Isolate globals in import sanity test.

test/sanity/import/importer.py

@@ -3,6 +3,12 @@
 from __future__ import (absolute_import, division, print_function)
 __metaclass__ = type
 
+
+def main():
+    """
+    Main program function used to isolate globals from imported code.
+    Changes to globals in imported modules on Python 2.7 will overwrite our own globals.
+    """
     import contextlib
     import os
     import re
@@ -30,17 +36,14 @@ try:
     except ImportError:
         AnsibleCollectionLoader = None
 
-
     class ImporterAnsibleModuleException(Exception):
         """Exception thrown during initialization of ImporterAnsibleModule."""
 
-
     class ImporterAnsibleModule:
         """Replacement for AnsibleModule to support import testing."""
         def __init__(self, *args, **kwargs):
             raise ImporterAnsibleModuleException()
 
-
     # stop Ansible module execution during AnsibleModule instantiation
     ansible.module_utils.basic.AnsibleModule = ImporterAnsibleModule
     # no-op for _load_params since it may be called before instantiating AnsibleModule
@@ -48,8 +51,7 @@ ansible.module_utils.basic._load_params = lambda *args, **kwargs: {}  # pylint:
     # no-op for removed_module since it is called in place of AnsibleModule instantiation
     ansible.module_utils.common.removed.removed_module = lambda *args, **kwargs: None
 
-
-def main():
+    def run():
         """Main program function."""
         base_dir = os.getcwd()
         messages = set()
@@ -65,7 +67,6 @@ def main():
         if messages:
             exit(10)
 
-
     def test_python_module(path, base_dir, messages, ansible_module):
         if ansible_module:
             # importing modules with __main__ under Python 2.6 exits with status code 1
@@ -149,7 +150,6 @@ def test_python_module(path, base_dir, messages, ansible_module):
 
             report_message(error, messages)
 
-
     class Capture:
         """Captured output and/or exception."""
         def __init__(self):
@@ -157,7 +157,6 @@ class Capture:
             self.stderr = StringIO()
             self.warnings = []
 
-
     def capture_report(path, capture, messages):
         """Report on captured output.
         :type path: str
@@ -198,7 +197,6 @@ def capture_report(path, capture, messages):
             message = '%s:%d:%d: %s: %s' % (filepath, lineno, 0, warning.category.__name__, msg)
             report_message(message, messages)
 
-
     def report_message(message, messages):
         """Report message if not already reported.
         :type message: str
@@ -208,7 +206,6 @@ def report_message(message, messages):
             messages.add(message)
             print(message)
 
-
     @contextlib.contextmanager
     def capture_output(capture):
         """Capture sys.stdout and sys.stderr.
@@ -229,6 +226,8 @@ def capture_output(capture):
                 sys.stdout = old_stdout
                 sys.stderr = old_stderr
 
+    run()
+
 
 if __name__ == '__main__':
     main()