Parse old mode and new mode lines properly

index.js

@@ -63,10 +63,11 @@
                                 break simiLoop;
 
                             case 'deleted':
+                            case 'old':
                             case 'new':
-                                var leftStr = simiLine.slice(spaceIndex + 1);
-                                if (leftStr.indexOf('file mode') === 0) {
-                                    currentInfo[infoType === 'new' ? 'newMode' : 'oldMode'] = leftStr.slice(10);
+                                var match = / mode (\d+)/.exec(simiLine);
+                                if (match) {
+                                    currentInfo[infoType === 'new' ? 'newMode' : 'oldMode'] = match[1];
                                 }
                                 break;
 

test/git.test.js

@@ -44,6 +44,16 @@ describe("git specific tests", () => {
         expect(file.newMode).toBe('100644');
     });
 
+    it("should have old and new modes", () => {
+        const diff = parse("chmod.diff");
+        const file = diff[0];
+        expect(file.type).toBe("modify");
+        expect(file.oldPath).toBe("a.txt");
+        expect(file.newPath).toBe("a.txt");
+        expect(file.oldMode).toBe('100644');
+        expect(file.newMode).toBe('100755');
+    });
+
     it("should parse filename correctly if whitespace included", () => {
         const diff = parse("edit-ws.diff");
         const file = diff[0];

test/git/chmod.diff

@@ -0,0 +1,9 @@
+diff --git a/a.txt b/a.txt
+old mode 100644
+new mode 100755
+index 7898192..7e8a165
+--- a/a.txt
++++ b/a.txt
+@@ -1 +1,2 @@
+ a
++a