Add exception for invalid Property values.

stix2/__init__.py

@@ -9,3 +9,5 @@ from .sdo import AttackPattern, Campaign, CourseOfAction, Identity, Indicator, \
     Vulnerability
 from .sro import Relationship, Sighting
 from .markings import MarkingDefinition, GranularMarking, StatementMarking, TLPMarking
+
+from . import exceptions

stix2/base.py

@@ -4,6 +4,7 @@ import collections
 import datetime as dt
 import json
 
+from .exceptions import STIXValueError
 from .utils import format_datetime, get_timestamp, NOW
 
 __all__ = ['STIXJSONEncoder', '_STIXBase']
@@ -41,10 +42,7 @@ class _STIXBase(collections.Mapping):
             try:
                 kwargs[prop_name] = prop.validate(kwargs[prop_name])
             except ValueError as exc:
-                msg = "Invalid value for {0} '{1}': {2}"
-                raise ValueError(msg.format(self.__class__.__name__,
-                                            prop_name,
-                                            exc))
+                raise STIXValueError(self.__class__, prop_name, reason=str(exc))
 
     def __init__(self, **kwargs):
         cls = self.__class__

stix2/exceptions.py

@@ -0,0 +1,15 @@
+class STIXError(Exception):
+    """Base class for errors generated in the stix2 library."""
+
+
+class STIXValueError(STIXError, ValueError):
+    """An invalid value was provided to a STIX object's __init__."""
+
+    def __init__(self, cls, prop_name, reason):
+        self.cls = cls
+        self.prop_name = prop_name
+        self.reason = reason
+
+    def __str__(self):
+        msg = "Invalid value for {0.cls.__name__} '{0.prop_name}': {0.reason}"
+        return msg.format(self)

stix2/properties.py

@@ -158,5 +158,5 @@ class SelectorProperty(Property):
 
     def validate(self, value):
         if not SELECTOR_REGEX.match(value):
-            raise ValueError("values must adhere to selector syntax")
+            raise ValueError("must adhere to selector syntax.")
         return value

stix2/test/test_bundle.py

@@ -51,23 +51,32 @@ def test_empty_bundle():
 
 
 def test_bundle_with_wrong_type():
-    with pytest.raises(ValueError) as excinfo:
+    with pytest.raises(stix2.exceptions.STIXValueError) as excinfo:
         stix2.Bundle(type="not-a-bundle")
 
+    assert excinfo.value.cls == stix2.Bundle
+    assert excinfo.value.prop_name == "type"
+    assert excinfo.value.reason == "must equal 'bundle'."
     assert str(excinfo.value) == "Invalid value for Bundle 'type': must equal 'bundle'."
 
 
 def test_bundle_id_must_start_with_bundle():
-    with pytest.raises(ValueError) as excinfo:
+    with pytest.raises(stix2.exceptions.STIXValueError) as excinfo:
         stix2.Bundle(id='my-prefix--')
 
+    assert excinfo.value.cls == stix2.Bundle
+    assert excinfo.value.prop_name == "id"
+    assert excinfo.value.reason == "must start with 'bundle--'."
     assert str(excinfo.value) == "Invalid value for Bundle 'id': must start with 'bundle--'."
 
 
 def test_bundle_with_wrong_spec_version():
-    with pytest.raises(ValueError) as excinfo:
+    with pytest.raises(stix2.exceptions.STIXValueError) as excinfo:
         stix2.Bundle(spec_version="1.2")
 
+    assert excinfo.value.cls == stix2.Bundle
+    assert excinfo.value.prop_name == "spec_version"
+    assert excinfo.value.reason == "must equal '2.0'."
     assert str(excinfo.value) == "Invalid value for Bundle 'spec_version': must equal '2.0'."
 
