handle local behaviours and protocols in returns reducer

lib/elixir_sense/providers/suggestion/reducers/returns.ex

@@ -40,17 +40,38 @@ defmodule ElixirSense.Providers.Suggestion.Reducers.Returns do
 
     callbacks =
       for mod <- behaviours,
-          protocol == nil or mod != elem(protocol, 0),
-          return <- Introspection.get_returns_from_callback(mod, fun, arity) do
-        format_return(return)
+          protocol == nil or mod != elem(protocol, 0) do
+        case specs[{mod, fun, arity}] do
+          nil ->
+            for return <- Introspection.get_returns_from_callback(mod, fun, arity) do
+              format_return(return)
+            end
+
+          %State.SpecInfo{specs: info_specs} ->
+            for spec <- info_specs,
+                {:ok, {:@, _, [{_, _, [quoted]}]}} = Code.string_to_quoted(spec),
+                return <- Introspection.get_returns_from_spec_ast(quoted) do
+              format_return(return)
+            end
+        end
       end
+      |> List.flatten()
 
-    # TODO metadata protocols and behaviours
     protocol_functions =
       case protocol do
         {proto, _implementations} ->
-          for return <- Introspection.get_returns_from_callback(proto, fun, arity) do
-            format_return(return)
+          case specs[{proto, fun, arity}] do
+            nil ->
+              for return <- Introspection.get_returns_from_callback(proto, fun, arity) do
+                format_return(return)
+              end
+
+            %State.SpecInfo{specs: info_specs} ->
+              for spec <- info_specs,
+                  {:ok, {:@, _, [{:callback, _, [quoted]}]}} <- [Code.string_to_quoted(spec)],
+                  return <- Introspection.get_returns_from_spec_ast(quoted) do
+                format_return(return)
+              end
           end
 
         nil ->

test/elixir_sense/suggestions_test.exs

@@ -849,7 +849,7 @@ defmodule ElixirSense.SuggestionsTest do
            ] = list
   end
 
-  test "lists function return values" do
+  test "lists callback return values" do
     buffer = """
     defmodule MyServer do
       use ElixirSenseExample.ExampleBehaviour
@@ -912,7 +912,7 @@ defmodule ElixirSense.SuggestionsTest do
            ] = list
   end
 
-  test "lists macro return values" do
+  test "lists macrocallback return values" do
     buffer = """
     defmodule MyServer do
       @behaviour ElixirSenseExample.BehaviourWithMacrocallback
@@ -937,6 +937,36 @@ defmodule ElixirSense.SuggestionsTest do
            ]
   end
 
+  test "lists metadata callback return values" do
+    buffer = """
+    defmodule MyBehaviour do
+      @callback required(term()) :: {:ok, term()} | :error
+    end
+
+    defmodule MyServer do
+      @behaviour MyBehaviour
+
+      def required(arg) do
+
+      end
+    end
+    """
+
+    list =
+      ElixirSense.suggestions(buffer, 9, 5)
+      |> Enum.filter(fn s -> s.type == :return end)
+
+    assert list == [
+             %{
+               description: "{:ok, term()}",
+               snippet: "{:ok, term()}",
+               spec: "{:ok, term()}",
+               type: :return
+             },
+             %{description: ":error", snippet: ":error", spec: ":error", type: :return}
+           ]
+  end
+
   test "lists protocol implementation return values" do
     buffer = """
     defimpl Enumerable, for: MyStruct do
@@ -966,6 +996,35 @@ defmodule ElixirSense.SuggestionsTest do
            ] == list
   end
 
+  test "lists metadata protocol implementation return values" do
+    buffer = """
+    defprotocol MyProto do
+      @spec count(t()) :: {:ok, term()} | :error
+      def count(t)
+    end
+
+    defimpl MyProto, for: MyStruct do
+      def count(t) do
+
+      end
+    end
+    """
+
+    list =
+      ElixirSense.suggestions(buffer, 8, 6)
+      |> Enum.filter(fn s -> s.type == :return end)
+
+    assert [
+             %{
+               description: "{:ok, term()}",
+               snippet: "{:ok, term()}",
+               spec: "{:ok, term()}",
+               type: :return
+             },
+             %{description: ":error", snippet: ":error", spec: ":error", type: :return}
+           ] == list
+  end
+
   test "lists function with spec return values" do
     buffer = """
     defmodule SomeModule do