Add deserialization for certificates

Author: nielstron

pycardano/certificate.py

@@ -1,8 +1,13 @@
 from dataclasses import dataclass, field
-from typing import Optional, Union
+from typing import Optional, Union, Type
 
+from pycardano.exception import DeserializeException
 from pycardano.hash import PoolKeyHash, ScriptHash, VerificationKeyHash
-from pycardano.serialization import ArrayCBORSerializable
+from pycardano.serialization import (
+    ArrayCBORSerializable,
+    ArrayBase,
+    limit_primitive_type,
+)
 
 __all__ = [
     "Certificate",
@@ -25,20 +30,56 @@ def __post_init__(self):
         else:
             self._CODE = 1
 
+    @classmethod
+    @limit_primitive_type(list, tuple)
+    def from_primitive(
+        cls: Type[ArrayBase], values: Union[list, tuple]
+    ) -> "StakeCredential":
+        if len(values) != 2:
+            raise ValueError(f"Expected 2 values, got {len(values)}")
+        if values[0] == 0:
+            return StakeCredential(VerificationKeyHash.from_primitive(values[1]))
+        elif values[0] == 1:
+            return StakeCredential(ScriptHash.from_primitive(values[1]))
+        else:
+            raise ValueError(f"Unknown code: {values[0]}")
+
 
 @dataclass(repr=False)
 class StakeRegistration(ArrayCBORSerializable):
     _CODE: int = field(init=False, default=0)
 
     stake_credential: StakeCredential
 
+    @classmethod
+    @limit_primitive_type(list, tuple)
+    def from_primitive(
+        cls: Type[ArrayBase], values: Union[list, tuple]
+    ) -> "StakeRegistration":
+        if len(values) != 2:
+            raise DeserializeException(f"Expected 2 values, got {len(values)}")
+        if values[0] != 0:
+            raise DeserializeException(f"Expected 0, got {values[0]}")
+        return StakeRegistration(StakeCredential.from_primitive(values[1]))
+
 
 @dataclass(repr=False)
 class StakeDeregistration(ArrayCBORSerializable):
     _CODE: int = field(init=False, default=1)
 
     stake_credential: StakeCredential
 
+    @classmethod
+    @limit_primitive_type(list, tuple)
+    def from_primitive(
+        cls: Type[ArrayBase], values: Union[list, tuple]
+    ) -> "StakeDeregistration":
+        if len(values) != 2:
+            raise DeserializeException(f"Expected 2 values, got {len(values)}")
+        if values[0] != 1:
+            raise DeserializeException(f"Expected 1, got {values[0]}")
+        return StakeDeregistration(StakeCredential.from_primitive(values[1]))
+
 
 @dataclass(repr=False)
 class StakeDelegation(ArrayCBORSerializable):
@@ -48,5 +89,19 @@ class StakeDelegation(ArrayCBORSerializable):
 
     pool_keyhash: PoolKeyHash
 
+    @classmethod
+    @limit_primitive_type(list, tuple)
+    def from_primitive(
+        cls: Type[ArrayBase], values: Union[list, tuple]
+    ) -> "StakeDelegation":
+        if len(values) != 3:
+            raise DeserializeException(f"Expected 3 values, got {len(values)}")
+        if values[0] != 2:
+            raise DeserializeException(f"Expected 2, got {values[0]}")
+        return StakeDelegation(
+            StakeCredential.from_primitive(values[1]),
+            PoolKeyHash.from_primitive(values[2]),
+        )
+
 
 Certificate = Union[StakeRegistration, StakeDeregistration, StakeDelegation]

test/pycardano/test_serialization.py

@@ -316,3 +316,13 @@ def test_deserialize_empty_value():
         transaction.transaction_body.outputs[0].amount.multi_asset
         == pycardano.MultiAsset()
     ), "Invalid deserialization of multi asset"
+
+
+def test_certificate_transaction_deserialize():
+    """
+    This should not crash even though there is an empty value in the transaction
+    """
+    pycardano.Transaction.from_cbor(
+        "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"
+    )
+    # TODO add test for presence of certificate