Add Repository.parse_diff to wrap git_diff_from_buffer

Author: brandonio21

src/repository.c

@@ -35,6 +35,7 @@
 #include "oid.h"
 #include "note.h"
 #include "repository.h"
+#include "diff.h"
 #include "branch.h"
 #include "signature.h"
 #include <git2/odb_backend.h>
@@ -1464,6 +1465,31 @@ Repository_create_reference_symbolic(Repository *self,  PyObject *args,
     return wrap_reference(c_reference, self);
 }
 
+PyDoc_STRVAR(Repository_parse_diff__doc__,
+  "parse_diff(git_diff: str) -> Diff\n"
+  "\n"
+  "Parses a git unified diff into a diff object applied to the repository");
+
+PyObject *
+Repository_parse_diff(PyObject *self, PyObject *args)
+{
+  /* A wrapper around
+   * git_diff_from_buffer
+  */
+  git_diff *diff;
+  const char *content = NULL;
+  Py_ssize_t content_len;
+  int err;
+
+  if (!PyArg_ParseTuple(args, "s#", &content, &content_len))
+    return NULL;
+
+  err = git_diff_from_buffer(&diff, content, content_len);
+  if (err < 0)
+    return Error_set(err);
+
+  return wrap_diff(diff, (Repository *) self);
+}
 
 PyDoc_STRVAR(Repository_status__doc__,
   "status() -> {str: int}\n"
@@ -1813,6 +1839,7 @@ PyMethodDef Repository_methods[] = {
     METHOD(Repository, init_submodules, METH_VARARGS | METH_KEYWORDS),
     METHOD(Repository, lookup_reference, METH_O),
     METHOD(Repository, revparse_single, METH_O),
+    METHOD(Repository, parse_diff, METH_VARARGS),
     METHOD(Repository, status, METH_NOARGS),
     METHOD(Repository, status_file, METH_O),
     METHOD(Repository, notes, METH_VARARGS),

test/test_repository.py

@@ -35,6 +35,7 @@
 import binascii
 import unittest
 import tempfile
+import textwrap
 import os
 from os.path import join, realpath
 import sys
@@ -196,6 +197,45 @@ def test_hash(self):
         written_sha1 = self.repo.create_blob(data)
         self.assertEqual(hashed_sha1, written_sha1)
 
+    def test_parse_diff_null(self):
+        with self.assertRaises(Exception):
+            self.repo.parse_diff(None)
+
+    def test_parse_diff_bad(self):
+        diff = textwrap.dedent(
+        """
+        diff --git a/file1 b/file1
+        old mode 0644
+        new mode 0644
+        @@ -1,1 +1,1 @@
+        -Hi!
+        """)
+        with self.assertRaises(Exception):
+            self.repo.parse_diff(diff)
+
+    def test_parse_diff(self):
+        diff = textwrap.dedent(
+        """
+        diff --git a/file1 b/file1
+        old mode 0644
+        new mode 0644
+        @@ -1,1 +1,1 @@
+        -Hello, world!
+        +Hola, Mundo!
+        """
+        )
+        git_diff = self.repo.parse_diff(diff)
+        stats = git_diff.stats
+        deltas = list(git_diff.deltas)
+
+        self.assertEqual(1, stats.deletions)
+        self.assertEqual(1, stats.insertions)
+        self.assertEqual(1, stats.files_changed)
+
+        self.assertEqual(1, len(deltas))
+        self.assertEqual("file1", deltas[0].old_file.path)
+        self.assertEqual("file1", deltas[0].new_file.path)
+
     def test_hashfile(self):
         data = "bazbarfoo"
         handle, tempfile_path = tempfile.mkstemp()