 

stix2/test/test_indicator.py

@@ -67,16 +67,22 @@ def test_indicator_autogenerated_fields(indicator):
 
 
 def test_indicator_type_must_be_indicator():
-    with pytest.raises(ValueError) as excinfo:
+    with pytest.raises(stix2.exceptions.STIXValueError) as excinfo:
         stix2.Indicator(type='xxx', **INDICATOR_KWARGS)
 
+    assert excinfo.value.cls == stix2.Indicator
+    assert excinfo.value.prop_name == "type"
+    assert excinfo.value.reason == "must equal 'indicator'."
     assert str(excinfo.value) == "Invalid value for Indicator 'type': must equal 'indicator'."
 
 
 def test_indicator_id_must_start_with_indicator():
-    with pytest.raises(ValueError) as excinfo:
+    with pytest.raises(stix2.exceptions.STIXValueError) as excinfo:
         stix2.Indicator(id='my-prefix--', **INDICATOR_KWARGS)
 
+    assert excinfo.value.cls == stix2.Indicator
+    assert excinfo.value.prop_name == "id"
+    assert excinfo.value.reason == "must start with 'indicator--'."
     assert str(excinfo.value) == "Invalid value for Indicator 'id': must start with 'indicator--'."
 
 
@@ -93,14 +99,22 @@ def test_indicator_required_field_pattern():
 
 
 def test_indicator_created_ref_invalid_format():
-    with pytest.raises(ValueError) as excinfo:
+    with pytest.raises(stix2.exceptions.STIXValueError) as excinfo:
         stix2.Indicator(created_by_ref='myprefix--12345678', **INDICATOR_KWARGS)
+
+    assert excinfo.value.cls == stix2.Indicator
+    assert excinfo.value.prop_name == "created_by_ref"
+    assert excinfo.value.reason == "must start with 'identity'."
     assert str(excinfo.value) == "Invalid value for Indicator 'created_by_ref': must start with 'identity'."
 
 
 def test_indicator_revoked_invalid():
-    with pytest.raises(ValueError) as excinfo:
+    with pytest.raises(stix2.exceptions.STIXValueError) as excinfo:
         stix2.Indicator(revoked='false', **INDICATOR_KWARGS)
+
+    assert excinfo.value.cls == stix2.Indicator
+    assert excinfo.value.prop_name == "revoked"
+    assert excinfo.value.reason == "must be a boolean value."
     assert str(excinfo.value) == "Invalid value for Indicator 'revoked': must be a boolean value."
 
 

stix2/test/test_malware.py

@@ -51,16 +51,22 @@ def test_malware_autogenerated_fields(malware):
 
 
 def test_malware_type_must_be_malware():
-    with pytest.raises(ValueError) as excinfo:
+    with pytest.raises(stix2.exceptions.STIXValueError) as excinfo:
         stix2.Malware(type='xxx', **MALWARE_KWARGS)
 
+    assert excinfo.value.cls == stix2.Malware
+    assert excinfo.value.prop_name == "type"
+    assert excinfo.value.reason == "must equal 'malware'."
     assert str(excinfo.value) == "Invalid value for Malware 'type': must equal 'malware'."
 
 
 def test_malware_id_must_start_with_malware():
-    with pytest.raises(ValueError) as excinfo:
+    with pytest.raises(stix2.exceptions.STIXValueError) as excinfo:
         stix2.Malware(id='my-prefix--', **MALWARE_KWARGS)
 
+    assert excinfo.value.cls == stix2.Malware
+    assert excinfo.value.prop_name == "id"
+    assert excinfo.value.reason == "must start with 'malware--'."
     assert str(excinfo.value) == "Invalid value for Malware 'id': must start with 'malware--'."
 
 

stix2/test/test_markings.py

@@ -87,13 +87,16 @@ def test_granular_example():
 
 
 def test_granular_example_with_bad_selector():
-    with pytest.raises(ValueError) as excinfo:
+    with pytest.raises(stix2.exceptions.STIXValueError) as excinfo:
         stix2.GranularMarking(
             marking_ref="marking-definition--613f2e26-407d-48c7-9eca-b8e91df99dc9",
             selectors=["abc[0]"]   # missing "."
         )
 
-    assert str(excinfo.value) == "Invalid value for GranularMarking 'selectors': values must adhere to selector syntax"
+    assert excinfo.value.cls == stix2.GranularMarking
+    assert excinfo.value.prop_name == "selectors"
+    assert excinfo.value.reason == "must adhere to selector syntax."
+    assert str(excinfo.value) == "Invalid value for GranularMarking 'selectors': must adhere to selector syntax."
 
