Unescape characters for string output type in the contract response

CHANGELOG.md

@@ -3,6 +3,7 @@
 ### Features
 
 ### Fixes
+- [#4453](https://github.com/blockscout/blockscout/pull/4453) - Unescape characters for string output type in the contract response
 - [#4401](https://github.com/blockscout/blockscout/pull/4401) - Fix displaying of token holders with the same amount
 
 ### Chore

apps/ethereum_jsonrpc/lib/ethereum_jsonrpc/encoder.ex

@@ -83,6 +83,7 @@ defmodule EthereumJSONRPC.Encoder do
       |> Enum.zip(types_list)
       |> Enum.map(fn
         {value, :address} -> "0x" <> Base.encode16(value, case: :lower)
+        {value, :string} -> unescape(value)
         {value, _} -> value
       end)
 
@@ -91,4 +92,15 @@ defmodule EthereumJSONRPC.Encoder do
     MatchError ->
       {id, {:error, :invalid_data}}
   end
+
+  def unescape(data) do
+    if String.starts_with?(data, "\\x") do
+      charlist = String.to_charlist(data)
+      erlang_literal = '"#{charlist}"'
+      {:ok, [{:string, _, unescaped_charlist}], _} = :erl_scan.string(erlang_literal)
+      List.to_string(unescaped_charlist)
+    else
+      data
+    end
+  end
 end

apps/explorer/lib/explorer/smart_contract/reader.ex

@@ -6,7 +6,7 @@ defmodule Explorer.SmartContract.Reader do
   [wiki](https://github.com/ethereum/wiki/wiki/Ethereum-Contract-ABI).
   """
 
-  alias EthereumJSONRPC.Contract
+  alias EthereumJSONRPC.{Contract, Encoder}
   alias Explorer.Chain
   alias Explorer.Chain.{Hash, SmartContract}
   alias Explorer.SmartContract.Helper
@@ -503,6 +503,14 @@ defmodule Explorer.SmartContract.Reader do
     Map.put_new(output, "value", bytes_to_string(Enum.at(values, index)))
   end
 
+  defp new_value(%{"type" => :string} = output, [value], _index) do
+    Map.put_new(output, "value", Encoder.unescape(value))
+  end
+
+  defp new_value(%{"type" => "string"} = output, [value], _index) do
+    Map.put_new(output, "value", Encoder.unescape(value))
+  end
+
   defp new_value(output, [value], _index) do
     Map.put_new(output, "value", value)
   end

bin/install_chrome_headless.sh

@@ -1,6 +1,7 @@
 export DISPLAY=:99.0
 sh -e /etc/init.d/xvfb start
-export CHROMEDRIVER_VERSION=`curl -s http://chromedriver.storage.googleapis.com/LATEST_RELEASE`
+# export CHROMEDRIVER_VERSION=`curl -s http://chromedriver.storage.googleapis.com/LATEST_RELEASE`
+export CHROMEDRIVER_VERSION=`92.0.4515.43`
 curl -L -O "http://chromedriver.storage.googleapis.com/${CHROMEDRIVER_VERSION}/chromedriver_linux64.zip"
 unzip chromedriver_linux64.zip
 sudo chmod +x chromedriver