check if git is available on non-win32 platform

.moban.cd/changelog.yml

@@ -5,6 +5,7 @@ releases:
   - action: Removed
     details:
     - "`#253`: symbolic link in regression pack causes python setup.py to do recursive include"
+    - "`#209`: Alert moban user when `git` is not available and is used."
   date: unreleased
   version: 0.4.3
 - changes:

CHANGELOG.rst

@@ -9,6 +9,8 @@ Removed
 
 #. `#253 <https://github.com/moremoban/moban/issues/253>`_: symbolic link in
    regression pack causes python setup.py to do recursive include
+#. `#209 <https://github.com/moremoban/moban/issues/209>`_: Alert moban user
+   when `git` is not available and is used.
 
 0.4.2 - 08.03.2019
 --------------------------------------------------------------------------------

moban/exceptions.py

@@ -24,3 +24,7 @@ class IncorrectDataInput(Exception):
 
 class GroupTargetNotFound(Exception):
     pass
+
+
+class NoGitCommand(Exception):
+    pass

moban/repo.py

@@ -1,12 +1,20 @@
 import os
+import sys
+import subprocess
 
-from moban import reporter, constants
+from moban import reporter, constants, exceptions
 from moban.utils import mkdir_p
 
 
 def git_clone(requires):
     from git import Repo
 
+    if sys.platform != "win32":
+        # Unfortunately for windows user, the following function
+        # needs shell=True, which expose security risk. I would
+        # rather not to trade it with its marginal benefit
+        make_sure_git_is_available()
+
     moban_home = get_moban_home()
     mkdir_p(moban_home)
 
@@ -51,3 +59,10 @@ def get_moban_home():
 
     home_dir = user_cache_dir(appname=constants.PROGRAM_NAME)
     return os.path.join(home_dir, constants.MOBAN_REPOS_DIR_NAME)
+
+
+def make_sure_git_is_available():
+    try:
+        subprocess.check_output(["git", "--help"])
+    except Exception:
+        raise exceptions.NoGitCommand("Please install git command")

tests/mobanfile/test_targets.py

@@ -37,7 +37,7 @@ def test_handling_group_target():
 def test_extract_group_targets():
     test_targets = [
         {"output": "a.output", "template": "a.template.jj2"},
-        {"copy": [{"output": "source"}], "copy1": [{"output1": "source1"}]}
+        {"copy": [{"output": "source"}], "copy1": [{"output1": "source1"}]},
     ]
     actual = targets.extract_group_targets("copy1", test_targets)
     expected = [{"copy1": [{"output1": "source1"}]}]

tests/test_repo.py

@@ -1,9 +1,15 @@
 import os
 
 from mock import patch
-from nose.tools import eq_
+from nose.tools import eq_, raises
 
-from moban.repo import git_clone, get_repo_name, get_moban_home
+from moban.repo import (
+    git_clone,
+    get_repo_name,
+    get_moban_home,
+    make_sure_git_is_available,
+)
+from moban.exceptions import NoGitCommand
 from moban.definitions import GitRequire
 
 
@@ -112,3 +118,9 @@ def test_get_repo_name_can_handle_invalid_url(fake_reporter):
 def test_get_moban_home(_):
     actual = get_moban_home()
     eq_(os.path.join("root", "repos"), actual)
+
+
+@raises(NoGitCommand)
+@patch("subprocess.check_output", side_effect=Exception)
+def test_make_git_is_available(_):
+    make_sure_git_is_available()