Remove the need to specify the RedeemerTag (#178)

* Remove the need to specify the RedeemerTag

This reduces friction for writing applications

* Default initialize the tag to SPEND

TODO I would rather set it to None, so that we catch situations where it
is incorrectly initialized

* Initialize to None

* Formatting

Author: nielstron

examples/plutus/forty_two/forty_two.py

@@ -94,7 +94,7 @@ def create_collateral(target_address, skey):
 # Notice that transaction builder will automatically estimate execution units (num steps & memory) for a redeemer if
 # no execution units are provided in the constructor of Redeemer.
 # Put integer 42 (the secret that unlocks the fund) in the redeemer.
-redeemer = Redeemer(RedeemerTag.SPEND, 42)
+redeemer = Redeemer(42)
 
 utxo_to_spend = None
 for utxo in chain_context.utxos(str(script_address)):

integration-test/test/test_min_utxo.py

@@ -66,7 +66,7 @@ class MyPlutusData(PlutusData):
 
         # Add minting script with an empty datum and a minting redeemer
         builder.add_minting_script(
-            anymint_script, redeemer=Redeemer(RedeemerTag.MINT, MyPlutusData(a=42))
+            anymint_script, redeemer=Redeemer(MyPlutusData(a=42))
         )
 
         # Set nft we want to mint

integration-test/test/test_mint.py

@@ -214,9 +214,7 @@ def test_mint_nft_with_script(self):
         builder.add_input_address(address)
 
         # Add minting script with an empty datum and a minting redeemer
-        builder.add_minting_script(
-            forty_two_script, redeemer=Redeemer(RedeemerTag.MINT, 42)
-        )
+        builder.add_minting_script(forty_two_script, redeemer=Redeemer(42))
 
         # Set nft we want to mint
         builder.mint = my_nft
@@ -311,7 +309,7 @@ class MyPlutusData(PlutusData):
 
         # Add minting script with an empty datum and a minting redeemer
         builder.add_minting_script(
-            anymint_script, redeemer=Redeemer(RedeemerTag.MINT, MyPlutusData(a=42))
+            anymint_script, redeemer=Redeemer(MyPlutusData(a=42))
         )
 
         # Set nft we want to mint

integration-test/test/test_plutus.py

@@ -61,7 +61,7 @@ def test_plutus_v1(self):
 
         # ----------- Taker take ---------------
 
-        redeemer = Redeemer(RedeemerTag.SPEND, 42)
+        redeemer = Redeemer(42)
 
         utxo_to_spend = self.chain_context.utxos(str(script_address))[0]
 
@@ -128,7 +128,7 @@ def test_plutus_v2_datum_hash(self):
 
         # ----------- Taker take ---------------
 
-        redeemer = Redeemer(RedeemerTag.SPEND, 42)
+        redeemer = Redeemer(42)
 
         utxo_to_spend = None
 
@@ -206,7 +206,7 @@ def test_plutus_v2_inline_script_inline_datum(self):
 
         # ----------- Taker take ---------------
 
-        redeemer = Redeemer(RedeemerTag.SPEND, 42)
+        redeemer = Redeemer(42)
 
         utxo_to_spend = None
 
@@ -285,7 +285,7 @@ def test_plutus_v2_ref_script(self):
 
         # ----------- Taker take ---------------
 
-        redeemer = Redeemer(RedeemerTag.SPEND, 42)
+        redeemer = Redeemer(42)
 
         utxo_to_spend = None
 

pycardano/plutus.py

@@ -697,7 +697,7 @@ def __add__(self, other: ExecutionUnits) -> ExecutionUnits:
 
 @dataclass(repr=False)
 class Redeemer(ArrayCBORSerializable):
-    tag: RedeemerTag
+    tag: Optional[RedeemerTag] = field(default=None, init=False)
 
     index: int = field(default=0, init=False)
 
