Allow users to configure the serialization format for redeemers

Author: cffls

pycardano/txbuilder.py

@@ -124,6 +124,9 @@ class TransactionBuilder:
 
     initial_stake_pool_registration: Optional[bool] = field(default=False)
 
+    use_redeemer_map: Optional[bool] = field(default=True)
+    """Whether to serialize redeemers as a map or a list. Default is True."""
+
     _inputs: List[UTxO] = field(init=False, default_factory=lambda: [])
 
     _potential_inputs: List[UTxO] = field(init=False, default_factory=lambda: [])
@@ -496,21 +499,27 @@ def _redeemer_list(self) -> List[Redeemer]:
             + [r for _, r in self._withdrawal_script_to_redeemers if r is not None]
         )
 
-    def redeemers(self) -> RedeemerMap:
-        redeemers = RedeemerMap()
-        for r in self._redeemer_list:
-            if r.tag is None:
-                raise InvalidArgumentException(
-                    f"Redeemer tag is not set. Redeemer: {r}"
-                )
-            if r.ex_units is None:
-                raise InvalidArgumentException(
-                    f"Execution units are not set. Redeemer: {r}"
-                )
-            k = RedeemerKey(r.tag, r.index)
-            v = RedeemerValue(r.data, r.ex_units)
-            redeemers[k] = v
-        return redeemers
+    def redeemers(self) -> Redeemers:
+        redeemer_list = self._redeemer_list
+
+        # We have to serialize redeemers as a map if there are no redeemers
+        if self.use_redeemer_map or not redeemer_list:
+            redeemers = RedeemerMap()
+            for r in redeemer_list:
+                if r.tag is None:
+                    raise InvalidArgumentException(
+                        f"Redeemer tag is not set. Redeemer: {r}"
+                    )
+                if r.ex_units is None:
+                    raise InvalidArgumentException(
+                        f"Execution units are not set. Redeemer: {r}"
+                    )
+                k = RedeemerKey(r.tag, r.index)
+                v = RedeemerValue(r.data, r.ex_units)
+                redeemers[k] = v
+            return redeemers
+        else:
+            return redeemer_list
 
     @property
     def script_data_hash(self) -> Optional[ScriptDataHash]:
@@ -971,15 +980,14 @@ def _build_full_fake_tx(self) -> Transaction:
         return tx
 
     def build_witness_set(
-        self, remove_dup_script: bool = False, post_chang: bool = True
+        self, remove_dup_script: bool = False
     ) -> TransactionWitnessSet:
         """Build a transaction witness set, excluding verification key witnesses.
         This function is especially useful when the transaction involves Plutus scripts.
 
         Args:
             remove_dup_script (bool): Whether to remove scripts, that are already attached to inputs,
              from the witness set.
-            post_chang (bool): Whether to use chang serialization for the witness.
 
         Returns:
             TransactionWitnessSet: A transaction witness set without verification key witnesses.
@@ -1017,19 +1025,12 @@ def build_witness_set(
                         f"Unsupported script type: {type(script)}"
                     )
 
-        redeemers: Optional[Redeemers] = None
-        if self._redeemer_list:
-            if not post_chang:
-                redeemers = self._redeemer_list
-            else:
-                redeemers = self.redeemers()
-
         return TransactionWitnessSet(
             native_scripts=native_scripts if native_scripts else None,
             plutus_v1_script=plutus_v1_scripts if plutus_v1_scripts else None,
             plutus_v2_script=plutus_v2_scripts if plutus_v2_scripts else None,
             plutus_v3_script=plutus_v3_scripts if plutus_v3_scripts else None,
-            redeemer=redeemers,
+            redeemer=self.redeemers() if self._redeemer_list else None,
             plutus_data=list(self.datums.values()) if self.datums else None,
         )
 

