Add ability to fetch merge commits

CHANGES

@@ -5,6 +5,13 @@
 Here you can see the list of changes between each git-pr release.
 
 
+0.2.0 (YYYY-MM-DD)
+==================
+
+- New argument: ``-m``, ``--merge``. The flag is used to fetch a merge
+  commit of a given pull request and ``master`` branch.
+
+
 0.1.0 (2015-10-17)
 ==================
 

git_pr/__init__.py

@@ -9,5 +9,5 @@
     :license: MIT, see LICENSE for details
 """
 
-__version__ = '0.1.0'
+__version__ = '0.2.0'
 __license__ = 'MIT'

git_pr/__main__.py

@@ -33,11 +33,15 @@ def main(args=sys.argv[1:]):
         '-b', '--branch',
         help='create a branch if passed')
 
+    parser.add_argument(
+        '-m', '--merge-commit', action='store_true',
+        help='fetch merge commit if passed')
+
     arguments = parser.parse_args(args)
 
     try:
         pr = PullRequest(arguments.repository)
-        pr.get(arguments.pull_request, arguments.branch)
+        pr.get(arguments.pull_request, arguments.branch, arguments.merge_commit)
     except subprocess.CalledProcessError:
         # do nothing, just because that mostly means we do have an error
         # from git binary on stderr and it makes no sense to continue or

git_pr/core.py

@@ -14,12 +14,31 @@
 
 
 class PullRequest(object):
+    """
+    A simple wrapper around Git to manage GitHub's pull requests.
+
+    The class allows you:
+
+    * to retrieve a pull request
+    * to retrieve a pull request's "merge" commit against "master" branch
+
+    :param repository: a Git URL or remote that points to some GitHub repo
+    """
 
     def __init__(self, repository):
         self._repository = repository
 
-    def get(self, pr, branch=None):
-        refspec = 'pull/{0}/head'.format(pr)
+    def get(self, pr, branch=None, merge_commit=False):
+        """
+        Retrieves pull request with ID = ``pr``.
+
+        :param pr: a pull request ID
+        :param branch: a branch to fetch into (if passed)
+        :param merge_commit: fetch merge commit, not pull request's head
+        """
+        pointer = 'head' if not merge_commit else 'merge'
+        refspec = 'refs/pull/{0}/{1}'.format(pr, pointer)
+
         if branch is not None:
             refspec = '{0}:{1}'.format(refspec, branch)
         subprocess.check_call(['git', 'fetch', self._repository, refspec])

man/git-pr.1

@@ -36,6 +36,11 @@ A pull request ID to be fetched.
 If passed, a pull request will be fetched into a new branch with a given
 \fIname\fR.
 
+.TP
+.B \-m, \-\-merge-commit
+If passed, a merge commit of pull request and master will be fetched.
+Please note, it's possible to fetch only a merge commit of open pull requests.
+
 
 .SH BUGS
 Bug reports can be submitted to <https://github.com/ikalnitsky/git\-pr/issues>

tests/test_core.py

@@ -19,20 +19,36 @@
 class TestPullRequest(unittest.TestCase):
 
     def setUp(self):
-        self.pr = PullRequest('test-repo')
+        self.pr = PullRequest('repo')
 
     def test_get(self, sp_call):
         self.pr.get(42)
 
         self.assertEqual([
-            mock.call(['git', 'fetch', 'test-repo', 'pull/42/head']),
+            mock.call(['git', 'fetch', 'repo', 'refs/pull/42/head']),
             mock.call(['git', 'checkout', 'FETCH_HEAD']),
         ], sp_call.call_args_list)
 
     def test_get_create_branch(self, sp_call):
         self.pr.get(42, 'pr/42')
 
         self.assertEqual([
-            mock.call(['git', 'fetch', 'test-repo', 'pull/42/head:pr/42']),
+            mock.call(['git', 'fetch', 'repo', 'refs/pull/42/head:pr/42']),
+            mock.call(['git', 'checkout', 'pr/42']),
+        ], sp_call.call_args_list)
+
+    def test_get_merge_commit(self, sp_call):
+        self.pr.get(42, merge_commit=True)
+
+        self.assertEqual([
+            mock.call(['git', 'fetch', 'repo', 'refs/pull/42/merge']),
+            mock.call(['git', 'checkout', 'FETCH_HEAD']),
+        ], sp_call.call_args_list)
+
+    def test_get_create_branch_and_merge_commit(self, sp_call):
+        self.pr.get(42, 'pr/42', merge_commit=True)
+
+        self.assertEqual([
+            mock.call(['git', 'fetch', 'repo', 'refs/pull/42/merge:pr/42']),
             mock.call(['git', 'checkout', 'pr/42']),
         ], sp_call.call_args_list)

tests/test_main.py

@@ -22,16 +22,22 @@ def test_one_argument(self, PullRequest):
         main(['42'])
 
         PullRequest.assert_called_once_with('origin')
-        PullRequest('origin').get.assert_called_once_with(42, None)
+        PullRequest('origin').get.assert_called_once_with(42, None, False)
 
     def test_two_arguments(self, PullRequest):
         main(['github', '42'])
 
         PullRequest.assert_called_once_with('github')
-        PullRequest('github').get.assert_called_once_with(42, None)
+        PullRequest('github').get.assert_called_once_with(42, None, False)
 
     def test_branch_argument(self, PullRequest):
         main(['42', '-b', 'pr/42'])
 
         PullRequest.assert_called_once_with('origin')
-        PullRequest('origin').get.assert_called_once_with(42, 'pr/42')
+        PullRequest('origin').get.assert_called_once_with(42, 'pr/42', False)
+
+    def test_merge_commit_argument(self, PullRequest):
+        main(['42', '-m'])
+
+        PullRequest.assert_called_once_with('origin')
+        PullRequest('origin').get.assert_called_once_with(42, None, True)