Move validate_payable check inside web3.utils.prepare_transaction

web3/contract.py

@@ -29,7 +29,6 @@
     MismatchedABI,
     NoABIEventsFound,
     NoABIFunctionsFound,
-    ValidationError,
 )
 from web3.utils.abi import (
     abi_to_signature,
@@ -1354,11 +1353,6 @@ def call_contract_function(
     Helper function for interacting with a contract function using the
     `eth_call` API.
     """
-    if fn_abi is None:
-        fn_abi = find_matching_fn_abi(contract_abi, function_identifier, args, kwargs)
-
-    validate_payable(transaction, fn_abi)
-
     call_transaction = prepare_transaction(
         address,
         web3,
@@ -1375,6 +1369,9 @@ def call_contract_function(
     else:
         return_data = web3.eth.call(call_transaction, block_identifier=block_id)
 
+    if fn_abi is None:
+        fn_abi = find_matching_fn_abi(contract_abi, function_identifier, args, kwargs)
+
     output_types = get_abi_output_types(fn_abi)
 
     try:
@@ -1449,12 +1446,6 @@ def transact_with_contract_function(
     Helper function for interacting with a contract function by sending a
     transaction.
     """
-
-    if fn_abi is None:
-        fn_abi = find_matching_fn_abi(contract_abi, function_name, args, kwargs)
-
-    validate_payable(transaction, fn_abi)
-
     transact_transaction = prepare_transaction(
         address,
         web3,
@@ -1484,12 +1475,6 @@ def estimate_gas_for_function(
     Don't call this directly, instead use :meth:`Contract.estimateGas`
     on your contract instance.
     """
-
-    if fn_abi is None:
-        fn_abi = find_matching_fn_abi(contract_abi, fn_identifier, args, kwargs)
-
-    validate_payable(transaction, fn_abi)
-
     estimate_transaction = prepare_transaction(
         address,
         web3,
@@ -1519,12 +1504,6 @@ def build_transaction_for_function(
     Don't call this directly, instead use :meth:`Contract.buildTransaction`
     on your contract instance.
     """
-
-    if fn_abi is None:
-        fn_abi = find_matching_fn_abi(contract_abi, function_name, args, kwargs)
-
-    validate_payable(transaction, fn_abi)
-
     prepared_transaction = prepare_transaction(
         address,
         web3,
@@ -1568,17 +1547,3 @@ def get_function_by_identifier(fns, identifier):
             'Could not find any function with matching {0}'.format(identifier)
         )
     return fns[0]
-
-
-def validate_payable(transaction, abi):
-    """Raise ValidationError if non-zero ether
-    is sent to a non payable function.
-    """
-    if 'value' in transaction:
-        if transaction['value'] != 0:
-            if "payable" in abi and not abi["payable"]:
-                raise ValidationError(
-                    "Sending non-zero ether to a contract function "
-                    "with payable=False. Please ensure that "
-                    "transaction's value is 0."
-                )

web3/utils/contracts.py

@@ -182,6 +182,11 @@ def prepare_transaction(
     TODO: make this a public API
     TODO: add new prepare_deploy_transaction API
     """
+    if fn_abi is None:
+        fn_abi = find_matching_fn_abi(contract_abi, fn_identifier, fn_args, fn_kwargs)
+
+    validate_payable(transaction, fn_abi)
+
     if transaction is None:
         prepared_transaction = {}
     else:
@@ -245,3 +250,17 @@ def get_function_info(fn_name, contract_abi=None, fn_abi=None, args=None, kwargs
     fn_arguments = merge_args_and_kwargs(fn_abi, args, kwargs)
 
     return fn_abi, fn_selector, fn_arguments
+
+
+def validate_payable(transaction, abi):
+    """Raise ValidationError if non-zero ether
+    is sent to a non payable function.
+    """
+    if 'value' in transaction:
+        if transaction['value'] != 0:
+            if "payable" in abi and not abi["payable"]:
+                raise ValidationError(
+                    "Sending non-zero ether to a contract function "
+                    "with payable=False. Please ensure that "
+                    "transaction's value is 0."
+                )