Parse modes from git diffs

__tests__/parse.spec.js

@@ -28,6 +28,8 @@ index 123..456 789
     const file = files[0];
     expect(file.from).toBe("file");
     expect(file.to).toBe("file");
+    expect(file.oldMode).toBe("789");
+    expect(file.newMode).toBe("789");
     expect(file.deletions).toBe(1);
     expect(file.additions).toBe(1);
     expect(file.chunks.length).toBe(1);
@@ -85,6 +87,8 @@ Binary files a/Artsy_Tests/ReferenceImages/ARTopMenuViewControllerSpec/selects '
     expect(file.to).toBe(
       "Artsy_Tests/ReferenceImages/ARTopMenuViewControllerSpec/selects 'home' by default as ipad@2x.png"
     );
+    expect(file.oldMode).toBe("100644");
+    expect(file.newMode).toBe("100644");
   });
 
   it("should parse diff with new file mode line", function () {
@@ -102,6 +106,7 @@ index 0000000..db81be4
     expect(files.length).toBe(1);
     const file = files[0];
     expect(file.new).toBeTruthy();
+    expect(file.newMode).toBe("100644");
     expect(file.from).toBe("/dev/null");
     expect(file.to).toBe("test");
     expect(file.chunks[0].content).toBe("@@ -0,0 +1,2 @@");
@@ -125,6 +130,7 @@ index db81be4..0000000
     expect(files.length).toBe(1);
     const file = files[0];
     expect(file.deleted).toBeTruthy();
+    expect(file.oldMode).toBe("100644");
     expect(file.from).toBe("test");
     expect(file.to).toBe("/dev/null");
     expect(file.chunks[0].content).toBe("@@ -1,2 +0,0 @@");
@@ -133,6 +139,35 @@ index db81be4..0000000
     expect(file.chunks[0].changes[1].content).toBe("-line2");
   });
 
+  it("should parse diff with old and new mode lines", function () {
+    const diff = `\
+diff --git a/file b/file
+old mode 100644
+new mode 100755
+index 123..456
+--- a/file
++++ b/file
+@@ -1,2 +1,2 @@
+- line1
++ line2\
+`;
+    const files = parse(diff);
+    expect(files.length).toBe(1);
+    const file = files[0];
+    expect(file.oldMode).toBe("100644");
+    expect(file.newMode).toBe("100755");
+    expect(file.from).toBe("file");
+    expect(file.to).toBe("file");
+    expect(file.deletions).toBe(1);
+    expect(file.additions).toBe(1);
+    expect(file.chunks.length).toBe(1);
+    const chunk = file.chunks[0];
+    expect(chunk.content).toBe("@@ -1,2 +1,2 @@");
+    expect(chunk.changes.length).toBe(2);
+    expect(chunk.changes[0].content).toBe("- line1");
+    expect(chunk.changes[1].content).toBe("+ line2");
+  });
+
   it("should parse diff with single line files", function () {
     const diff = `\
 diff --git a/file1 b/file1
@@ -154,6 +189,7 @@ index 0000000..db81be4
     expect(files.length).toBe(2);
     let file = files[0];
     expect(file.deleted).toBeTruthy();
+    expect(file.oldMode).toBe("100644");
     expect(file.from).toBe("file1");
     expect(file.to).toBe("/dev/null");
     expect(file.chunks[0].content).toBe("@@ -1 +0,0 @@");
@@ -162,6 +198,7 @@ index 0000000..db81be4
     expect(file.chunks[0].changes[0].type).toBe("del");
     file = files[1];
     expect(file.new).toBeTruthy();
+    expect(file.newMode).toBe("100644");
     expect(file.from).toBe("/dev/null");
     expect(file.to).toBe("file2");
     expect(file.chunks[0].content).toBe("@@ -0,0 +1 @@");
@@ -196,13 +233,17 @@ index 123..456 789
     let file = files[0];
     expect(file.from).toBe("file1");
     expect(file.to).toBe("file1");
+    expect(file.oldMode).toBe("789");
+    expect(file.newMode).toBe("789");
     expect(file.chunks[0].content).toBe("@@ -1,1 +1,1 @@");
     expect(file.chunks[0].changes.length).toBe(2);
     expect(file.chunks[0].changes[0].content).toBe("- line1");
     expect(file.chunks[0].changes[1].content).toBe("+ line2");
     file = files[1];
     expect(file.from).toBe("file2");
     expect(file.to).toBe("file2");
+    expect(file.oldMode).toBe("789");
+    expect(file.newMode).toBe("789");
     expect(file.chunks[0].content).toBe("@@ -1,1 +1,1 @@");
     expect(file.chunks[0].changes.length).toBe(2);
     expect(file.chunks[0].changes[0].content).toBe("- line1");
@@ -226,6 +267,8 @@ index 123..456 789
     const file = files[0];
     expect(file.from).toBe("file1");
     expect(file.to).toBe("file1");
+    expect(file.oldMode).toBe("789");
+    expect(file.newMode).toBe("789");
     const chunk = file.chunks[0];
     expect(chunk.content).toBe("@@ -1,1 +1,1 @@");
     expect(chunk.changes.length).toBe(4);
@@ -343,6 +386,7 @@ index 0000000..e6a2e28\
     const file = files[0];
     expect(file.from).toBe("/dev/null");
     expect(file.to).toBe("newFile.txt");
+    expect(file.newMode).toBe("100644");
   });
 
   it("should parse file names for a deleted file", function () {
@@ -356,6 +400,7 @@ index e6a2e28..0000000\
     const file = files[0];
     expect(file.from).toBe("deletedFile.txt");
     expect(file.to).toBe("/dev/null");
+    expect(file.oldMode).toBe("100644");
   });
 
   it("should parse rename diff with space in path with no changes", function () {
@@ -411,6 +456,8 @@ index 9daeafb..88bd214 100644
     const [file] = files;
     expect(file.from).toBe(`file \\"space\\"`);
     expect(file.to).toBe(`file \\"space\\"`);
+    expect(file.oldMode).toBe("100644");
+    expect(file.newMode).toBe("100644");
   });
 
   it("should parse files with additional '-' and '+'", function () {
@@ -438,10 +485,14 @@ index 123..456 789
 
     expect(file1.from).toBe(`file1`);
     expect(file1.to).toBe(`file1`);
+    expect(file1.oldMode).toBe("789");
+    expect(file1.newMode).toBe("789");
     expect(file1.chunks[0].changes.length).toBe(3);
 
     expect(file2.from).toBe(`file2`);
     expect(file2.to).toBe(`file2`);
+    expect(file2.oldMode).toBe("789");
+    expect(file2.newMode).toBe("789");
     expect(file2.chunks[0].changes.length).toBe(3);
   });
 });

index.d.ts

@@ -7,6 +7,8 @@ declare namespace parseDiff {
     additions: number;
     from?: string;
     to?: string;
+    oldMode?: string;
+    newMode?: string;
     index?: string[];
     deleted?: true;
     new?: true;