Add helper methods to Edit

Exposing isEmpty, getLengthA, getLengthB make it easier to examine
the state of an edit and work with it from higher level code.

The before and after cut routines make it easy to split an edit
that contains another edit, such as to decompose a REPLACE that
contains a common sequence within it.

Change-Id: Id63d6476a7a6b23acb7ab237d414a0a1a7200290
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

1 files changed, 24 insertions, 1 deletions

diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/diff/EditTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/diff/EditTest.java
index 6f3d21e558..598e6d2b67 100644
--- a/org.eclipse.jgit.test/tst/org/eclipse/jgit/diff/EditTest.java
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/diff/EditTest.java
@@ -61,6 +61,8 @@ public class EditTest extends TestCase {
 		assertEquals(1, e.getEndA());
 		assertEquals(3, e.getBeginB());
 		assertEquals(3, e.getEndB());
+		assertTrue("is empty", e.isEmpty());
+		assertSame(Edit.Type.EMPTY, e.getType());
 	}
 
 	public void testSwap() {
@@ -75,21 +77,34 @@ public class EditTest extends TestCase {
 	public void testType_Insert() {
 		final Edit e = new Edit(1, 1, 1, 2);
 		assertSame(Edit.Type.INSERT, e.getType());
+		assertFalse("not empty", e.isEmpty());
+		assertEquals(0, e.getLengthA());
+		assertEquals(1, e.getLengthB());
 	}
 
 	public void testType_Delete() {
 		final Edit e = new Edit(1, 2, 1, 1);
 		assertSame(Edit.Type.DELETE, e.getType());
+		assertFalse("not empty", e.isEmpty());
+		assertEquals(1, e.getLengthA());
+		assertEquals(0, e.getLengthB());
 	}
 
 	public void testType_Replace() {
 		final Edit e = new Edit(1, 2, 1, 4);
 		assertSame(Edit.Type.REPLACE, e.getType());
+		assertFalse("not empty", e.isEmpty());
+		assertEquals(1, e.getLengthA());
+		assertEquals(3, e.getLengthB());
 	}
 
 	public void testType_Empty() {
-		assertSame(Edit.Type.EMPTY, new Edit(1, 1, 2, 2).getType());
+		final Edit e = new Edit(1, 1, 2, 2);
+		assertSame(Edit.Type.EMPTY, e.getType());
 		assertSame(Edit.Type.EMPTY, new Edit(1, 2).getType());
+		assertTrue("is empty", e.isEmpty());
+		assertEquals(0, e.getLengthA());
+		assertEquals(0, e.getLengthB());
 	}
 
 	public void testToString() {
@@ -143,4 +158,12 @@ public class EditTest extends TestCase {
 		e.extendB();
 		assertEquals(new Edit(1, 2, 1, 3), e);
 	}
+
+	public void testBeforeAfterCuts() {
+		final Edit whole = new Edit(1, 8, 2, 9);
+		final Edit mid = new Edit(4, 5, 3, 6);
+
+		assertEquals(new Edit(1, 4, 2, 3), whole.before(mid));
+		assertEquals(new Edit(5, 8, 6, 9), whole.after(mid));
+	}
 }