added versioning test for embedded_object

replaced VersioningError with RevokeError and UnmodifiablePropertyError
added __deepcopy__ to base class to handle embedded_objects

stix2/base.py

@@ -7,7 +7,7 @@ import json
 
 
 from .exceptions import ExtraFieldsError, ImmutableError, InvalidValueError, \
-                        MissingFieldsError, VersioningError
+                        MissingFieldsError, RevokeError, UnmodifiablePropertyError
 from .utils import format_datetime, get_timestamp, NOW
 
 __all__ = ['STIXJSONEncoder', '_STIXBase']
@@ -102,32 +102,32 @@ class _STIXBase(collections.Mapping):
         return "{0}({1})".format(self.__class__.__name__,
                                  ", ".join(["{0!s}={1!r}".format(k, v) for k, v in props]))
 
+    def __deepcopy__(self, memo):
+        # Assumption: we can ignore the memo argument, because no object will ever contain the same sub-object multiple times.
+        new_inner = copy.deepcopy(self._inner, memo)
+        cls = type(self)
+        return cls(**new_inner)
+
 #  Versioning API
 
     def new_version(self, **kwargs):
         unchangable_properties = []
         if self.revoked:
-            raise VersioningError("Cannot create a new version of a revoked object")
+            raise RevokeError("new_version")
         new_obj_inner = copy.deepcopy(self._inner)
         properties_to_change = kwargs.keys()
-        if "type" in properties_to_change:
-            unchangable_properties.append("type")
-        if "id" in properties_to_change:
-            unchangable_properties.append("id")
-        if "created" in properties_to_change:
-            unchangable_properties.append("created")
-        if "created_by_ref" in properties_to_change:
-            unchangable_properties.append("created_by_ref")
+        for prop in ["created", "created_by_ref", "id", "type"]:
+            if prop in properties_to_change:
+                unchangable_properties.append(prop)
         if unchangable_properties:
-            raise VersioningError("These properties cannot be changed when making a new version: " + ", ".join(unchangable_properties))
+            raise UnmodifiablePropertyError(unchangable_properties)
         if 'modified' not in kwargs:
             kwargs['modified'] = get_timestamp()
         new_obj_inner.update(kwargs)
-
         cls = type(self)
         return cls(**new_obj_inner)
 
     def revoke(self):
         if self.revoked:
-            raise VersioningError("Cannot revoke an already revoked object")
+            raise RevokeError("revoke")
         return self.new_version(revoked=True)

stix2/exceptions.py

@@ -51,8 +51,27 @@ class ImmutableError(STIXError, ValueError):
         super(ImmutableError, self).__init__("Cannot modify properties after creation.")
 
 
-class VersioningError(STIXError, ValueError):
-    """Execption while using the Versioning API"""
+class UnmodifiablePropertyError(STIXError, ValueError):
+    """Attempted to modify an unmodifiable property of object when creating a new version"""
 
-    def __init__(self, msg):
-        super(VersioningError, self).__init__(msg)
+    def __init__(self, unchangable_properties):
+        super(UnmodifiablePropertyError, self).__init__()
+        self.unchangable_properties = unchangable_properties
+
+    def __str__(self):
+        msg = "These properties cannot be changed when making a new version: {0}."
+        return msg.format(", ".join(self.unchangable_properties))
+
+
+class RevokeError(STIXError, ValueError):
+    """Attempted to an operation on a revoked object"""
+
+    def __init__(self, called_by):
+        super(RevokeError, self).__init__()
+        self.called_by = called_by
+
+    def __str__(self):
+        if self.called_by == "revoke":
+            return "Cannot revoke an already revoked object."
+        else:
+            return "Cannot create a new version of a revoked object."

stix2/test/test_versioning.py

@@ -23,6 +23,34 @@ def test_making_new_version():
     assert campaign_v1.modified < campaign_v2.modified
 
 
+def test_making_new_version_with_embedded_object():
+    campaign_v1 = stix2.Campaign(
+        id="campaign--8e2e2d2b-17d4-4cbf-938f-98ee46b3cd3f",
+        created_by_ref="identity--f431f809-377b-45e0-aa1c-6a4751cae5ff",
+        created="2016-04-06T20:03:00.000Z",
+        modified="2016-04-06T20:03:00.000Z",
+        name="Green Group Attacks Against Finance",
+        external_references=[{
+            "source_name": "capec",
+            "external_id": "CAPEC-163"
+        }],
+        description="Campaign by Green Group against a series of targets in the financial services sector."
+    )
+
+    campaign_v2 = campaign_v1.new_version(external_references=[{
+            "source_name": "capec",
+            "external_id": "CAPEC-164"
+        }])
+
+    assert campaign_v1.id == campaign_v2.id
+    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_v1.description == campaign_v2.description
+    assert campaign_v1.modified < campaign_v2.modified
+    assert campaign_v1.external_references[0].external_id != campaign_v2.external_references[0].external_id
+
+
 def test_revoke():
     campaign_v1 = stix2.Campaign(
         id="campaign--8e2e2d2b-17d4-4cbf-938f-98ee46b3cd3f",
@@ -55,7 +83,7 @@ def test_versioning_error_invalid_property():
         description="Campaign by Green Group against a series of targets in the financial services sector."
     )
 
-    with pytest.raises(stix2.exceptions.VersioningError) as excinfo:
+    with pytest.raises(stix2.exceptions.UnmodifiablePropertyError) as excinfo:
         campaign_v1.new_version(type="threat-actor")
 
     str(excinfo.value) == "These properties cannot be changed when making a new version: type"
@@ -73,7 +101,7 @@ def test_versioning_error_new_version_of_revoked():
 
     campaign_v2 = campaign_v1.revoke()
 
-    with pytest.raises(stix2.exceptions.VersioningError) as excinfo:
+    with pytest.raises(stix2.exceptions.RevokeError) as excinfo:
         campaign_v2.new_version(name="barney")
 
     str(excinfo.value) == "Cannot create a new version of a revoked object"
@@ -91,7 +119,7 @@ def test_versioning_error_revoke_of_revoked():
 
     campaign_v2 = campaign_v1.revoke()
 
-    with pytest.raises(stix2.exceptions.VersioningError) as excinfo:
+    with pytest.raises(stix2.exceptions.RevokeError) as excinfo:
         campaign_v2.revoke()
 
     str(excinfo.value) == "Cannot revoke an already revoked object"