From 1bd3715877513b6d351a27d36a86abb20470decf Mon Sep 17 00:00:00 2001
From: Lukasz Samson <lukaszsamson@gmail.com>
Date: Fri, 27 Sep 2024 22:18:04 +0200
Subject: [PATCH] address todos

---
 lib/elixir_sense/core/compiler.ex                    | 12 ++++++++++--
 .../core/metadata_builder/error_recovery_test.exs    |  9 +++++++++
 test/elixir_sense/core/metadata_builder_test.exs     |  4 +---
 3 files changed, 20 insertions(+), 5 deletions(-)

diff --git a/lib/elixir_sense/core/compiler.ex b/lib/elixir_sense/core/compiler.ex
index 90ee028e..1beb5299 100644
--- a/lib/elixir_sense/core/compiler.ex
+++ b/lib/elixir_sense/core/compiler.ex
@@ -1454,7 +1454,6 @@ defmodule ElixirSense.Core.Compiler do
           raise ArgumentError, "defimpl/3 expects a :for option when declared outside a module"
       end)
 
-    # TODO how to look for cursor in for?
     for =
       __MODULE__.Macro.expand_literals(for, %{
         env
@@ -1462,6 +1461,14 @@ defmodule ElixirSense.Core.Compiler do
           function: {:__impl__, 1}
       })
 
+    {for, state} =
+      if is_atom(for) do
+        {for, state}
+      else
+        {_, state, _} = expand(for, state, env)
+        {:"Elixir.__UNKNOWN__", state}
+      end
+
     {protocol, state, _env} = expand(name, state, env)
 
     impl = fn protocol, for, block, state, env ->
@@ -1481,7 +1488,8 @@ defmodule ElixirSense.Core.Compiler do
     block =
       case opts do
         [] ->
-          raise ArgumentError, "defimpl expects a do-end block"
+          # elixir raises here
+          nil
 
         [do: block] ->
           block
diff --git a/test/elixir_sense/core/metadata_builder/error_recovery_test.exs b/test/elixir_sense/core/metadata_builder/error_recovery_test.exs
index a2b6e562..fe485472 100644
--- a/test/elixir_sense/core/metadata_builder/error_recovery_test.exs
+++ b/test/elixir_sense/core/metadata_builder/error_recovery_test.exs
@@ -2807,4 +2807,13 @@ defmodule ElixirSense.Core.MetadataBuilder.ErrorRecoveryTest do
       assert env.module == Abc
     end
   end
+
+  test "defimpl for" do
+    code = """
+    defimpl Enumerable, for: \
+    """
+
+    assert {_, env} = get_cursor_env(code)
+    assert env.module == nil
+  end
 end
diff --git a/test/elixir_sense/core/metadata_builder_test.exs b/test/elixir_sense/core/metadata_builder_test.exs
index 2a90604d..4dbcdec2 100644
--- a/test/elixir_sense/core/metadata_builder_test.exs
+++ b/test/elixir_sense/core/metadata_builder_test.exs
@@ -999,7 +999,6 @@ defmodule ElixirSense.Core.MetadataBuilderTest do
 
       assert Map.keys(state.lines_to_env[9].versioned_vars) == [{:k, nil}, {:kv, nil}, {:v, nil}]
 
-      # TODO should we handle unquote_slicing in arg list?
       # TODO defquard on 1.18
       assert [
                %VarInfo{name: :k, positions: [{3, 21}, {4, 19}, {5, 19}, {6, 25}, {7, 17}]},
@@ -1009,7 +1008,6 @@ defmodule ElixirSense.Core.MetadataBuilderTest do
 
       assert Map.keys(state.lines_to_env[18].versioned_vars) == [keys: nil, kv: nil]
 
-      # TODO should we handle unquote_slicing in arg list?
       # TODO defquard on 1.18
       assert [
                %VarInfo{
@@ -8034,7 +8032,7 @@ defmodule ElixirSense.Core.MetadataBuilderTest do
                  specs: ["@type __unknown__() :: 123"],
                  kind: :type,
                  positions: [{4, 5}],
-                 end_positions: [{4, 30}],
+                 end_positions: [_],
                  generated: [false],
                  doc: "",
                  meta: %{hidden: true}