test/pycardano/test_txbuilder.py

@@ -572,7 +572,8 @@ def test_add_script_input(chain_context):
     )
     tx_builder.add_output(TransactionOutput(receiver, 5000000))
     tx_builder.build(change_address=receiver)
-    witness = tx_builder.build_witness_set(post_chang=False)
+    tx_builder.use_redeemer_map = False
+    witness = tx_builder.build_witness_set()
     assert [datum] == witness.plutus_data
     assert [redeemer1, redeemer2] == witness.redeemer
     assert [plutus_script] == witness.plutus_v1_script
@@ -603,7 +604,8 @@ def test_add_script_input_no_script(chain_context):
     )
     tx_builder.add_output(TransactionOutput(receiver, 5000000))
     tx_builder.build(change_address=receiver)
-    witness = tx_builder.build_witness_set(remove_dup_script=True, post_chang=False)
+    tx_builder.use_redeemer_map = False
+    witness = tx_builder.build_witness_set(remove_dup_script=True, )
     assert [datum] == witness.plutus_data
     assert [redeemer] == witness.redeemer
     assert witness.plutus_v1_script is None
@@ -671,7 +673,8 @@ def test_add_script_input_find_script(chain_context):
         )
         tx_builder.add_output(TransactionOutput(receiver, 5000000))
         tx_body = tx_builder.build(change_address=receiver)
-        witness = tx_builder.build_witness_set(post_chang=False)
+        tx_builder.use_redeemer_map = False
+        witness = tx_builder.build_witness_set()
         assert [datum] == witness.plutus_data
         assert [redeemer] == witness.redeemer
         assert witness.plutus_v1_script is None
@@ -710,7 +713,8 @@ def test_add_script_input_with_script_from_specified_utxo(chain_context):
     )
     tx_builder.add_output(TransactionOutput(receiver, 5000000))
     tx_body = tx_builder.build(change_address=receiver)
-    witness = tx_builder.build_witness_set(post_chang=False)
+    tx_builder.use_redeemer_map = False
+    witness = tx_builder.build_witness_set()
     assert [datum] == witness.plutus_data
     assert [redeemer] == witness.redeemer
     assert witness.plutus_v2_script is None
@@ -981,7 +985,8 @@ def test_add_minting_script_from_specified_utxo(chain_context):
     tx_builder.add_output(TransactionOutput(receiver, 5000000))
     tx_builder.mint = mint
     tx_body = tx_builder.build(change_address=receiver)
-    witness = tx_builder.build_witness_set(post_chang=False)
+    tx_builder.use_redeemer_map = False
+    witness = tx_builder.build_witness_set()
     assert witness.plutus_data is None
     assert [redeemer] == witness.redeemer
     assert witness.plutus_v2_script is None
@@ -1110,7 +1115,8 @@ def test_add_minting_script(chain_context):
     )
     tx_builder.add_output(TransactionOutput(receiver, Value(5000000, mint)))
     tx_builder.build(change_address=receiver)
-    witness = tx_builder.build_witness_set(post_chang=False)
+    tx_builder.use_redeemer_map = False
+    witness = tx_builder.build_witness_set()
     assert [plutus_script] == witness.plutus_v1_script
 
 
@@ -1132,7 +1138,8 @@ def test_add_minting_script_only(chain_context):
     )
     tx_builder.add_output(TransactionOutput(receiver, Value(5000000, mint)))
     tx_builder.build(change_address=receiver)
-    witness = tx_builder.build_witness_set(post_chang=False)
+    tx_builder.use_redeemer_map = False
+    witness = tx_builder.build_witness_set()
     assert [plutus_script] == witness.plutus_v1_script
 
 
@@ -1237,7 +1244,8 @@ def test_estimate_execution_unit(chain_context):
     )
     tx_builder.add_output(TransactionOutput(receiver, 5000000))
     tx_builder.build(change_address=receiver)
-    witness = tx_builder.build_witness_set(post_chang=False)
+    tx_builder.use_redeemer_map = False
+    witness = tx_builder.build_witness_set()
     assert [datum] == witness.plutus_data
     assert [redeemer1] == witness.redeemer
     assert redeemer1.ex_units is not None