Add a test for the command line

2 files changed, 23 insertions, 4 deletions

diff --git a/isort/main.py b/isort/main.py
index 9356c6a3..28e8974a 100644
--- a/isort/main.py
+++ b/isort/main.py
@@ -172,7 +172,7 @@ class ISortCommand(setuptools.Command):
             exit(1)
 
 
-def create_parser():
+def parse_args(argv=None):
     parser = argparse.ArgumentParser(description='Sort Python import definitions alphabetically '
                                                  'within logical sections.')
     inline_args_group = parser.add_mutually_exclusive_group()
@@ -287,14 +287,14 @@ def create_parser():
                         help='Tells isort to apply changes recursively without asking')
     parser.add_argument('files', nargs='*', help='One or more Python source files that need their imports sorted.')
 
-    arguments = {key: value for key, value in vars(parser.parse_args()).items() if value}
+    arguments = {key: value for key, value in vars(parser.parse_args(argv)).items() if value}
     if 'dont_order_by_type' in arguments:
         arguments['order_by_type'] = False
     return arguments
 
 
-def main():
-    arguments = create_parser()
+def main(argv=None):
+    arguments = parse_args(argv)
     if arguments.get('show_version'):
         print(INTRO)
         return
diff --git a/test_isort.py b/test_isort.py
index ce889628..3cb3070a 100644
--- a/test_isort.py
+++ b/test_isort.py
@@ -2596,3 +2596,22 @@ def test_monkey_patched_urllib():
         # Previous versions of isort monkey patched urllib which caused unusual
         # importing for other projects.
         from urllib import quote  # noqa: F401
+
+
+def test_argument_parsing():
+    from isort.main import parse_args
+    args = parse_args(['-dt', '-t', 'foo', '--skip=bar', 'baz.py'])
+    assert args['order_by_type'] is False
+    assert args['force_to_top'] == ['foo']
+    assert args['skip'] == ['bar']
+    assert args['files'] == ['baz.py']
+
+
+def test_command_line(tmpdir, capsys):
+    from isort.main import main
+    tmpdir.join("file.py").write("import re\nimport os\n\nimport contextlib\n\n\nimport isort")
+    main(["-rc", str(tmpdir)])
+    assert tmpdir.join("file.py").read() == "import contextlib\nimport os\nimport re\n\nimport isort\n"
+    out, err = capsys.readouterr()
+    assert not err
+    assert str(tmpdir.join("file.py")) in out  # it informs us about fixing