Allow skipping checksum address in Utils.public_key_to_address (#116)

* Make it possible to opt-out of checksum address

* Update CHANGELOG.md

CHANGELOG.md

@@ -6,6 +6,7 @@
 
 - Add ERC-165 contract and behaviour
 - Add `skip_docs` option for contract module doc and typespec generation
+- Allow skipping checksum address in `Ethers.Utils.public_key_to_address/2`
 
 ## v0.4.3 (2024-04-05)
 

lib/ethers/utils.ex

@@ -246,6 +246,9 @@ defmodule Ethers.Utils do
   def to_checksum_address("0x" <> address), do: to_checksum_address(address)
   def to_checksum_address("0X" <> address), do: to_checksum_address(address)
 
+  def to_checksum_address(<<address_bin::binary-20>>),
+    do: hex_encode(address_bin) |> to_checksum_address()
+
   def to_checksum_address(address) do
     address = String.downcase(address)
 
@@ -295,33 +298,43 @@ defmodule Ethers.Utils do
       "0x90F8bf6A479f320ead074411a4B0e7944Ea8c9C1"
   """
   @spec public_key_to_address(Ethers.Types.t_pub_key()) :: Ethers.Types.t_address()
-  def public_key_to_address(<<public_key::binary-64>>) do
-    Ethers.keccak_module().hash_256(public_key)
-    |> :binary.part(32 - 20, 20)
-    |> hex_encode()
-    |> to_checksum_address()
+  def public_key_to_address(public_key, use_checksum_address \\ true)
+
+  def public_key_to_address(<<public_key::binary-64>>, use_checksum_address) do
+    address =
+      Ethers.keccak_module().hash_256(public_key)
+      |> :binary.part(32 - 20, 20)
+      |> hex_encode()
+
+    if use_checksum_address do
+      to_checksum_address(address)
+    else
+      address
+    end
   end
 
-  def public_key_to_address(<<4, public_key::binary-64>>) do
-    public_key_to_address(public_key)
+  def public_key_to_address(<<4, public_key::binary-64>>, use_checksum_address) do
+    public_key_to_address(public_key, use_checksum_address)
   end
 
   unless Code.ensure_loaded?(Ethers.secp256k1_module()) do
-    def public_key_to_address(<<pre, _::binary-32>> = compressed) when pre in [2, 3],
-      do: raise("secp256k1 module not loaded")
+    def public_key_to_address(<<pre, _::binary-32>> = compressed, _use_checksum_address)
+        when pre in [2, 3],
+        do: raise("secp256k1 module not loaded")
   end
 
-  def public_key_to_address(<<pre, _::binary-32>> = compressed) when pre in [2, 3] do
+  def public_key_to_address(<<pre, _::binary-32>> = compressed, use_checksum_address)
+      when pre in [2, 3] do
     case Ethers.secp256k1_module().public_key_decompress(compressed) do
-      {:ok, public_key} -> public_key_to_address(public_key)
+      {:ok, public_key} -> public_key_to_address(public_key, use_checksum_address)
       error -> raise ArgumentError, "Invalid compressed public key #{inspect(error)}"
     end
   end
 
-  def public_key_to_address("0x" <> _ = key) do
+  def public_key_to_address("0x" <> _ = key, use_checksum_address) do
     key
     |> hex_decode!()
-    |> public_key_to_address()
+    |> public_key_to_address(use_checksum_address)
   end
 
   @doc """

test/ethers/utils_test.exs

@@ -83,4 +83,39 @@ defmodule Ethers.UtilsTest do
                    fn -> Ethers.Utils.hex_decode!("0xrubbish") end
     end
   end
+
+  describe "to_checksum_address/1" do
+    test "converts address to checksum form" do
+      assert Ethers.Utils.to_checksum_address("0x90f8bf6a479f320ead074411a4b0e7944ea8c9c1") ==
+               "0x90F8bf6A479f320ead074411a4B0e7944Ea8c9C1"
+
+      assert Ethers.Utils.to_checksum_address("0x90F8BF6A479F320EAD074411A4B0E7944EA8C9C1") ==
+               "0x90F8bf6A479f320ead074411a4B0e7944Ea8c9C1"
+    end
+
+    test "works with binary addresses" do
+      bin_address = Ethers.Utils.hex_decode!("0x90f8bf6a479f320ead074411a4b0e7944ea8c9c1")
+
+      assert Ethers.Utils.to_checksum_address(bin_address) ==
+               "0x90F8bf6A479f320ead074411a4B0e7944Ea8c9C1"
+    end
+  end
+
+  describe "public_key_to_address/2" do
+    @public_key "0x04e68acfc0253a10620dff706b0a1b1f1f5833ea3beb3bde2250d5f271f3563606672ebc45e0b7ea2e816ecb70ca03137b1c9476eec63d4632e990020b7b6fba39"
+    test "converts public_key to address" do
+      assert Ethers.Utils.public_key_to_address(@public_key) ==
+               "0x90F8bf6A479f320ead074411a4B0e7944Ea8c9C1"
+
+      assert Ethers.Utils.public_key_to_address(@public_key, false) ==
+               "0x90f8bf6a479f320ead074411a4b0e7944ea8c9c1"
+    end
+
+    test "works with binary public_key" do
+      bin_public_key = Ethers.Utils.hex_decode!(@public_key)
+
+      assert Ethers.Utils.public_key_to_address(bin_public_key) ==
+               "0x90F8bf6A479f320ead074411a4B0e7944Ea8c9C1"
+    end
+  end
 end