Completion adjustments (#740)

* Show exceptions at the end of completion list

* Don't complete hidden functions

lib/livebook/intellisense.ex

@@ -118,6 +118,12 @@ defmodule Livebook.Intellisense do
   end
 
   defp include_in_completion?({:module, _module, _display_name, :hidden}), do: false
+
+  defp include_in_completion?(
+         {:function, _module, _name, _arity, _display_name, :hidden, _signatures, _specs}
+       ),
+       do: false
+
   defp include_in_completion?(_), do: true
 
   defp format_completion_item({:variable, name, value}),
@@ -201,12 +207,16 @@ defmodule Livebook.Intellisense do
       insert_text: name
     }
 
+  @ordered_kinds [:field, :variable, :module, :struct, :interface, :function, :type]
+
+  defp completion_item_priority(%{kind: :struct, detail: "exception"} = completion_item) do
+    {length(@ordered_kinds), completion_item.label}
+  end
+
   defp completion_item_priority(completion_item) do
     {completion_item_kind_priority(completion_item.kind), completion_item.label}
   end
 
-  @ordered_kinds [:field, :variable, :module, :struct, :interface, :function, :type]
-
   defp completion_item_kind_priority(kind) when kind in @ordered_kinds do
     Enum.find_index(@ordered_kinds, &(&1 == kind))
   end

test/livebook/intellisense_test.exs

@@ -273,13 +273,6 @@ defmodule Livebook.IntellisenseTest do
       {binding, env} = eval(do: nil)
 
       assert [
-               %{
-                 detail: "Livebook.TestModules.Hidden.hidden()",
-                 documentation: "This is a private API",
-                 insert_text: "hidden()",
-                 kind: :function,
-                 label: "hidden/0"
-               },
                %{
                  detail: "Livebook.TestModules.Hidden.visible()",
                  documentation: "No documentation available",
@@ -287,12 +280,7 @@ defmodule Livebook.IntellisenseTest do
                  kind: :function,
                  label: "visible/0"
                }
-             ] =
+             ] = Intellisense.get_completion_items("Livebook.TestModules.Hidden.", binding, env)
-               Intellisense.get_completion_items(
-                 "Livebook.TestModules.Hidden.",
-                 binding,
-                 env
-               )
     end
 
     test "Elixir root submodule completion" do