refactor: move transaction validation to occur during building and signing

Author: daniel-makerx

src/algokit_transact/ops/validate.py

@@ -18,7 +18,9 @@
     MAX_LOCAL_STATE_KEYS,
     MAX_OVERALL_REFERENCES,
     PROGRAM_PAGE_SIZE,
+    SIGNATURE_BYTE_LENGTH,
 )
+from algokit_transact import SignedTransaction
 from algokit_transact.exceptions import TransactionValidationError
 from algokit_transact.models.app_call import AppCallTransactionFields
 from algokit_transact.models.asset_config import AssetConfigTransactionFields
@@ -55,6 +57,19 @@ def _issue(
     return ValidationIssue(code=code, message=message, field=field, context=context)
 
 
+def validate_signed_transaction(stx: SignedTransaction) -> None:
+    validate_transaction(stx.txn)
+
+    signatures = {stx.sig, stx.msig, stx.lsig} - {None}
+    if not signatures:
+        raise ValueError("At least one signature type must be set")
+    if len(signatures) > 1:
+        raise ValueError("Only one signature type can be set")
+
+    if stx.sig is not None and len(stx.sig) != SIGNATURE_BYTE_LENGTH:
+        raise ValueError("Signature must be 64 bytes")
+
+
 def validate_transaction(transaction: Transaction) -> None:
     if not transaction.sender:
         raise TransactionValidationError("Transaction sender is required")

src/algokit_utils/transactions/builders/common.py

@@ -3,6 +3,7 @@
 from typing import Protocol, runtime_checkable
 
 from algokit_algod_client import models as algod_models
+from algokit_transact import validate_transaction
 from algokit_transact.models.app_call import AppCallTransactionFields
 from algokit_transact.models.asset_config import AssetConfigTransactionFields
 from algokit_transact.models.asset_freeze import AssetFreezeTransactionFields
@@ -119,7 +120,7 @@ def build_transaction(
     application_call: AppCallTransactionFields | None = None,
     key_registration: KeyRegistrationTransactionFields | None = None,
 ) -> Transaction:
-    return Transaction(
+    txn = Transaction(
         transaction_type=txn_type,
         sender=header.sender,
         first_valid=header.first_valid,
@@ -136,6 +137,8 @@ def build_transaction(
         application_call=application_call,
         key_registration=key_registration,
     )
+    validate_transaction(txn)
+    return txn
 
 
 def apply_transaction_fees(

src/algokit_utils/transactions/transaction_composer.py

@@ -1,7 +1,7 @@
 import base64
 import json
 import re
-from collections.abc import Callable, Iterable, Sequence
+from collections.abc import Callable, Sequence
 from dataclasses import dataclass, replace
 from typing import Any, TypeAlias, TypedDict, cast
 
@@ -10,14 +10,14 @@
 from algokit_algod_client import models as algod_models
 from algokit_algod_client.exceptions import UnexpectedStatusError
 from algokit_algod_client.models import SimulateTransactionResult
-from algokit_common.constants import MAX_TRANSACTION_GROUP_SIZE, SIGNATURE_BYTE_LENGTH
+from algokit_common.constants import MAX_TRANSACTION_GROUP_SIZE
 from algokit_transact import decode_signed_transaction, encode_signed_transactions, make_empty_transaction_signer
 from algokit_transact.models.signed_transaction import SignedTransaction
 from algokit_transact.models.transaction import Transaction, TransactionType
 from algokit_transact.ops.fees import calculate_fee
 from algokit_transact.ops.group import group_transactions
 from algokit_transact.ops.ids import get_transaction_id
-from algokit_transact.ops.validate import validate_transaction
+from algokit_transact.ops.validate import validate_signed_transaction, validate_transaction
 from algokit_transact.signer import AddressWithTransactionSigner, TransactionSigner
 from algokit_utils.applications.abi import ABIReturn
 from algokit_utils.applications.app_manager import AppManager
@@ -293,6 +293,7 @@ def register_error_transformer(self, transformer: ErrorTransformer) -> "Transact
         return self
 
     def add_transaction(self, txn: Transaction, signer: TransactionSigner | None = None) -> "TransactionComposer":
+        validate_transaction(txn)
         self._ensure_not_built()
         self._queued.append(_QueuedTransaction(txn=self._sanitize_transaction(txn), signer=signer))
         return self
@@ -501,7 +502,6 @@ def send(self, params: SendParams | None = None) -> SendTransactionComposerResul
 
         # Send transactions and handle network errors
         try:
-            _validate_signed_transactions(signed_transactions)
             blobs = encode_signed_transactions(signed_transactions)
             self._algod.send_raw_transaction(blobs)
 
@@ -1370,7 +1370,9 @@ def _sign_transactions(self, txns_with_signers: Sequence[TransactionWithSigner])
         for key, (_, indexes) in signer_groups.items():
             blobs = signed_blobs[key]
             for blob_index, txn_index in enumerate(indexes):
-                ordered[txn_index] = decode_signed_transaction(blobs[blob_index])
+                signed_txn = decode_signed_transaction(blobs[blob_index])
+                validate_signed_transaction(signed_txn)
+                ordered[txn_index] = signed_txn
 
         if any(item is None for item in ordered):
             raise ValueError("One or more transactions were not signed")
@@ -1557,24 +1559,6 @@ def _extract_algod_error_message(payload: object) -> str | None:  # noqa: PLR091
         return text
 
 
-def _validate_signed_transactions(stxns: Iterable[SignedTransaction]) -> None:
-    for stxn in stxns:
-        _validate_signed_transaction(stxn)
-
-
-def _validate_signed_transaction(stx: SignedTransaction) -> None:
-    validate_transaction(stx.txn)
-
-    signatures = {stx.sig, stx.msig, stx.lsig} - {None}
-    if not signatures:
-        raise ValueError("At least one signature type must be set")
-    if len(signatures) > 1:
-        raise ValueError("Only one signature type can be set")
-
-    if stx.sig is not None and len(stx.sig) != SIGNATURE_BYTE_LENGTH:
-        raise ValueError("Signature must be 64 bytes")
-
-
 def _wait_for_confirmation(
     algod: AlgodClient,
     tx_id: str,

tests/transactions/test_transaction_composer.py

@@ -21,7 +21,6 @@
     PaymentParams,
     SendTransactionComposerResults,
     TransactionComposer,
-    TransactionComposerError,
     TransactionComposerParams,
 )
 
@@ -428,11 +427,10 @@ def transformer(error: Exception) -> Exception:
 def test_validation_occurs_on_send(algorand: AlgorandClient, funded_account: AddressWithSigners) -> None:
     params = AssetDestroyParams(asset_id=0, sender=funded_account.addr)
     with pytest.raises(
-        TransactionComposerError,
+        TransactionValidationError,
         match="Asset config validation failed: Total is required",
-    ) as ex:
+    ):
         algorand.send.asset_destroy(params)
-    assert isinstance(ex.value.__cause__, TransactionValidationError)
 
 
 def test_simulate_does_not_throw_when_disabled(algorand: AlgorandClient, funded_account: AddressWithSigners) -> None: