added version command line argument

icontract_lint/main.py

@@ -9,6 +9,7 @@
 from typing import List, Any, TextIO
 
 import icontract_lint
+import pyicontract_lint_meta
 
 
 class Args:
@@ -19,17 +20,19 @@ def __init__(self, args: Any) -> None:
         assert isinstance(args.paths, list)
         assert all(isinstance(pth, str) for pth in args.paths)
 
+        self.dont_panic = bool(args.dont_panic)
         self.format = str(args.format)
+        self.version = bool(args.version)
         self.paths = [pathlib.Path(pth) for pth in args.paths]
-        self.dont_panic = bool(args.dont_panic)
 
 
 def parse_args(sys_argv: List[str]) -> Args:
     """Parse command-line arguments."""
     parser = argparse.ArgumentParser(description=__doc__)
     parser.add_argument("--dont_panic", help="Retrun a zero code even if there were errors.", action='store_true')
     parser.add_argument("--format", help="Specify the output format.", default='verbose', choices=['verbose', 'json'])
-    parser.add_argument("paths", help="Specify paths to check (directories and files).", nargs="+")
+    parser.add_argument("--version", help="Display the version and return immediately", action='store_true')
+    parser.add_argument("paths", help="Specify paths to check (directories and files).", nargs="*")
 
     args = parser.parse_args(sys_argv[1:])
 
@@ -38,6 +41,10 @@ def parse_args(sys_argv: List[str]) -> Args:
 
 def _main(args: Args, stream: TextIO) -> int:
     """Execute the main routine."""
+    if args.version:
+        stream.write("{}\n".format(pyicontract_lint_meta.__version__))
+        return 0
+
     errors = icontract_lint.check_paths(paths=args.paths)
 
     if args.format == 'verbose':

tests/test_main.py

@@ -12,6 +12,7 @@
 import icontract_lint.main
 
 # pylint: disable=missing-docstring
+import pyicontract_lint_meta
 
 
 class TestParseArgs(unittest.TestCase):
@@ -125,6 +126,15 @@ def test_dont_panic(self):
 
                 self.assertEqual(0, retcode)
 
+    def test_version(self):
+        buf = io.StringIO()
+        stream = cast(TextIO, buf)
+        args = icontract_lint.main.parse_args(sys_argv=["some-executable.py", "--version"])
+
+        retcode = icontract_lint.main._main(args=args, stream=stream)
+        self.assertEqual(0, retcode)
+        self.assertEqual('{}\n'.format(pyicontract_lint_meta.__version__), buf.getvalue())
+
 
 if __name__ == '__main__':
     unittest.main()