Add parse() to Environment layer

The Environment layer does not keep its own mapping of custom object types.
If we think it likely that users will want to maintain separate lists of
custom object types between two or more Environments, we can add this
later.

stix2/core.py

@@ -75,13 +75,13 @@ def parse(data, allow_custom=False):
     """Deserialize a string or file-like object into a STIX object.
 
     Args:
-        data: The STIX 2 string to be parsed.
+        data (str, dict, file-like object): The STIX 2 content to be parsed.
         allow_custom (bool): Whether to allow custom properties or not. Default: False.
 
     Returns:
         An instantiated Python STIX object.
-    """
 
+    """
     obj = get_dict(data)
 
     if 'type' not in obj:
@@ -96,6 +96,6 @@ def parse(data, allow_custom=False):
 
 def _register_type(new_type):
     """Register a custom STIX Object type.
-    """
 
+    """
     OBJ_MAP[new_type._type] = new_type

stix2/environment.py

@@ -1,5 +1,6 @@
 import copy
 
+from .core import parse as _parse
 from .sources import CompositeDataSource, DataSource, DataStore
 
 
@@ -149,3 +150,7 @@ class Environment(object):
         except AttributeError:
             raise AttributeError('Environment has no data sink to put objects in')
     add.__doc__ = DataStore.add.__doc__
+
+    def parse(self, *args, **kwargs):
+        return _parse(*args, **kwargs)
+    parse.__doc__ = _parse.__doc__

stix2/test/test_environment.py

@@ -3,7 +3,7 @@ import pytest
 import stix2
 
 from .constants import (FAKE_TIME, IDENTITY_ID, IDENTITY_KWARGS, INDICATOR_ID,
-                        INDICATOR_KWARGS)
+                        INDICATOR_KWARGS, MALWARE_ID)
 
 
 def test_object_factory_created_by_ref_str():
@@ -164,3 +164,25 @@ def test_environment_datastore_and_no_object_factory():
     env = stix2.Environment(store=stix2.MemoryStore())
     ind = env.create(stix2.Indicator, id=INDICATOR_ID, **INDICATOR_KWARGS)
     assert ind.id == INDICATOR_ID
+
+
+def test_parse_malware():
+    env = stix2.Environment()
+    data = """{
+        "type": "malware",
+        "id": "malware--fedcba98-7654-3210-fedc-ba9876543210",
+        "created": "2017-01-01T12:34:56.000Z",
+        "modified": "2017-01-01T12:34:56.000Z",
+        "name": "Cryptolocker",
+        "labels": [
+            "ransomware"
+        ]
+    }"""
+    mal = env.parse(data)
+
+    assert mal.type == 'malware'
+    assert mal.id == MALWARE_ID
+    assert mal.created == FAKE_TIME
+    assert mal.modified == FAKE_TIME
+    assert mal.labels == ['ransomware']
+    assert mal.name == "Cryptolocker"