Fix error when adding multiple redeemers (#192)

Author: cffls

pycardano/plutus.py

@@ -739,6 +739,12 @@ def __add__(self, other: ExecutionUnits) -> ExecutionUnits:
             )
         return ExecutionUnits(self.mem + other.mem, self.steps + other.steps)
 
+    def is_empty(self) -> bool:
+        return self.mem == 0 and self.steps == 0
+
+    def __bool__(self):
+        return not self.is_empty()
+
 
 @dataclass(repr=False)
 class Redeemer(ArrayCBORSerializable):

pycardano/txbuilder.py

@@ -166,15 +166,15 @@ def _consolidate_redeemer(self, redeemer):
                 self._should_estimate_execution_units = True
                 redeemer.ex_units = ExecutionUnits(0, 0)
         else:
-            if not self._should_estimate_execution_units and redeemer.ex_units is None:
+            if not self._should_estimate_execution_units and not redeemer.ex_units:
                 raise InvalidArgumentException(
                     f"All redeemers need to provide execution units if the firstly "
                     f"added redeemer specifies execution units. \n"
                     f"Added redeemers: {self.redeemers} \n"
                     f"New redeemer: {redeemer}"
                 )
             if self._should_estimate_execution_units:
-                if redeemer.ex_units is not None:
+                if redeemer.ex_units:
                     raise InvalidArgumentException(
                         f"No redeemer should provide execution units if the firstly "
                         f"added redeemer didn't provide execution units. \n"

test/pycardano/test_plutus.py

@@ -208,6 +208,15 @@ def test_plutus_data_hash():
     )
 
 
+def test_execution_units_bool():
+    assert ExecutionUnits(
+        1000000, 1000000
+    ), "ExecutionUnits should be true when its value is not 0"
+    assert not ExecutionUnits(
+        0, 0
+    ), "ExecutionUnits should be false when its value is 0"
+
+
 def test_redeemer():
     data = MyTest(123, b"234", IndefiniteList([4, 5, 6]), {1: b"1", 2: b"2"})
     redeemer = MyRedeemer(data, ExecutionUnits(1000000, 1000000))

test/pycardano/test_txbuilder.py

@@ -585,6 +585,89 @@ def test_add_script_input_with_script_from_specified_utxo(chain_context):
     assert [existing_script_utxo.input] == tx_body.reference_inputs
 
 
+def test_add_script_input_multiple_redeemers(chain_context):
+    tx_builder = TransactionBuilder(chain_context)
+    tx_in1 = TransactionInput.from_primitive(
+        ["18cbe6cadecd3f89b60e08e68e5e6c7d72d730aaa1ad21431590f7e6643438ef", 0]
+    )
+    tx_in2 = TransactionInput.from_primitive(
+        ["18cbe6cadecd3f89b60e08e68e5e6c7d72d730aaa1ad21431590f7e6643438ef", 1]
+    )
+    plutus_script = PlutusV2Script(b"dummy test script")
+    script_hash = plutus_script_hash(plutus_script)
+    script_address = Address(script_hash)
+    datum = PlutusData()
+    utxo1 = UTxO(
+        tx_in1, TransactionOutput(script_address, 10000000, datum_hash=datum.hash())
+    )
+
+    existing_script_utxo = UTxO(
+        TransactionInput.from_primitive(
+            [
+                "41cb004bec7051621b19b46aea28f0657a586a05ce2013152ea9b9f1a5614cc7",
+                1,
+            ]
+        ),
+        TransactionOutput(script_address, 1234567, script=plutus_script),
+    )
+
+    utxo2 = UTxO(
+        tx_in2, TransactionOutput(script_address, 10000000, datum_hash=datum.hash())
+    )
+
+    existing_script_utxo = UTxO(
+        TransactionInput.from_primitive(
+            [
+                "41cb004bec7051621b19b46aea28f0657a586a05ce2013152ea9b9f1a5614cc7",
+                1,
+            ]
+        ),
+        TransactionOutput(script_address, 1234567, script=plutus_script),
+    )
+
+    tx_builder.add_script_input(
+        utxo1, script=existing_script_utxo, datum=datum, redeemer=Redeemer(PlutusData())
+    )
+
+    tx_builder.add_script_input(
+        utxo2, script=existing_script_utxo, datum=datum, redeemer=Redeemer(PlutusData())
+    )
+
+    pytest.raises(
+        InvalidArgumentException,
+        tx_builder.add_script_input,
+        utxo2,
+        script=existing_script_utxo,
+        datum=datum,
+        redeemer=Redeemer(PlutusData(), ExecutionUnits(1000000, 1000000)),
+    )
+
+    tx_builder = TransactionBuilder(chain_context)
+
+    tx_builder.add_script_input(
+        utxo1,
+        script=existing_script_utxo,
+        datum=datum,
+        redeemer=Redeemer(PlutusData(), ExecutionUnits(1000000, 1000000)),
+    )
+
+    tx_builder.add_script_input(
+        utxo2,
+        script=existing_script_utxo,
+        datum=datum,
+        redeemer=Redeemer(PlutusData(), ExecutionUnits(1000000, 1000000)),
+    )
+
+    pytest.raises(
+        InvalidArgumentException,
+        tx_builder.add_script_input,
+        utxo2,
+        script=existing_script_utxo,
+        datum=datum,
+        redeemer=Redeemer(PlutusData()),
+    )
+
+
 def test_add_minting_script_from_specified_utxo(chain_context):
     tx_builder = TransactionBuilder(chain_context)
     plutus_script = PlutusV2Script(b"dummy test script")