Add type annotations; use Value type in RD annotations

Signed-off-by: Marcela Melara <marcela.melara@intel.com>

python/in_toto_attestation/v1/resource_descriptor.py

@@ -1,28 +1,37 @@
 #  Wrapper class for in-toto attestation ResourceDescriptor protos.
 
 import in_toto_attestation.v1.resource_descriptor_pb2 as rdpb
+from google.protobuf.struct_pb2 import Value
+import google.protobuf.json_format as pb_json
+import json
 
 class ResourceDescriptor:
-    def __init__(self, name='', uri='', digest={}, content=bytes(), download_location='', media_type='', annotations={}):
+    def __init__(self, name='', uri='', digest=None, content=bytes(), download_location='', media_type='', annotations=None) -> None:
         self.pb = rdpb.ResourceDescriptor()
         self.pb.name = name
         self.pb.uri = uri
-        self.pb.digest.update(digest)
+        if digest:
+            self.pb.digest.update(digest)
         self.pb.content = content
         self.pb.downloadLocation = download_location
         self.pb.mediaType = media_type
 
         # HACK
-        for k,v in annotations.items():
-            self.pb.annotations[k].update(v)
+        if annotations:
+            # Value type fields are considered Messages in Python.
+            # this is needed to set Value fields into the annotations map
+            # without having to know its value type a priori.
+            for k, v in annotations.items():
+                val_pb = pb_json.Parse(json.dumps(v), Value())
+                self.pb.annotations[k].CopyFrom(val_pb)
 
     @staticmethod
-    def copy_from_pb(proto):
+    def copy_from_pb(proto: type[rdpb.ResourceDescriptor]) -> 'ResourceDescriptor':
         rd = ResourceDescriptor()
         rd.pb.CopyFrom(proto)
         return rd
 
-    def validate(self):
+    def validate(self) -> None:
         # at least one of name, URI or digest are required
         if self.pb.name == '' and self.pb.uri == '' and len(self.pb.digest) == 0:
             raise ValueError("At least one of name, URI, or digest need to be set")

python/in_toto_attestation/v1/statement.py

@@ -6,20 +6,20 @@
 STATEMENT_TYPE_URI = 'https://in-toto.io/Statement/v1'
 
 class Statement:
-    def __init__(self, subjects=[], predicate_type='', predicate={}):
+    def __init__(self, subjects: list, predicate_type: str, predicate: dict) -> None:
         self.pb = spb.Statement()
         self.pb.type = STATEMENT_TYPE_URI
         self.pb.subject.extend(subjects)
         self.pb.predicateType = predicate_type
         self.pb.predicate.update(predicate)
 
     @staticmethod
-    def copy_from_pb(proto):
-        stmt = Statement()
+    def copy_from_pb(proto: type[spb.Statement]) -> 'Statement':
+        stmt = Statement([], '', {})
         stmt.pb.CopyFrom(proto)
         return stmt
 
-    def validate(self):    
+    def validate(self) -> None:    
         if self.pb.type != STATEMENT_TYPE_URI:
             raise ValueError('Wrong statement type')
 

tests/python/test_resource_descriptor.py

@@ -9,7 +9,7 @@
 from in_toto_attestation.v1.resource_descriptor import ResourceDescriptor
 
 def create_test_desc():
-    desc = ResourceDescriptor('theName', 'https://example.com', {'alg':'abc123'}, b'bytescontent', 'https://example.com/test.zip', 'theMediaType', {'a1':{'keyStr': 'val1', 'keyNum': 13}, 'a2': {'keyObj': {'subKey': 'subVal'}}})
+    desc = ResourceDescriptor('theName', 'https://example.com', {'alg':'abc123'}, b'bytescontent', 'https://example.com/test.zip', 'theMediaType', {'keyStr': 'val1', 'keyNum': 13, 'keyObj': {'subKey': 'subVal'}})
 
     return desc
 
@@ -19,7 +19,7 @@ def test_create_resource_descriptor(self):
         test_rd.validate()
 
     def test_json_parse_resource_descriptor(self):
-        full_rd = '{"name":"theName","uri":"https://example.com","digest":{"alg":"abc123"},"content":"Ynl0ZXNjb250ZW50","downloadLocation":"https://example.com/test.zip","mediaType":"theMediaType","annotations":{"a1":{"keyNum": 13,"keyStr":"val1"},"a2":{"keyObj":{"subKey":"subVal"}}}}'
+        full_rd = '{"name":"theName","uri":"https://example.com","digest":{"alg":"abc123"},"content":"Ynl0ZXNjb250ZW50","downloadLocation":"https://example.com/test.zip","mediaType":"theMediaType","annotations":{"keyNum": 13,"keyStr":"val1","keyObj":{"subKey":"subVal"}}}'
         got_pb = pb_json.Parse(full_rd, rdpb.ResourceDescriptor())
         got = got_pb.SerializeToString(deterministic=True)