Added WrapperKeepOpaque type

scalecodec/type_registry/metadata_types.json

@@ -1570,6 +1570,7 @@
     "pallet_identity::types::Data": "Data",
     "frame_support::storage::bounded_vec::BoundedVec": "BoundedVec",
     "frame_support::storage::weak_bounded_vec::WeakBoundedVec": "BoundedVec",
+    "frame_support::traits::misc::WrapperKeepOpaque": "WrapperKeepOpaque",
     "*::Call": "GenericCall",
     "*::Event": {
       "type": "struct",

scalecodec/types.py

@@ -1529,6 +1529,44 @@ def process(self):
             return value
 
 
+class WrapperKeepOpaque(Struct):
+
+    def process_encode(self, value):
+        # Check requirements
+        if not self.type_mapping or len(self.type_mapping) != 2:
+            raise ValueError("type_mapping not set correctly for this WrapperKeepOpaque")
+
+        wrapped_obj = self.runtime_config.create_scale_object(
+            type_string=self.type_mapping[1], metadata=self.metadata
+        )
+
+        wrapped_obj.encode(value)
+
+        bytes_obj = self.runtime_config.create_scale_object("Bytes")
+        return bytes_obj.encode(wrapped_obj.get_used_bytes())
+
+    def process(self):
+        # Check requirements
+        if not self.type_mapping or len(self.type_mapping) != 2:
+            raise ValueError("type_mapping not set correctly for this WrapperKeepOpaque")
+
+        # Get bytes
+        bytes_obj = self.process_type("Bytes")
+        try:
+            # Try to decode bytes with wrapped SCALE type
+            wrapped_obj = self.runtime_config.create_scale_object(
+                type_string=self.type_mapping[1],
+                data=ScaleBytes(bytes_obj.value_object),
+                metadata=self.metadata
+            )
+
+            return wrapped_obj.process()
+        except:
+            # Decoding failed; return Opaque type
+            self.value_object = bytes_obj.value_object
+            return f'0x{bytes_obj.value_object.hex()}'
+
+
 class MultiAccountId(GenericAccountId):
 
     @classmethod

test/test_scale_types.py

@@ -417,6 +417,56 @@ def test_opaque_call(self):
         self.assertEqual(value['call_args'][0]['value'], '0x0123456789')
         self.assertEqual(value['call_args'][0]['name'], '_remark')
 
+    def test_wrapped_opaque_decode_success(self):
+        opaque_hex = '0x1805000022db73'
+        wrapped_obj = self.runtime_config_v14.create_scale_object(
+            type_string="WrapperKeepOpaque",
+            metadata=self.metadata_v14_obj
+        )
+        wrapped_obj.type_mapping = ("Compact<u32>", "Call")
+        wrapped_obj.decode(ScaleBytes(opaque_hex))
+        self.assertEqual("Indices", wrapped_obj.value["call_module"])
+
+    def test_wrapped_opaque_decode_fail(self):
+        opaque_hex = '0x180a000022db73'
+        wrapped_obj = self.runtime_config_v14.create_scale_object(
+            type_string="WrapperKeepOpaque",
+            metadata=self.metadata_v14_obj
+        )
+        wrapped_obj.type_mapping = ("Compact<u32>", "Call")
+        wrapped_obj.decode(ScaleBytes(opaque_hex))
+        self.assertEqual(
+            "0x0a000022db73",
+            wrapped_obj.value
+        )
+
+    def test_wrapped_opaque_decode_incorrect(self):
+        opaque_hex = '0xa405000022db73'
+        wrapped_obj = self.runtime_config_v14.create_scale_object(
+            type_string="WrapperKeepOpaque",
+            metadata=self.metadata_v14_obj
+        )
+        with self.assertRaises(ValueError):
+            wrapped_obj.decode(ScaleBytes(opaque_hex))
+
+    def test_wrapped_opaque_encode(self):
+        wrapped_obj = self.runtime_config_v14.create_scale_object(
+            type_string="WrapperKeepOpaque",
+            metadata=self.metadata_v14_obj
+        )
+        wrapped_obj.type_mapping = ("Compact<u32>", "Call")
+
+        wrapped_obj.encode({
+            'call_function': 'claim',
+            'call_module': 'Indices',
+            'call_args': {'index': 1943740928}
+        })
+
+        self.assertEqual(
+            "0x1805000022db73",
+            wrapped_obj.data.to_hex()
+        )
+
     def test_era_immortal(self):
         obj = RuntimeConfiguration().create_scale_object('Era', ScaleBytes('0x00'))
         obj.decode()