 
 def test_campaign_with_granular_markings_example():

stix2/test/test_relationship.py

@@ -54,16 +54,22 @@ def test_relationship_autogenerated_fields(relationship):
 
 
 def test_relationship_type_must_be_relationship():
-    with pytest.raises(ValueError) as excinfo:
+    with pytest.raises(stix2.exceptions.STIXValueError) as excinfo:
         stix2.Relationship(type='xxx', **RELATIONSHIP_KWARGS)
 
+    assert excinfo.value.cls == stix2.Relationship
+    assert excinfo.value.prop_name == "type"
+    assert excinfo.value.reason == "must equal 'relationship'."
     assert str(excinfo.value) == "Invalid value for Relationship 'type': must equal 'relationship'."
 
 
 def test_relationship_id_must_start_with_relationship():
-    with pytest.raises(ValueError) as excinfo:
+    with pytest.raises(stix2.exceptions.STIXValueError) as excinfo:
         stix2.Relationship(id='my-prefix--', **RELATIONSHIP_KWARGS)
 
+    assert excinfo.value.cls == stix2.Relationship
+    assert excinfo.value.prop_name == "id"
+    assert excinfo.value.reason == "must start with 'relationship--'."
     assert str(excinfo.value) == "Invalid value for Relationship 'id': must start with 'relationship--'."
 
 

stix2/test/test_report.py

@@ -63,7 +63,7 @@ def test_report_example_objects_in_object_refs():
 
 
 def test_report_example_objects_in_object_refs_with_bad_id():
-    with pytest.raises(ValueError) as excinfo:
+    with pytest.raises(stix2.exceptions.STIXValueError) as excinfo:
         stix2.Report(
             id="report--84e4d88f-44ea-4bcd-bbf3-b2c1c320bcb3",
             created_by_ref="identity--a463ffb3-1bd9-4d94-b02d-74e4f1658283",
@@ -80,6 +80,9 @@ def test_report_example_objects_in_object_refs_with_bad_id():
             ],
         )
 
+    assert excinfo.value.cls == stix2.Report
+    assert excinfo.value.prop_name == "object_refs"
+    assert excinfo.value.reason == "must match <object-type>--<guid>."
     assert str(excinfo.value) == "Invalid value for Report 'object_refs': must match <object-type>--<guid>."
 
 # TODO: Add other examples

stix2/test/test_sighting.py

@@ -48,7 +48,7 @@ def test_sighting_all_required_fields():
 def test_sighting_bad_where_sighted_refs():
     now = dt.datetime(2016, 4, 6, 20, 6, 37, tzinfo=pytz.utc)
 
-    with pytest.raises(ValueError) as excinfo:
+    with pytest.raises(stix2.exceptions.STIXValueError) as excinfo:
         stix2.Sighting(
             type='sighting',
             id=SIGHTING_ID,
@@ -58,13 +58,19 @@ def test_sighting_bad_where_sighted_refs():
             where_sighted_refs=["malware--8cc7afd6-5455-4d2b-a736-e614ee631d99"]
         )
 
+    assert excinfo.value.cls == stix2.Sighting
+    assert excinfo.value.prop_name == "where_sighted_refs"
+    assert excinfo.value.reason == "must start with 'identity'."
     assert str(excinfo.value) == "Invalid value for Sighting 'where_sighted_refs': must start with 'identity'."
 
 
 def test_sighting_type_must_be_sightings():
-    with pytest.raises(ValueError) as excinfo:
+    with pytest.raises(stix2.exceptions.STIXValueError) as excinfo:
         stix2.Sighting(type='xxx', **SIGHTING_KWARGS)
 
+    assert excinfo.value.cls == stix2.Sighting
+    assert excinfo.value.prop_name == "type"
+    assert excinfo.value.reason == "must equal 'sighting'."
     assert str(excinfo.value) == "Invalid value for Sighting 'type': must equal 'sighting'."