Add an integration test for missing user.name and user.email

We test the behavior when these variables are completely missing by
setting the GIT_CONFIG environment variable. This requires adding a
mechanism to pass through the _env variable to the `sh` library. We
keep the existing process's environment to allow things like
virtualenvs to work.

qa/base.py

@@ -93,6 +93,13 @@ def create_file(parent_dir):
         io.open(os.path.join(parent_dir, test_filename), 'a', encoding=DEFAULT_ENCODING).close()
         return test_filename
 
+    def create_tmp_git_config(self, contents):
+        """ Creates an environment with the GIT_CONFIG variable set to a file with the given contents. """
+        tmp_config = self.create_tmpfile(contents)
+        env = os.environ.copy()
+        env["GIT_CONFIG"] = tmp_config
+        return env
+
     def create_simple_commit(self, message, out=None, ok_code=None, env=None, git_repo=None, tty_in=False):
         """ Creates a simple commit with an empty test file.
             :param message: Commit message for the commit. """

qa/shell.py

@@ -67,6 +67,8 @@ def _exec(*args, **kwargs):
         popen_kwargs = {'stdout': pipe, 'stderr': pipe, 'shell': kwargs.get('_tty_out', False)}
         if '_cwd' in kwargs:
             popen_kwargs['cwd'] = kwargs['_cwd']
+        if '_env' in kwargs:
+            popen_kwargs['env'] = kwargs['_env']
 
         try:
             p = subprocess.Popen(args, **popen_kwargs)

qa/test_gitlint.py

@@ -157,6 +157,28 @@ def test_msg_filename_no_tty(self):
 
         self.assertEqualStdout(output, self.get_expected("test_gitlint/test_msg_filename_no_tty_1"))
 
+    def test_no_git_name_set(self):
+        """ Ensure we print out a helpful message if user.name is not set """
+        tmp_commit_msg_file = self.create_tmpfile(u"WIP: msg-fïlename NO name test.")
+        # Name is checked before email so this isn't strictly
+        # necessary but seems good for consistency.
+        env = self.create_tmp_git_config(u"[user]\n  email = test-emåil@foo.com\n")
+        output = gitlint("--staged", "--msg-filename", tmp_commit_msg_file,
+                         _ok_code=[self.GIT_CONTEXT_ERROR_CODE],
+                         _env=env)
+        expected = u"Missing git configuration: please set user.name\n"
+        self.assertEqualStdout(output, expected)
+
+    def test_no_git_email_set(self):
+        """ Ensure we print out a helpful message if user.email is not set """
+        tmp_commit_msg_file = self.create_tmpfile(u"WIP: msg-fïlename NO email test.")
+        env = self.create_tmp_git_config(u"[user]\n  name = test åuthor\n")
+        output = gitlint("--staged", "--msg-filename", tmp_commit_msg_file,
+                         _ok_code=[self.GIT_CONTEXT_ERROR_CODE],
+                         _env=env)
+        expected = u"Missing git configuration: please set user.email\n"
+        self.assertEqualStdout(output, expected)
+
     def test_git_errors(self):
         # Repo has no commits: caused by `git log`
         empty_git_repo = self.create_tmp_git_repo()