Merge pull request #94 from elopio/issue/tuple

decode: collapse tuples

mev_inspect/decode.py

@@ -1,5 +1,7 @@
 from typing import Dict, Optional
 
+import eth_utils.abi
+
 from hexbytes import HexBytes
 from eth_abi import decode_abi
 from eth_abi.exceptions import InsufficientDataBytes, NonEmptyPaddingBytes
@@ -26,7 +28,12 @@ class ABIDecoder:
             return None
 
         names = [input.name for input in func.inputs]
-        types = [input.type for input in func.inputs]
+        types = [
+            input.type
+            if input.type != "tuple"
+            else eth_utils.abi.collapse_if_tuple(input.dict())
+            for input in func.inputs
+        ]
 
         try:
             decoded = decode_abi(types, params)

mev_inspect/schemas/abi.py

@@ -1,7 +1,8 @@
 from enum import Enum
-from typing import List, Union
+from typing import List, Optional, Union
 from typing_extensions import Literal
 
+import eth_utils.abi
 from hexbytes import HexBytes
 from pydantic import BaseModel
 from web3 import Web3
@@ -26,6 +27,10 @@ NON_FUNCTION_DESCRIPTION_TYPES = Union[
 class ABIDescriptionInput(BaseModel):
     name: str
     type: str
+    components: Optional[List["ABIDescriptionInput"]]
+
+
+ABIDescriptionInput.update_forward_refs()
 
 
 class ABIGenericDescription(BaseModel):
@@ -42,7 +47,12 @@ class ABIFunctionDescription(BaseModel):
         return Web3.sha3(text=signature)[0:4]
 
     def get_signature(self) -> str:
-        joined_input_types = ",".join(input.type for input in self.inputs)
+        joined_input_types = ",".join(
+            input.type
+            if input.type != "tuple"
+            else eth_utils.abi.collapse_if_tuple(input.dict())
+            for input in self.inputs
+        )
         return f"{self.name}({joined_input_types})"
 
 

tests/test_decode.py

@@ -0,0 +1,69 @@
+import pydantic
+
+from mev_inspect import decode
+from mev_inspect.schemas import abi
+
+
+def test_decode_function_with_simple_argument():
+    test_function_name = "testFunction"
+    test_parameter_name = "testParameter"
+    test_abi = pydantic.parse_obj_as(
+        abi.ABI,
+        [
+            {
+                "name": test_function_name,
+                "type": "function",
+                "inputs": [{"name": test_parameter_name, "type": "uint256"}],
+            }
+        ],
+    )
+    # 4byte signature of the test function.
+    # https://www.4byte.directory/signatures/?bytes4_signature=0x350c530b
+    test_function_selector = "350c530b"
+    test_function_argument = (
+        "0000000000000000000000000000000000000000000000000000000000000001"
+    )
+    abi_decoder = decode.ABIDecoder(test_abi)
+    call_data = abi_decoder.decode(
+        "0x" + test_function_selector + test_function_argument
+    )
+    assert call_data.function_name == test_function_name
+    assert call_data.function_signature == "testFunction(uint256)"
+    assert call_data.inputs == {test_parameter_name: 1}
+
+
+def test_decode_function_with_tuple_argument():
+    test_function_name = "testFunction"
+    test_tuple_name = "testTuple"
+    test_parameter_name = "testParameter"
+    test_abi = pydantic.parse_obj_as(
+        abi.ABI,
+        [
+            {
+                "name": test_function_name,
+                "type": "function",
+                "inputs": [
+                    {
+                        "name": test_tuple_name,
+                        "type": "tuple",
+                        "components": [
+                            {"name": test_parameter_name, "type": "uint256"}
+                        ],
+                    }
+                ],
+            }
+        ],
+    )
+    # 4byte signature of the test function.
+    # https://www.4byte.directory/signatures/?bytes4_signature=0x98568079
+    test_function_selector = "98568079"
+    test_function_argument = (
+        "0000000000000000000000000000000000000000000000000000000000000001"
+    )
+    abi_decoder = decode.ABIDecoder(test_abi)
+    call_data = abi_decoder.decode(
+        "0x" + test_function_selector + test_function_argument
+    )
+    assert call_data.function_name == test_function_name
+    assert call_data.function_signature == "testFunction((uint256))"
+    assert call_data.inputs == {test_tuple_name: (1,)}