinkAndFileSamePath() throws Exception {
+		ObjectId aId = blob("src/dest");
+
+		DiffEntry a = DiffEntry.delete(PATH_A, aId);
+		DiffEntry b = DiffEntry.add(PATH_A, aId);
+		a.oldMode = FileMode.SYMLINK;
+
+		rd.add(a);
+		rd.add(b);
+
+		// Deletes should be first
+		List<DiffEntry> entries = rd.compute();
+		assertEquals(2, entries.size());
+		assertSame(a, entries.get(0));
+		assertSame(b, entries.get(1));
+	}
+
+	public void testSetRenameScore_IllegalArgs() throws Exception {
+		try {
+			rd.setRenameScore(-1);
+			fail();
+		} catch (IllegalArgumentException e) {
+			// pass
+		}
+
+		try {
+			rd.setRenameScore(101);
+			fail();
+		} catch (IllegalArgumentException e) {
+			// pass
+		}
+	}
+
+	public void testRenameLimit() throws Exception {
+		ObjectId aId = blob("foo\nbar\nbaz\nblarg\n");
+		ObjectId bId = blob("foo\nbar\nbaz\nblah\n");
+		DiffEntry a = DiffEntry.add(PATH_A, aId);
+		DiffEntry b = DiffEntry.delete(PATH_B, bId);
+
+		ObjectId cId = blob("a\nb\nc\nd\n");
+		ObjectId dId = blob("a\nb\nc\n");
+		DiffEntry c = DiffEntry.add(PATH_H, cId);
+		DiffEntry d = DiffEntry.delete(PATH_Q, dId);
+
+		rd.add(a);
+		rd.add(b);
+		rd.add(c);
+		rd.add(d);
+
+		rd.setRenameLimit(1);
+
+		assertTrue(rd.isOverRenameLimit());
+
+		List<DiffEntry> entries = rd.compute();
+		assertEquals(4, entries.size());
+		assertSame(a, entries.get(0));
+		assertSame(b, entries.get(1));
+		assertSame(c, entries.get(2));
+		assertSame(d, entries.get(3));
+	}
+
 	private ObjectId blob(String content) throws Exception {
 		return testDb.blob(content).copy();
 	}