Only add if_undefined: :apply if necessary

Author: josevalim

lib/elixir/lib/kernel/special_forms.ex

@@ -1320,7 +1320,7 @@ defmodule Kernel.SpecialForms do
   Which the argument for the `:sum` function call is not the
   expected result:
 
-      {:sum, [], [1, {:value, [if_undefined: :apply], Elixir}, 3]}
+      {:sum, [], [1, {:value, [], Elixir}, 3]}
 
   For this, we use `unquote`:
 

lib/elixir/lib/macro.ex

@@ -162,6 +162,8 @@ defmodule Macro do
     * `:generated` - Whether the code should be considered as generated by
       the compiler or not. This means the compiler and tools like Dialyzer may not
       emit certain warnings.
+    * `:if_undefined` - How to expand a variable that is undefined. Set it to
+      `:apply` if you want a variable to become a nullary call without warning.
     * `:keep` - Used by `quote/2` with the option `location: :keep` to annotate
       the file and the line number of the quoted source.
     * `:line` - The line number of the AST node.

lib/iex/lib/iex/evaluator.ex

@@ -324,8 +324,9 @@ defmodule IEx.Evaluator do
   end
 
   defp eval_and_inspect(forms, line, state) do
-    forms = add_if_undefined_apply_to_vars(forms)
-    {result, binding, env} = eval_expr_by_expr(forms, state.binding, state.env)
+    %{env: env, binding: binding} = state
+    forms = add_if_undefined_apply_to_vars(forms, env)
+    {result, binding, env} = eval_expr_by_expr(forms, binding, env)
 
     unless result == IEx.dont_display_result() do
       io_inspect(result)
@@ -335,10 +336,14 @@ defmodule IEx.Evaluator do
     %{state | env: env, binding: binding, history: history}
   end
 
-  defp add_if_undefined_apply_to_vars(forms) do
+  defp add_if_undefined_apply_to_vars(forms, env) do
     Macro.prewalk(forms, fn
       {var, meta, context} when is_atom(var) and is_atom(context) ->
-        {var, Keyword.put_new(meta, :if_undefined, :apply), context}
+        if Macro.Env.lookup_import(env, {var, 0}) != [] do
+          {var, Keyword.put_new(meta, :if_undefined, :apply), context}
+        else
+          {var, meta, context}
+        end
 
       other ->
         other

lib/iex/test/iex/interaction_test.exs

@@ -198,8 +198,10 @@ defmodule IEx.InteractionTest do
 
   describe ".iex" do
     test "no .iex" do
-      assert "** (CompileError) iex:1: undefined function my_variable/0" <> _ =
-               capture_iex("my_variable")
+      capture_io(:stderr, fn ->
+        assert "** (CompileError) iex:1: undefined function my_variable/0" <> _ =
+                 capture_iex("my_variable")
+      end)
     end
 
     @tag :tmp_dir

lib/iex/test/iex/server_test.exs

@@ -42,12 +42,14 @@ defmodule IEx.ServerTest do
     test "outside of the evaluator with refusal", config do
       Process.register(self(), config.test)
 
-      {server, evaluator} = pry_session(config.test, "N\niex_context")
-      client = pry_request([server])
-      send(evaluator, :run)
+      capture_io(:stderr, fn ->
+        {server, evaluator} = pry_session(config.test, "N\niex_context")
+        client = pry_request([server])
+        send(evaluator, :run)
 
-      assert Task.await(client) == {:error, :refused}
-      assert Task.await(server) =~ "undefined function iex_context"
+        assert Task.await(client) == {:error, :refused}
+        assert Task.await(server) =~ "undefined function iex_context"
+      end)
     end
 
     test "outside of the evaluator with crash", config do
@@ -63,71 +65,79 @@ defmodule IEx.ServerTest do
     test "outside of the evaluator with double acceptance", config do
       Process.register(self(), config.test)
 
-      {server1, evaluator1} = pry_session(config.test, "Y\niex_context")
-      {server2, evaluator2} = pry_session(config.test, "Y\niex_context")
-      client = pry_request([server1, server2])
+      capture_io(:stderr, fn ->
+        {server1, evaluator1} = pry_session(config.test, "Y\niex_context")
+        {server2, evaluator2} = pry_session(config.test, "Y\niex_context")
+        client = pry_request([server1, server2])
 
-      send(evaluator1, :run)
-      send(evaluator2, :run)
-      reply1 = Task.await(server1)
-      reply2 = Task.await(server2)
+        send(evaluator1, :run)
+        send(evaluator2, :run)
+        reply1 = Task.await(server1)
+        reply2 = Task.await(server2)
 
-      {accepted, refused} =
-        if reply1 =~ ":inside_pry", do: {reply1, reply2}, else: {reply2, reply1}
+        {accepted, refused} =
+          if reply1 =~ ":inside_pry", do: {reply1, reply2}, else: {reply2, reply1}
 