@@ -710,9 +710,8 @@ class Redeemer(ArrayCBORSerializable):
     def from_primitive(cls: Type[Redeemer], values: list) -> Redeemer:
         if isinstance(values[2], CBORTag) and cls is Redeemer:
             values[2] = RawPlutusData.from_primitive(values[2])
-        redeemer = super(Redeemer, cls).from_primitive(
-            [values[0], values[2], values[3]]
-        )
+        redeemer = super(Redeemer, cls).from_primitive([values[2], values[3]])
+        redeemer.tag = RedeemerTag.from_primitive(values[0])
         redeemer.index = values[1]
         return redeemer
 

pycardano/txbuilder.py

@@ -226,6 +226,12 @@ def add_script_input(
             self.datums[datum_hash(datum)] = datum
 
         if redeemer:
+            if redeemer.tag is not None and redeemer.tag != RedeemerTag.SPEND:
+                raise InvalidArgumentException(
+                    f"Expect the redeemer tag's type to be {RedeemerTag.SPEND}, "
+                    f"but got {redeemer.tag} instead."
+                )
+            redeemer.tag = RedeemerTag.SPEND
             self._consolidate_redeemer(redeemer)
             self._inputs_to_redeemers[utxo] = redeemer
 
@@ -266,11 +272,12 @@ def add_minting_script(
             TransactionBuilder: Current transaction builder.
         """
         if redeemer:
-            if redeemer.tag != RedeemerTag.MINT:
+            if redeemer.tag is not None and redeemer.tag != RedeemerTag.MINT:
                 raise InvalidArgumentException(
                     f"Expect the redeemer tag's type to be {RedeemerTag.MINT}, "
                     f"but got {redeemer.tag} instead."
                 )
+            redeemer.tag = RedeemerTag.MINT
             self._consolidate_redeemer(redeemer)
 
         if isinstance(script, UTxO):
@@ -1119,6 +1126,9 @@ def _update_execution_units(
                 change_address, merge_change, collateral_change_address
             )
             for r in self.redeemers:
+                assert (
+                    r.tag is not None
+                ), "Expected tag of redeemer to be set, but found None"
                 key = f"{r.tag.name.lower()}:{r.index}"
                 if (
                     key not in estimated_execution_units

test/pycardano/test_plutus.py

@@ -1,6 +1,6 @@
-from dataclasses import dataclass
+from dataclasses import dataclass, field
 from test.pycardano.util import check_two_way_cbor
-from typing import Union
+from typing import Union, Optional
 
 import pytest
 
@@ -152,7 +152,8 @@ def test_plutus_data_hash():
 
 def test_redeemer():
     data = MyTest(123, b"234", IndefiniteList([4, 5, 6]), {1: b"1", 2: b"2"})
-    redeemer = MyRedeemer(RedeemerTag.SPEND, data, ExecutionUnits(1000000, 1000000))
+    redeemer = MyRedeemer(data, ExecutionUnits(1000000, 1000000))
+    redeemer.tag = RedeemerTag.SPEND
     assert (
         "840000d8668218829f187b433233349f040506ffa2014131024132ff821a000f42401a000f4240"
         == redeemer.to_cbor()
@@ -162,7 +163,8 @@ def test_redeemer():
 
 def test_redeemer_empty_datum():
     data = MyTest(123, b"234", IndefiniteList([]), {1: b"1", 2: b"2"})
-    redeemer = MyRedeemer(RedeemerTag.SPEND, data, ExecutionUnits(1000000, 1000000))
+    redeemer = MyRedeemer(data, ExecutionUnits(1000000, 1000000))
+    redeemer.tag = RedeemerTag.SPEND
     assert (
         "840000d8668218829f187b433233349fffa2014131024132ff821a000f42401a000f4240"
         == redeemer.to_cbor()

