Added tests for load_session() and dump_session()

tests/test_session.py

@@ -0,0 +1,130 @@
+#!/usr/bin/env python
+
+# Author: Leonardo Gama (@leogama)
+# Copyright (c) 2008-2016 California Institute of Technology.
+# Copyright (c) 2016-2022 The Uncertainty Quantification Foundation.
+# License: 3-clause BSD.  The full license text is available at:
+#  - https://github.com/uqfoundation/dill/blob/master/LICENSE
+
+from __future__ import print_function
+import dill, sys, __main__
+from dill._dill import StringIO, PY3
+
+original_modules = set(sys.modules.keys())
+original_objects = set(__main__.__dict__.keys())
+original_objects.add('original_objects')
+original_objects.remove('__main__')
+del __main__
+
+
+# Make sure modules imported for testing are not already imported by dill.
+if any(mod in sys.modules for mod in ('json', 'urllib', 'xml', 'calendar', 'cmath')):
+    raise Warning("Some test module was imported before the beginning of the tests.")
+
+
+# Create various kinds of objects to test different internal logics.
+
+## Modules.
+import json                             # top-level module
+import urllib as url                    # top-level module under alias
+from xml import sax                     # submodule
+import xml.dom.minidom as dom           # submodule under alias
+
+## Imported objects.
+from calendar import Calendar, isleap, day_name     # class, function, other object
+from cmath import log as complex_log                # imported with alias
+
+## Local objects.
+x = 17
+empty = None
+names = ['Alice', 'Bob', 'Carol']
+def squared(x): return x**2
+cubed = lambda x: x**3
+class Person:
+    def __init__(self, name, age):
+        self.name = name
+        self.age = age
+person = Person(names[0], x)
+class CalendarSubclass(Calendar):
+    def weekdays(self):
+        return [day_name[i] for i in self.iterweekdays()]
+cal = CalendarSubclass()
+
+
+def test_objects(main, copy_dict, byref):
+    main_dict = main.__dict__
+
+    try:
+        for obj in ('json', 'url', 'sax', 'dom'):
+            assert main_dict[obj].__name__ == copy_dict[obj].__name__
+            assert main_dict[obj].__name__ in sys.modules
+
+        #FIXME: In the second test call, 'calendar' is not included in
+        # sys.modules, independent of the value of byref. Tried to run garbage
+        # collection before with no luck. This block fails even with
+        # "import calendar" before it. Needed to restore the original modules
+        # with the 'copy_modules' object.
+        for obj in ('Calendar', 'isleap'):
+            assert main_dict[obj] is sys.modules['calendar'].__dict__[obj]
+        assert main_dict['day_name'].__module__ == 'calendar'
+        if byref:
+            assert main_dict['day_name'] is sys.modules['calendar'].__dict__['day_name']
+
+        assert complex_log is sys.modules['cmath'].__dict__['log']
+
+        for obj in ('x', 'empty', 'names'):
+            assert main_dict[obj] == copy_dict[obj]
+
+        globs = '__globals__' if PY3 else 'func_globals'
+        for obj in ['squared', 'cubed']:
+            assert getattr(main_dict[obj], globs) is main_dict
+            assert main_dict[obj](3) == copy_dict[obj](3)
+
+        assert main_dict['Person'].__module__ == main.__name__
+        assert isinstance(main_dict['person'], main_dict['Person'])
+        assert main_dict['person'].age == copy_dict['person'].age
+
+        assert issubclass(main_dict['CalendarSubclass'], main_dict['Calendar'])
+        assert isinstance(main_dict['cal'], main_dict['CalendarSubclass'])
+        assert main_dict['cal'].weekdays() == copy_dict['cal'].weekdays()
+
+    except AssertionError:
+        import traceback
+        error_line = traceback.format_exc().splitlines()[-2].replace('[obj]', '['+repr(obj)+']')
+        print("Error while testing (byref=%s):" % byref, error_line, sep="\n", file=sys.stderr)
+        raise
+
+
+if __name__ == '__main__':
+    # Test dump_session() and load_session().
+    for byref in (False, True):
+        #print(sorted(set(sys.modules.keys()) - original_modules))
+        dill._test_file = StringIO()
+        try:
+            dill.dump_session(dill._test_file, byref=byref)
+            dump = dill._test_file.getvalue()
+            dill._test_file.close()
+
+            import __main__
+            copy_dict = __main__.__dict__.copy()
+            copy_modules = sys.modules.copy()
+            del copy_dict['dump']
+            del copy_dict['__main__']
+            for name in copy_dict.keys():
+                if name not in original_objects:
+                    del __main__.__dict__[name]
+            for module in list(sys.modules.keys()):
+                if module not in original_modules:
+                    del sys.modules[module]
+
+            dill._test_file = StringIO(dump)
+            dill.load_session(dill._test_file)
+            #print(sorted(set(sys.modules.keys()) - original_modules))
+        finally:
+            dill._test_file.close()
+            del dill._test_file
+
+        test_objects(__main__, copy_dict, byref)
+        __main__.__dict__.update(copy_dict)
+        sys.modules.update(copy_modules)
+        del __main__, copy_dict, copy_modules, dump