Merge pull request #855 from dterror/setting-script-path-fix

First arg is script_path unless explicitly set

Author: David Marin

mrjob/launch.py

@@ -368,12 +368,12 @@ def _process_args(self, args):
         uses all args as input files. This method determines the behavior:
         MRJobLauncher takes off the first arg as the script path.
         """
-        if self._script_path:
-            self._script_path = os.path.abspath(args[0])
-        elif len(args) < 1:
-            self.option_parser.error('Must supply script path')
-
-        self.args = args[1:]
+        if not self._script_path:
+            if len(args) < 1:
+                self.option_parser.error('Must supply script path')
+            else:
+                self._script_path = os.path.abspath(args[0])
+                self.args = args[1:]
 
     def _help_main(self):
         self.option_parser.option_groups = []

tests/test_launch.py

@@ -278,3 +278,7 @@ def test_no_conf_overrides(self):
     def test_no_conf_overridden(self):
         mr_job = MRCustomJobLauncher(args=['', '--no-conf', '-c', 'blah.conf'])
         self.assertEqual(mr_job.options.conf_paths, ['blah.conf'])
+
+    def test_requires_script_path(self):
+        self.assertRaises(ValueError, MRCustomJobLauncher, args=[])
+