Support setopts request with binary option in IO proxy (#2983)

lib/livebook/runtime/evaluator/io_proxy.ex

@@ -228,12 +228,11 @@ defmodule Livebook.Runtime.Evaluator.IOProxy do
     {{:error, :enotsup}, state}
   end
 
-  defp io_request({:setopts, [encoding: encoding]}, state) when encoding in [:latin1, :unicode] do
-    {:ok, %{state | encoding: encoding}}
-  end
-
-  defp io_request({:setopts, _opts}, state) do
-    {{:error, :enotsup}, state}
+  defp io_request({:setopts, opts}, state) do
+    case setopts(opts, state) do
+      {:ok, state} -> {:ok, state}
+      :error -> {{:error, :enotsup}, state}
+    end
   end
 
   defp io_request(:getopts, state) do
@@ -465,6 +464,17 @@ defmodule Livebook.Runtime.Evaluator.IOProxy do
     ArgumentError -> {{:error, req}, state}
   end
 
+  defp setopts([{:encoding, encoding} | opts], state) when encoding in [:latin1, :unicode] do
+    setopts(opts, %{state | encoding: encoding})
+  end
+
+  defp setopts([opt | opts], state) when opt in [:binary, {:binary, true}] do
+    setopts(opts, state)
+  end
+
+  defp setopts([], state), do: {:ok, state}
+  defp setopts(_opts, _state), do: :error
+
   defp request_input_value(input_id, state) do
     request = {:runtime_evaluation_input_request, state.ref, self(), input_id}
     reply_tag = :runtime_evaluation_input_reply

test/livebook/runtime/evaluator/io_proxy_test.exs

@@ -44,6 +44,12 @@ defmodule Livebook.Runtime.Evaluator.IOProxyTest do
     test "IO.gets", %{io: io} do
       assert IO.gets(io, "name: ") == {:error, :enotsup}
     end
+
+    test ":io.setopts", %{io: io} do
+      assert :ok = :io.setopts(io, encoding: :unicode)
+      assert :ok = :io.setopts(io, [:binary])
+      assert {:error, :enotsup} = :io.setopts(io, [:unknown_option])
+    end
   end
 
   describe "input" do