-      assert accepted =~ ":inside_pry"
-      assert refused =~ "** session was already accepted elsewhere"
-      assert refused =~ "undefined function iex_context"
+        assert accepted =~ ":inside_pry"
+        assert refused =~ "** session was already accepted elsewhere"
+        assert refused =~ "undefined function iex_context"
 
-      assert Task.await(client) == {:ok, false}
+        assert Task.await(client) == {:ok, false}
+      end)
     end
 
     test "outside of the evaluator with double refusal", config do
       Process.register(self(), config.test)
 
-      {server1, evaluator1} = pry_session(config.test, "N\niex_context")
-      {server2, evaluator2} = pry_session(config.test, "N\niex_context")
-      client = pry_request([server1, server2])
+      capture_io(:stderr, fn ->
+        {server1, evaluator1} = pry_session(config.test, "N\niex_context")
+        {server2, evaluator2} = pry_session(config.test, "N\niex_context")
+        client = pry_request([server1, server2])
 
-      send(evaluator1, :run)
-      send(evaluator2, :run)
-      reply1 = Task.await(server1)
-      reply2 = Task.await(server2)
+        send(evaluator1, :run)
+        send(evaluator2, :run)
+        reply1 = Task.await(server1)
+        reply2 = Task.await(server2)
 
-      assert reply1 =~ "undefined function iex_context"
-      assert reply2 =~ "undefined function iex_context"
+        assert reply1 =~ "undefined function iex_context"
+        assert reply2 =~ "undefined function iex_context"
 
-      assert Task.await(client) == {:error, :refused}
+        assert Task.await(client) == {:error, :refused}
+      end)
     end
 
     test "outside of the evaluator with acceptance and then refusal", config do
       Process.register(self(), config.test)
 
-      {server1, evaluator1} = pry_session(config.test, "Y\niex_context")
-      {server2, evaluator2} = pry_session(config.test, "N\niex_context")
-      client = pry_request([server1, server2])
+      capture_io(:stderr, fn ->
+        {server1, evaluator1} = pry_session(config.test, "Y\niex_context")
+        {server2, evaluator2} = pry_session(config.test, "N\niex_context")
+        client = pry_request([server1, server2])
 
-      send(evaluator1, :run)
-      send(evaluator2, :run)
-      assert Task.await(server1) =~ ":inside_pry"
-      assert Task.await(server2) =~ "undefined function iex_context"
+        send(evaluator1, :run)
+        send(evaluator2, :run)
+        assert Task.await(server1) =~ ":inside_pry"
+        assert Task.await(server2) =~ "undefined function iex_context"
 
-      assert Task.await(client) == {:ok, false}
+        assert Task.await(client) == {:ok, false}
+      end)
     end
 
     test "outside of the evaluator with refusal and then acceptance", config do
       Process.register(self(), config.test)
 
-      {server1, evaluator1} = pry_session(config.test, "N\niex_context")
-      {server2, evaluator2} = pry_session(config.test, "Y\niex_context")
-      client = pry_request([server1, server2])
+      capture_io(:stderr, fn ->
+        {server1, evaluator1} = pry_session(config.test, "N\niex_context")
+        {server2, evaluator2} = pry_session(config.test, "Y\niex_context")
+        client = pry_request([server1, server2])
 
-      send(evaluator1, :run)
-      send(evaluator2, :run)
-      assert Task.await(server1) =~ "undefined function iex_context"
-      assert Task.await(server2) =~ ":inside_pry"
+        send(evaluator1, :run)
+        send(evaluator2, :run)
+        assert Task.await(server1) =~ "undefined function iex_context"
+        assert Task.await(server2) =~ ":inside_pry"
 
-      assert Task.await(client) == {:ok, false}
+        assert Task.await(client) == {:ok, false}
+      end)
     end
 
     @tag :tmp_dir
@@ -136,14 +146,16 @@ defmodule IEx.ServerTest do
       path = Path.join(tmp_dir, "dot-iex")
       File.write!(path, "my_variable = 144")
 
-      {server, evaluator} = pry_session(config.test, "Y\nmy_variable", dot_iex_path: path)
-      client = pry_request([server])
-      send(evaluator, :run)
+      capture_io(:stderr, fn ->
+        {server, evaluator} = pry_session(config.test, "Y\nmy_variable", dot_iex_path: path)
+        client = pry_request([server])
+        send(evaluator, :run)
 
-      assert Task.await(server) =~
-               "** (UndefinedFunctionError) function :erl_eval.my_variable/0 is undefined or private"
+        assert Task.await(server) =~
+                 "** (UndefinedFunctionError) function :erl_eval.my_variable/0 is undefined or private"
 
-      assert Task.await(client) == {:ok, false}
+        assert Task.await(client) == {:ok, false}
+      end)
     end
 
     @tag :tmp_dir