minor : Added test in GitDiffWithContextSizeDefault for addition of new file

Author: MiriyalaJayanth-19

src/test/java/com/puppycrawl/tools/checkstyle/jgit/GitDiffWithContextSizeDefaultTest.java

@@ -225,6 +225,26 @@ public void testInsertDeleteReplaceEditTypesWithinHunk() throws IOException {
         assertEquals(Edit.Type.DELETE, edits.get(2).getType());
     }
 
+    @Test
+    public void testNewFileAdded() throws Exception {
+        final String patchName = "AddedOneNewFile.patch";
+        final Patch patch = loadPatch(getPatchPath(patchName));
+        assertNotNull(patch);
+
+        final List<? extends FileHeader> fileHeaders = patch.getFiles();
+        assertEquals(1, fileHeaders.size());
+
+        // file header 0
+        assertEquals(FileHeader.PatchType.UNIFIED, fileHeaders.get(0).getPatchType());
+        assertEquals(1, fileHeaders.get(0).getHunks().size());
+        assertEquals("ADD", fileHeaders.get(0).getChangeType().name());
+
+        final EditList edits = fileHeaders.get(0).toEditList();
+        assertEquals(1, edits.size());
+        assertEquals(new Edit(-1, -1, 0, 6), edits.get(0));
+        assertEquals(Edit.Type.INSERT, edits.get(0).getType());
+    }
+
     @Override
     protected String getPatchPath(String patchName) {
         return CONTEXT_SIZE_DEFAULT_DIR + patchName;

src/test/resources/com/puppycrawl/tools/checkstyle/jgit/gitdiff/context-size-default/AddedOneNewFile.patch

@@ -0,0 +1,12 @@
+diff --git a/src/main/java/testAddFile.java b/src/main/java/testAddFile.java
+new file mode 100644
+index 0000000..e69de29
+--- /dev/null
++++ b/src/main/java/testAddFile.java
+@@ -0,0 +1,6 @@
++public class testAddFile {
++
++    public void hello() {
++        System.out.println("Hello World");
++    }
++}