fix(test-types): format Transaction values as readable hex-strings instead of raw bytes (#1803)

packages/testing/src/execution_testing/cli/gentest/source_code_generator.py

@@ -89,7 +89,6 @@ def format_code(code: str) -> str:
                 str(formatter_path),
                 "format",
                 str(input_file_path),
-                "--quiet",
                 "--no-cache",
                 "--config",
                 str(config_path),
@@ -100,7 +99,8 @@ def format_code(code: str) -> str:
         if result.returncode != 0:
             raise Exception(
                 f"Error formatting code using formatter '{formatter_path}': "
-                f"{result.stderr}"
+                f"returncode={result.returncode}, stdout={result.stdout!r}, "
+                f"stderr={result.stderr!r}"
             )
 
         # Return the formatted source code

packages/testing/src/execution_testing/test_types/transaction_types.py

@@ -3,6 +3,7 @@
 from dataclasses import dataclass
 from enum import IntEnum
 from functools import cached_property
+import numbers
 from typing import Any, ClassVar, Dict, Generic, List, Literal, Self, Sequence
 
 import ethereum_rlp as eth_rlp
@@ -842,6 +843,47 @@ def signer_minimum_balance(self, *, fork: Fork) -> int:
         else:
             return gas_price * gas_limit + self.value
 
+    def _format_field_value(self, value: Any) -> str:
+        """
+        Format a field value for string representation.
+
+        Uses decimal for numeric values (int, HexNumber, etc.) and
+        hex encoding for Address, Bytes, Hash, etc.
+        """
+        if value is None:
+            return "None"
+
+        # fields like 'value' should be shown as decimal number
+        if isinstance(value, numbers.Number):
+            # Force decimal representation for int subclasses like HexNumber
+            if isinstance(value, int):
+                return str(int(value))
+
+            return str(value)
+
+        # fields like 'to' should be shown as hex string
+        if hasattr(value, "hex") and callable(value.hex):
+            return f'"{value.hex()}"'
+
+        return repr(value)
+
+    def __repr__(self) -> str:
+        """
+        Return string representation with hex-encoded values for
+        applicable fields.
+        """
+        field_strs = []
+        for field_name in self.__class__.model_fields:
+            value = getattr(self, field_name)
+            formatted_value = self._format_field_value(value)
+            field_strs.append(f"{field_name}={formatted_value}")
+
+        return f"{self.__class__.__name__}({', '.join(field_strs)})"
+
+    def __str__(self) -> str:
+        """Return the repr string representation."""
+        return self.__repr__()
+
 
 class NetworkWrappedTransaction(CamelModel, RLPSerializable):
     """