Merge #446

446: vfs: Handle if __main__ has no __file__ r=pathunstrom a=astronouth7303

Closes #267
Closes #437

Co-authored-by: Jamie Bliss <jamie@ivyleav.es>
Co-authored-by: Piper Thunstrom <pathunstrom@gmail.com>

ppb/vfs.py

@@ -19,7 +19,7 @@
 
 def _main_path():
     main = sys.modules['__main__']
-    mainpath = getattr(main, '__file__')
+    mainpath = getattr(main, '__file__', None)
     if mainpath:
         mainpath = Path(mainpath)
         return mainpath.absolute().parent

tests/test_vfs.py

@@ -0,0 +1,49 @@
+import contextlib
+import os
+import tempfile
+
+import __main__  # The pytest entry point
+
+import pytest
+
+import ppb.vfs
+
+
+@contextlib.contextmanager
+def save_main_file():
+    value = __main__.__file__
+    try:
+        yield
+    finally:
+        __main__.__file__ = value
+
+
+@pytest.fixture
+def cwd_file():
+    # Windows doesn't like multiple open handles, so we need to close and
+    # delete the temp file manually.
+
+    with tempfile.NamedTemporaryFile(dir=os.getcwd(), delete=False) as ntf:
+        ntf.close()
+        yield os.path.basename(ntf.name)
+        os.remove(ntf.name)
+
+
+def test_main_normal(cwd_file):
+    with pytest.raises(FileNotFoundError):
+        with ppb.vfs.open(cwd_file):
+            pass
+
+
+def test_main_none(cwd_file):
+    with save_main_file():
+        __main__.__file__ = None
+        with ppb.vfs.open(cwd_file):
+            pass
+
+
+def test_main_missing(cwd_file):
+    with save_main_file():
+        del __main__.__file__
+        with ppb.vfs.open(cwd_file):
+            pass