Check if string_names is None before returning string_names (#1708)

* Check if string is None before using string_names

* Add test asserting None string_names returns an empty list

* Remove whitespace to pass flake8

* Add name to authors.txt

Co-authored-by: Leo Ryu <leo@episci.com>

AUTHORS.txt

@@ -60,6 +60,7 @@ Code Contributors
 - Max Mäusezahl (@mmaeusezahl) <maxmaeusezahl@googlemail.com>
 - Vladislav Serebrennikov (@endilll)
 - Andrii Kolomoiets (@muffinmad)
+- Leo Ryu (@Leo-Ryu)
 
 And a few more "anonymous" contributors.
 

jedi/inference/value/module.py

@@ -179,6 +179,9 @@ def is_package(self):
         return self._is_package
 
     def py__package__(self):
+        if self.string_names is None:
+            return []
+
         if self._is_package:
             return self.string_names
         return self.string_names[:-1]

test/test_inference/test_imports.py

@@ -96,6 +96,9 @@ def test_correct_zip_package_behavior(Script, inference_state, environment, code
     if path is not None:
         assert value.py__path__() == [str(pkg_zip_path.joinpath(path))]
 
+    value.string_names = None
+    assert value.py__package__() == []
+
 
 def test_find_module_not_package_zipped(Script, inference_state, environment):
     path = get_example_dir('zipped_imports', 'not_pkg.zip')