fix crash in replace remote function code action when erlang module is aliased

handle aliased erlang modules

Author: lukaszsamson

apps/language_server/lib/language_server/providers/code_action/replace_remote_function.ex

@@ -13,6 +13,7 @@ defmodule ElixirLS.LanguageServer.Providers.CodeAction.ReplaceRemoteFunction do
   alias ElixirLS.LanguageServer.SourceFile
   alias ElixirSense.Core.Parser
   alias ElixirSense.Core.Metadata
+  alias ElixirSense.Core.Introspection
 
   import ElixirLS.LanguageServer.Providers.CodeAction.Helpers
 
@@ -157,17 +158,23 @@ defmodule ElixirLS.LanguageServer.Providers.CodeAction.ReplaceRemoteFunction do
 
   @spec expand_alias(SourceFile.t(), [atom()], non_neg_integer()) :: {:ok, atom()} | :error
   defp expand_alias(source_file, module_alias, line_number) do
-    # TODO use Macro.Env
     with {:ok, aliases} <- aliases_at(source_file, line_number) do
       aliases
       |> Enum.map(fn {module, aliased} ->
         module = module |> module_to_alias() |> List.first()
-        aliased = module_to_alias(aliased)
 
-        {module, aliased}
+        if Introspection.elixir_module?(aliased) do
+          aliased = module_to_alias(aliased)
+          {module, aliased}
+        else
+          {module, aliased}
+        end
       end)
       |> Enum.find(fn {module, _aliased} -> List.starts_with?(module_alias, [module]) end)
       |> case do
+        {_module, aliased} when is_atom(aliased) ->
+          {:ok, aliased}
+
         {_module, aliased} ->
           module_alias = aliased ++ Enum.drop(module_alias, 1)
 

apps/language_server/test/providers/code_action/replace_remote_function_test.exs

@@ -181,6 +181,23 @@ defmodule ElixirLS.LanguageServer.Providers.CodeAction.ReplaceRemoteFunctionTest
 
         assert result == ":ets.insert(a, b)"
       end
+
+      test "handles erlang functions aliased" do
+        message = """
+        :ets.inserd/2 is undefined or private. Did you mean:
+              * insert/2
+              * insert_new/2
+        """
+
+        {:ok, [result]} =
+          ~q{
+          alias :ets, as: Foo
+          Foo.inserd(a, b)
+        }
+          |> modify(message: message, suggestion: "Foo.insert(a, b)", line: 1)
+
+        assert result == "alias :ets, as: Foo\nFoo.insert(a, b)"
+      end
     end
 
     if Version.match?(System.version(), ">= 1.15.0") do
@@ -200,6 +217,25 @@ defmodule ElixirLS.LanguageServer.Providers.CodeAction.ReplaceRemoteFunctionTest
 
         assert result == "alias ElixirLS.Test.RemoteFunction\nRemoteFunction.foo(42)"
       end
+
+      test "when erlang module aliased" do
+        message = """
+        ElixirLS.Test.RemoteFunction.fou/1 is undefined or private. Did you mean:
+
+              * foo/1
+        """
+
+        {:ok, [result]} =
+          ~q{
+        alias :ets, as: Foo
+        alias ElixirLS.Test.RemoteFunction
+        RemoteFunction.fou(42)
+      }
+          |> modify(message: message, suggestion: "RemoteFunction.foo", line: 2)
+
+        assert result ==
+                 "alias :ets, as: Foo\nalias ElixirLS.Test.RemoteFunction\nRemoteFunction.foo(42)"
+      end
     end
 
     if Version.match?(System.version(), ">= 1.15.0") do