test/pycardano/test_txbuilder.py

@@ -455,15 +455,11 @@ def test_add_script_input(chain_context):
             script_address, Value(10000000, mint), datum_hash=datum.hash()
         ),
     )
-    redeemer1 = Redeemer(
-        RedeemerTag.SPEND, PlutusData(), ExecutionUnits(1000000, 1000000)
-    )
-    redeemer2 = Redeemer(
-        RedeemerTag.MINT, PlutusData(), ExecutionUnits(1000000, 1000000)
-    )
+    redeemer1 = Redeemer(PlutusData(), ExecutionUnits(1000000, 1000000))
+    redeemer2 = Redeemer(PlutusData(), ExecutionUnits(5000000, 1000000))
     tx_builder.mint = mint
     tx_builder.add_script_input(utxo1, plutus_script, datum, redeemer1)
-    tx_builder.add_script_input(utxo2, plutus_script, datum, redeemer2)
+    tx_builder.add_minting_script(plutus_script, redeemer2)
     receiver = Address.from_primitive(
         "addr_test1vrm9x2zsux7va6w892g38tvchnzahvcd9tykqf3ygnmwtaqyfg52x"
     )
@@ -490,9 +486,7 @@ def test_add_script_input_no_script(chain_context):
             script_address, 10000000, datum_hash=datum.hash(), script=plutus_script
         ),
     )
-    redeemer = Redeemer(
-        RedeemerTag.SPEND, PlutusData(), ExecutionUnits(1000000, 1000000)
-    )
+    redeemer = Redeemer(PlutusData(), ExecutionUnits(1000000, 1000000))
     tx_builder.add_script_input(utxo1, datum=datum, redeemer=redeemer)
     receiver = Address.from_primitive(
         "addr_test1vrm9x2zsux7va6w892g38tvchnzahvcd9tykqf3ygnmwtaqyfg52x"
@@ -534,9 +528,7 @@ def test_add_script_input_find_script(chain_context):
 
         mock_utxos.return_value = original_utxos + [existing_script_utxo]
 
-        redeemer = Redeemer(
-            RedeemerTag.SPEND, PlutusData(), ExecutionUnits(1000000, 1000000)
-        )
+        redeemer = Redeemer(PlutusData(), ExecutionUnits(1000000, 1000000))
         tx_builder.add_script_input(utxo1, datum=datum, redeemer=redeemer)
         receiver = Address.from_primitive(
             "addr_test1vrm9x2zsux7va6w892g38tvchnzahvcd9tykqf3ygnmwtaqyfg52x"
@@ -573,9 +565,7 @@ def test_add_script_input_with_script_from_specified_utxo(chain_context):
         TransactionOutput(script_address, 1234567, script=plutus_script),
     )
 
-    redeemer = Redeemer(
-        RedeemerTag.SPEND, PlutusData(), ExecutionUnits(1000000, 1000000)
-    )
+    redeemer = Redeemer(PlutusData(), ExecutionUnits(1000000, 1000000))
     tx_builder.add_script_input(
         utxo1, script=existing_script_utxo, datum=datum, redeemer=redeemer
     )
@@ -609,9 +599,7 @@ def test_add_minting_script_from_specified_utxo(chain_context):
 
     mint = MultiAsset.from_primitive({script_hash.payload: {b"TestToken": 1}})
 
-    redeemer = Redeemer(
-        RedeemerTag.MINT, PlutusData(), ExecutionUnits(1000000, 1000000)
-    )
+    redeemer = Redeemer(PlutusData(), ExecutionUnits(1000000, 1000000))
     tx_builder.add_minting_script(existing_script_utxo, redeemer=redeemer)
     receiver = Address.from_primitive(
         "addr_test1vrm9x2zsux7va6w892g38tvchnzahvcd9tykqf3ygnmwtaqyfg52x"
@@ -662,9 +650,7 @@ def test_collateral_return(chain_context):
 
         mock_utxos.return_value = original_utxos + [existing_script_utxo]
 
-        redeemer = Redeemer(
-            RedeemerTag.SPEND, PlutusData(), ExecutionUnits(1000000, 1000000)
-        )
+        redeemer = Redeemer(PlutusData(), ExecutionUnits(1000000, 1000000))
         tx_builder.add_script_input(utxo1, datum=datum, redeemer=redeemer)
         receiver = Address.from_primitive(
             "addr_test1vrm9x2zsux7va6w892g38tvchnzahvcd9tykqf3ygnmwtaqyfg52x"
@@ -700,16 +686,14 @@ def test_wrong_redeemer_execution_units(chain_context):
             script_address, Value(10000000, mint), datum_hash=datum.hash()
         ),
     )
-    redeemer1 = Redeemer(RedeemerTag.SPEND, PlutusData())
-    redeemer2 = Redeemer(RedeemerTag.MINT, PlutusData())
-    redeemer3 = Redeemer(
-        RedeemerTag.MINT, PlutusData(), ExecutionUnits(1000000, 1000000)
-    )
+    redeemer1 = Redeemer(PlutusData())
+    redeemer2 = Redeemer(PlutusData())
+    redeemer3 = Redeemer(PlutusData(), ExecutionUnits(1000000, 1000000))
     tx_builder.mint = mint
     tx_builder.add_script_input(utxo1, plutus_script, datum, redeemer1)
-    tx_builder.add_script_input(utxo1, plutus_script, datum, redeemer2)
+    tx_builder.add_minting_script(plutus_script, redeemer2)
     with pytest.raises(InvalidArgumentException):
-        tx_builder.add_script_input(utxo2, plutus_script, datum, redeemer3)
+        tx_builder.add_minting_script(plutus_script, redeemer3)
 
