Unify testing of evaluator related functionality

Signed-off-by: José Valim <jose.valim@plataformatec.com.br>

Author: José Valim

lib/iex/lib/iex/autocomplete.ex

@@ -185,7 +185,7 @@ defmodule IEx.Autocomplete do
 
   defp expand_alias([name | rest] = list, server) do
     module = Module.concat(Elixir, name)
-    Enum.find_value env_aliases(server), list, fn {alias, mod} ->
+    Enum.find_value aliases_from_env(server), list, fn {alias, mod} ->
       if alias === module do
         case Atom.to_string(mod) do
           "Elixir." <> mod ->
@@ -197,12 +197,8 @@ defmodule IEx.Autocomplete do
     end
   end
 
-  defp env_aliases(server), do: server.current_env.aliases
-
-  defp get_evaluator(server), do: server.evaluator
-
   defp match_aliases(hint, server) do
-    for {alias, _mod} <- env_aliases(server),
+    for {alias, _mod} <- aliases_from_env(server),
         [name] = Module.split(alias),
         starts_with?(name, hint) do
       %{kind: :module, type: :alias, name: name}
@@ -386,8 +382,17 @@ defmodule IEx.Autocomplete do
     :binary.part(name, hint_size, byte_size(name) - hint_size)
   end
 
+  defp aliases_from_env(server) do
+    with evaluator when is_pid(evaluator) <- server.evaluator,
+         {:ok, aliases} <- IEx.Evaluator.value_from_env(evaluator, :aliases) do
+      aliases
+    else
+      _ -> []
+    end
+  end
+
   defp value_from_binding(ast_node, server) do
-    with evaluator when is_pid(evaluator) <- get_evaluator(server),
+    with evaluator when is_pid(evaluator) <- server.evaluator(),
          {var, map_key_path} <- extract_from_ast(ast_node, []) do
       IEx.Evaluator.value_from_binding(evaluator, var, map_key_path)
     else

lib/iex/lib/iex/evaluator.ex

@@ -40,14 +40,29 @@ defmodule IEx.Evaluator do
     end
   end
 
+  @doc """
+  Returns the current session environment if a session exists.
+  """
+  @spec value_from_env(pid, atom) :: {:ok, term} | :error
+  def value_from_env(evaluator, key) do
+    ref = make_ref()
+    send evaluator, {:value_from_env, ref, self(), key}
+
+    receive do
+      {^ref, result} -> result
+    after
+      5000 -> :error
+    end
+  end
+
   defp loop(server, history, state) do
     receive do
       {:eval, ^server, code, iex_state} ->
         {result, history, state} = eval(code, iex_state, history, state)
         send server, {:evaled, self(), result}
         loop(server, history, state)
-      {:peek_env, receiver} ->
-        send receiver, {:peek_env, state.env}
+      {:value_from_env, ref, receiver, key} ->
+        send receiver, {ref, Map.fetch(state.env, key)}
         loop(server, history, state)
       {:value_from_binding, ref, receiver, var_name, map_key_path} ->
         value = traverse_binding(state.binding, var_name, map_key_path)

lib/iex/lib/iex/server.ex

@@ -55,23 +55,6 @@ defmodule IEx.Server do
     end
   end
 
-  @doc """
-  Returns the current session environment if a session exists.
-  """
-  @spec current_env :: Macro.Env.t
-  def current_env() do
-    case IEx.Server.whereis() do
-      nil -> %Macro.Env{}
-      server ->
-        send(server, {:peek_env, self()})
-        receive do
-          {:peek_env, %Macro.Env{} = env} -> env
-        after
-          5000 -> %Macro.Env{}
-        end
-    end
-  end
-
   @doc """
   Requests to take over the given shell from the
   current process.
@@ -209,9 +192,6 @@ defmodule IEx.Server do
         exit_loop(evaluator, evaluator_ref)
       {:input, ^input, {:error, :terminated}} ->
         exit_loop(evaluator, evaluator_ref)
-      {:peek_env, receiver} ->
-        send evaluator, {:peek_env, receiver}
-        wait_input(state, evaluator, evaluator_ref, input)
       msg ->
         handle_take_over(msg, evaluator, evaluator_ref, input, fn ->
           wait_input(state, evaluator, evaluator_ref, input)

lib/iex/test/iex/autocomplete_test.exs

@@ -18,8 +18,14 @@ defmodule IEx.AutocompleteTest do
     :ok
   end
 
+  defmodule MyServer do
+    def evaluator do
+      Process.get(:evaluator)
+    end
+  end
+
   def expand(expr) do
-    IEx.Autocomplete.expand(Enum.reverse(expr), __MODULE__.MyServer)
+    IEx.Autocomplete.expand(Enum.reverse(expr), MyServer)
   end
 
   test "Erlang module completion" do
@@ -207,22 +213,14 @@ defmodule IEx.AutocompleteTest do
     assert expand('IEx.AutocompleteTest.SublevelTest.') == {:yes, 'LevelA', []}
   end
 
-  defmodule MyServer do
-    def current_env do
-      %Macro.Env{aliases: [{MyList, List}, {EList, :lists}]}
-    end
-
-    def evaluator do
-      Process.get(:evaluator)
-    end
-  end
-
+  @tag previous_line: "alias List, as: MyList"
   test "complete aliases of Elixir modules" do
     assert expand('MyL') == {:yes, 'ist', []}
     assert expand('MyList') == {:yes, '.', []}
     assert expand('MyList.to_integer') == {:yes, [], ['to_integer/1', 'to_integer/2']}
   end
 
+  @tag previous_line: "alias :lists, as: EList"
   test "complete aliases of Erlang modules" do
     assert expand('EL') == {:yes, 'ist', []}
     assert expand('EList') == {:yes, '.', []}