From 2c4b3522db38024e91bba137ed2d7f798df61381 Mon Sep 17 00:00:00 2001
From: Lukasz Samson <lukaszsamson@gmail.com>
Date: Tue, 26 Sep 2023 08:22:43 +0200
Subject: [PATCH] don't stringify complex types when building parameter list

Fixes https://github.com/elixir-lsp/elixir_sense/issues/279
---
 lib/elixir_sense/core/introspection.ex        | 10 ++++-----
 lib/elixir_sense/core/type_info.ex            | 16 +++++++++-----
 .../providers/suggestion/complete.ex          |  1 -
 .../providers/suggestion/complete_test.exs    | 21 +++++++++++++++++--
 4 files changed, 35 insertions(+), 13 deletions(-)

diff --git a/lib/elixir_sense/core/introspection.ex b/lib/elixir_sense/core/introspection.ex
index 26731589..078f63df 100644
--- a/lib/elixir_sense/core/introspection.ex
+++ b/lib/elixir_sense/core/introspection.ex
@@ -406,7 +406,7 @@ defmodule ElixirSense.Core.Introspection do
 
     results =
       for {{_name, _arity}, [params | _]} = spec <- specs do
-        params = TypeInfo.extract_params(params) |> Enum.map(&Atom.to_string/1)
+        params = TypeInfo.extract_params(params)
 
         %{
           name: Atom.to_string(fun),
@@ -527,7 +527,7 @@ defmodule ElixirSense.Core.Introspection do
 
     results =
       for {{_name, arity}, [params | _]} <- specs do
-        fun_args_text = TypeInfo.extract_params(params) |> Enum.map_join(", ", &Atom.to_string/1)
+        fun_args_text = TypeInfo.extract_params(params) |> Enum.join(", ")
 
         %{
           module: mod,
@@ -1846,7 +1846,7 @@ defmodule ElixirSense.Core.Introspection do
             # we don't expect macros here
             case TypeInfo.get_callback(behaviour, f, arity) do
               {_, [params | _]} ->
-                TypeInfo.extract_params(params) |> Enum.map(&Atom.to_string/1)
+                TypeInfo.extract_params(params)
 
               _ ->
                 # provide dummy
@@ -1860,11 +1860,11 @@ defmodule ElixirSense.Core.Introspection do
 
       [{:attribute, _, :spec, {{^f, ^arity}, [params | _]}}] ->
         # erlang doc with signature meta - moduleless form
-        TypeInfo.extract_params(params) |> Enum.map(&Atom.to_string/1)
+        TypeInfo.extract_params(params)
 
       [{:attribute, _, :spec, {{^mod, ^f, ^arity}, [params | _]}}] ->
         # erlang doc with signature meta - form with module
-        TypeInfo.extract_params(params) |> Enum.map(&Atom.to_string/1)
+        TypeInfo.extract_params(params)
     end
   end
 end
diff --git a/lib/elixir_sense/core/type_info.ex b/lib/elixir_sense/core/type_info.ex
index ff897fad..d79204c7 100644
--- a/lib/elixir_sense/core/type_info.ex
+++ b/lib/elixir_sense/core/type_info.ex
@@ -685,17 +685,23 @@ defmodule ElixirSense.Core.TypeInfo do
   end
 
   def extract_params(type) do
-    case Typespec.spec_to_quoted(:dummy, type) do
+    quoted = Typespec.spec_to_quoted(:dummy, type)
+
+    case quoted do
       {:when, _, [{:"::", _, [{:dummy, _, args}, _res]}, _var_args]} -> args
       {:"::", _, [{:dummy, _, args}, _res]} -> args
     end
     |> Enum.map(fn arg ->
       case arg do
-        {:"::", _, [left, _right]} -> left
-        other -> other
+        {:"::", _, [{atom, _, _}, _right]} when is_atom(atom) -> to_string(atom)
+        {:|, _, [_left, _right]} -> "term"
+        [_ | _] -> "list"
+        {_, _} -> "tuple"
+        {:{}, _, _} -> "tuple"
+        %{} -> "map"
+        {atom, _, _} when is_atom(atom) -> to_string(atom)
+        _other -> "term"
       end
-      |> Macro.to_string()
-      |> String.to_atom()
     end)
   end
 
diff --git a/lib/elixir_sense/providers/suggestion/complete.ex b/lib/elixir_sense/providers/suggestion/complete.ex
index 5dc8f2dd..8483deaf 100644
--- a/lib/elixir_sense/providers/suggestion/complete.ex
+++ b/lib/elixir_sense/providers/suggestion/complete.ex
@@ -1125,7 +1125,6 @@ defmodule ElixirSense.Providers.Suggestion.Complete do
 
   defp format_params({{_name, _arity}, [params | _]}, _arity_1) do
     TypeInfo.extract_params(params)
-    |> Enum.map(&Atom.to_string/1)
   end
 
   defp format_params(nil, 0), do: []
diff --git a/test/elixir_sense/providers/suggestion/complete_test.exs b/test/elixir_sense/providers/suggestion/complete_test.exs
index 6d1424c3..d7e2c0d7 100644
--- a/test/elixir_sense/providers/suggestion/complete_test.exs
+++ b/test/elixir_sense/providers/suggestion/complete_test.exs
@@ -1943,7 +1943,7 @@ defmodule ElixirSense.Providers.Suggestion.CompleteTest do
                name: "or",
                spec: "@spec boolean() or boolean() :: boolean()",
                type: :function,
-               args: "boolean(), boolean()",
+               args: "boolean, boolean",
                origin: ":erlang",
                summary: ""
              },
@@ -1964,7 +1964,7 @@ defmodule ElixirSense.Providers.Suggestion.CompleteTest do
                name: "and",
                spec: "@spec boolean() and boolean() :: boolean()",
                type: :function,
-               args: "boolean(), boolean()",
+               args: "boolean, boolean",
                origin: ":erlang",
                summary: ""
              },
@@ -2020,6 +2020,23 @@ defmodule ElixirSense.Providers.Suggestion.CompleteTest do
     end
   end
 
+  test "provide doc and specs for erlang functions with args from typespec" do
+    assert [
+             %{
+               name: "handle_call",
+               args_list: ["call", "from", "state"]
+             },
+             %{
+               name: "handle_cast",
+               args_list: ["tuple", "state"]
+             },
+             %{
+               name: "handle_info",
+               args_list: ["term", "state"]
+             }
+           ] = expand(~c":pg.handle_")
+  end
+
   test "complete after ! operator" do
     assert [%{name: "is_binary"}] = expand(~c"!is_bina")
   end