 
 def test_all_redeemer_should_provide_execution_units(chain_context):
@@ -728,10 +712,8 @@ def test_all_redeemer_should_provide_execution_units(chain_context):
         tx_in1, TransactionOutput(script_address, 10000000, datum_hash=datum.hash())
     )
     mint = MultiAsset.from_primitive({script_hash.payload: {b"TestToken": 1}})
-    redeemer1 = Redeemer(
-        RedeemerTag.SPEND, PlutusData(), ExecutionUnits(1000000, 1000000)
-    )
-    redeemer2 = Redeemer(RedeemerTag.MINT, PlutusData())
+    redeemer1 = Redeemer(PlutusData(), ExecutionUnits(1000000, 1000000))
+    redeemer2 = Redeemer(PlutusData())
     tx_builder.mint = mint
     tx_builder.add_script_input(utxo1, plutus_script, datum, redeemer1)
     with pytest.raises(InvalidArgumentException):
@@ -748,9 +730,7 @@ def test_add_minting_script(chain_context):
     script_address = Address(script_hash)
     utxo1 = UTxO(tx_in1, TransactionOutput(script_address, 10000000))
     mint = MultiAsset.from_primitive({script_hash.payload: {b"TestToken": 1}})
-    redeemer1 = Redeemer(
-        RedeemerTag.MINT, PlutusData(), ExecutionUnits(1000000, 1000000)
-    )
+    redeemer1 = Redeemer(PlutusData(), ExecutionUnits(1000000, 1000000))
     tx_builder.mint = mint
     tx_builder.add_input(utxo1)
     tx_builder.add_minting_script(plutus_script, redeemer1)
@@ -766,9 +746,8 @@ def test_add_minting_script(chain_context):
 def test_add_minting_script_wrong_redeemer_type(chain_context):
     tx_builder = TransactionBuilder(chain_context)
     plutus_script = PlutusV1Script(b"dummy test script")
-    redeemer1 = Redeemer(
-        RedeemerTag.SPEND, PlutusData(), ExecutionUnits(1000000, 1000000)
-    )
+    redeemer1 = Redeemer(PlutusData(), ExecutionUnits(1000000, 1000000))
+    redeemer1.tag = RedeemerTag.SPEND
 
     with pytest.raises(InvalidArgumentException):
         tx_builder.add_minting_script(plutus_script, redeemer1)
@@ -853,7 +832,7 @@ def test_estimate_execution_unit(chain_context):
         tx_in1, TransactionOutput(script_address, 10000000, datum_hash=datum.hash())
     )
     mint = MultiAsset.from_primitive({script_hash.payload: {b"TestToken": 1}})
-    redeemer1 = Redeemer(RedeemerTag.SPEND, PlutusData())
+    redeemer1 = Redeemer(PlutusData())
     tx_builder.mint = mint
     tx_builder.add_script_input(utxo1, plutus_script, datum, redeemer1)
     receiver = Address.from_primitive(

test/pycardano/test_util.py

@@ -147,7 +147,8 @@ def test_min_lovelace_multi_asset_9(self, chain_context):
 
 def test_script_data_hash():
     unit = PlutusData()
-    redeemers = [Redeemer(RedeemerTag.SPEND, unit, ExecutionUnits(1000000, 1000000))]
+    redeemers = [Redeemer(unit, ExecutionUnits(1000000, 1000000))]
+    redeemers[0].tag = RedeemerTag.SPEND
     assert ScriptDataHash.from_primitive(
         "032d812ee0731af78fe4ec67e4d30d16313c09e6fb675af28f825797e8b5621d"
     ) == script_data_hash(redeemers=redeemers, datums=[unit])