Improve Ethers.TxData module (#155)

* Export `TxData.to_map/2` function in docs

* Move abi_decode to TxData module

* Update CHANGELOG.md

CHANGELOG.md

@@ -1,5 +1,12 @@
 # Changelog
 
+## Unreleased
+
+### Enhancements
+
+- Move and export abi decode functionality to `Ethers.TxData` module
+- Export `Ethers.TxData.to_map/2` in docs
+
 ## v0.5.4 (2024-10-22)
 
 ### Bug fixes

lib/ethers.ex

@@ -661,14 +661,10 @@ defmodule Ethers do
 
   defp pre_process(data, [], _action, _opts), do: {:ok, data}
 
-  defp post_process({:ok, resp}, %{selector: selector}, :call) when valid_result(resp) do
-    selector
-    |> ABI.decode(Ethers.Utils.hex_decode!(resp), :output)
-    |> Enum.zip(selector.returns)
-    |> Enum.map(fn {return, type} -> Utils.human_arg(return, type) end)
-    |> case do
-      [element] -> {:ok, element}
-      elements -> {:ok, elements}
+  defp post_process({:ok, resp}, %{selector: _selector} = tx_data, :call)
+       when valid_result(resp) do
+    with {:ok, data} <- Utils.hex_decode(resp) do
+      TxData.abi_decode(data, tx_data, :output)
     end
   end
 

lib/ethers/tx_data.ex

@@ -4,6 +4,8 @@ defmodule Ethers.TxData do
   and the target `to` address.
   """
 
+  alias Ethers.Utils
+
   @typedoc """
   Holds transaction data, the function selector and the default `to` address.
 
@@ -31,8 +33,12 @@ defmodule Ethers.TxData do
     }
   end
 
-  @doc false
+  @doc """
+  Converts a TxData struct and optional overrides to a map ready for RPC data.
+  """
   @spec to_map(t() | map(), Keyword.t()) :: map()
+  def to_map(tx_data, overrides \\ [])
+
   def to_map(%__MODULE__{} = tx_data, overrides) do
     tx_data
     |> get_tx_map()
@@ -48,6 +54,33 @@ defmodule Ethers.TxData do
     end)
   end
 
+  @doc """
+  ABI decodes a function input/output given a TxData or FunctionSelector
+  """
+  @spec abi_decode(binary(), ABI.FunctionSelector.t() | t(), type :: :input | :output) ::
+          {:ok, any() | [any()]}
+  def abi_decode(data, tx_data_or_selector, type \\ :output)
+
+  def abi_decode(data, %{selector: %ABI.FunctionSelector{} = selector}, type),
+    do: abi_decode(data, selector, type)
+
+  def abi_decode(data, %ABI.FunctionSelector{} = selector, type) do
+    types =
+      case type do
+        :input -> selector.types
+        :output -> selector.returns
+      end
+
+    selector
+    |> ABI.decode(data, type)
+    |> Enum.zip(types)
+    |> Enum.map(fn {return, type} -> Utils.human_arg(return, type) end)
+    |> case do
+      [element] -> {:ok, element}
+      elements -> {:ok, elements}
+    end
+  end
+
   defp get_tx_map(%{selector: %{type: :function}} = tx_data) do
     %{data: tx_data.data}
     |> maybe_add_to_address(tx_data.default_address)