Make object attribute access act like dictionary access, raising an

error for any property (including custom or optional) not set on the object.

stix2/base.py

@@ -73,7 +73,8 @@ class _STIXBase(collections.Mapping):
         failed_dependency_pairs = []
         for p in list_of_properties:
             for dp in list_of_dependent_properties:
-                if not self.__getattr__(p) and self.__getattr__(dp):
+                if ((not hasattr(self, p) or (hasattr(self, p) and not self.__getattr__(p))) and
+                        hasattr(self, dp) and self.__getattr__(dp)):
                     failed_dependency_pairs.append((p, dp))
         if failed_dependency_pairs:
             raise DependentPropertiesError(self.__class__, failed_dependency_pairs)
@@ -128,10 +129,6 @@ class _STIXBase(collections.Mapping):
             # Return attribute value.
             return self.__getitem__(name)
         except KeyError:
-            # If attribute not found, check if its a property of the object.
-            if name in self._properties:
-                return None
-
             raise AttributeError("'%s' object has no attribute '%s'" %
                                  (self.__class__.__name__, name))
 
@@ -163,7 +160,7 @@ class _STIXBase(collections.Mapping):
 
     def new_version(self, **kwargs):
         unchangable_properties = []
-        if self.revoked:
+        if hasattr(self, 'revoked') and self.revoked:
             raise RevokeError("new_version")
         new_obj_inner = copy.deepcopy(self._inner)
         properties_to_change = kwargs.keys()
@@ -183,7 +180,7 @@ class _STIXBase(collections.Mapping):
         return cls(**new_obj_inner)
 
     def revoke(self):
-        if self.revoked:
+        if hasattr(self, 'revoked') and self.revoked:
             raise RevokeError("revoke")
         return self.new_version(revoked=True)
 

stix2/observables.py

@@ -443,10 +443,10 @@ class Process(_Observable):
         super(Process, self)._check_object_constraints()
         try:
             self._check_at_least_one_property()
-            if self.extensions and "windows-process-ext" in self.extensions:
+            if hasattr(self, 'extensions') and "windows-process-ext" in self.extensions:
                 self.extensions["windows-process-ext"]._check_at_least_one_property()
         except AtLeastOnePropertyError as enclosing_exc:
-            if not self.extensions:
+            if not hasattr(self, 'extensions'):
                 raise enclosing_exc
             else:
                 if "windows-process-ext" in self.extensions:

stix2/properties.py

@@ -244,6 +244,8 @@ class ObservableProperty(Property):
             dictified = get_dict(value)
         except ValueError:
             raise ValueError("The observable property must contain a dictionary")
+        if dictified == {}:
+            raise ValueError("The dictionary property must contain a non-empty dictionary")
 
         valid_refs = dict((k, v['type']) for (k, v) in dictified.items())
 
@@ -265,6 +267,8 @@ class DictionaryProperty(Property):
             dictified = get_dict(value)
         except ValueError:
             raise ValueError("The dictionary property must contain a dictionary")
+        if dictified == {}:
+            raise ValueError("The dictionary property must contain a non-empty dictionary")
 
         for k in dictified.keys():
             if len(k) < 3:
@@ -418,6 +422,8 @@ class ExtensionsProperty(DictionaryProperty):
             dictified = get_dict(value)
         except ValueError:
             raise ValueError("The extensions property must contain a dictionary")
+        if dictified == {}:
+            raise ValueError("The dictionary property must contain a non-empty dictionary")
 
         from .__init__ import EXT_MAP  # avoid circular import
         if self.enclosing_type in EXT_MAP:

stix2/test/test_bundle.py

@@ -48,7 +48,8 @@ def test_empty_bundle():
     assert bundle.type == "bundle"
     assert bundle.id.startswith("bundle--")
     assert bundle.spec_version == "2.0"
-    assert bundle.objects is None
+    with pytest.raises(AttributeError):
+        assert bundle.objects
 
 
 def test_bundle_with_wrong_type():

stix2/test/test_observed_data.py

@@ -199,6 +199,13 @@ def test_parse_artifact_invalid(data):
         stix2.parse(odata_str)
 
 
+def test_artifact_example_dependency_error():
+    with pytest.raises(stix2.exceptions.DependentPropertiesError) as excinfo:
+        stix2.Artifact(url="http://example.com/sirvizio.exe")
+
+    assert excinfo.value.dependencies == [("hashes", "url")]
+
+
 @pytest.mark.parametrize("data", [
     """"0": {
         "type": "autonomous-system",
@@ -769,6 +776,10 @@ def test_file_example_encryption_error():
     assert excinfo.value.cls == stix2.File
     assert excinfo.value.dependencies == [("is_encrypted", "encryption_algorithm")]
 
+    with pytest.raises(stix2.exceptions.DependentPropertiesError) as excinfo:
+        stix2.File(name="qwerty.dll",
+                   encryption_algorithm="AES128-CBC")
+
 
 def test_ip4_address_example():
     ip4 = stix2.IPv4Address(_valid_refs={"4": "mac-addr", "5": "mac-addr"},
@@ -916,14 +927,12 @@ def test_process_example_windows_process_ext_empty():
 
 
 def test_process_example_extensions_empty():
-    with pytest.raises(stix2.exceptions.AtLeastOnePropertyError) as excinfo:
+    with pytest.raises(stix2.exceptions.InvalidValueError) as excinfo:
-            stix2.Process(extensions={
+            stix2.Process(extensions={})
-                          })
 
     assert excinfo.value.cls == stix2.Process
-    properties_of_process = list(stix2.Process._properties.keys())
+    assert excinfo.value.prop_name == 'extensions'
-    properties_of_process.remove("type")
+    assert 'non-empty dictionary' in excinfo.value.reason
-    assert excinfo.value.properties == sorted(properties_of_process)
 
 
 def test_process_example_with_WindowsProcessExt_Object():

stix2/test/test_versioning.py

@@ -40,7 +40,8 @@ def test_making_new_version_with_unset():
     assert campaign_v1.created_by_ref == campaign_v2.created_by_ref
     assert campaign_v1.created == campaign_v2.created
     assert campaign_v1.name == campaign_v2.name
-    assert campaign_v2.description is None
+    with pytest.raises(AttributeError):
+        assert campaign_v2.description
     assert campaign_v1.modified < campaign_v2.modified