Improve UX when completing struct

apps/remote_control/test/fixtures/project/lib/structs.ex

@@ -17,6 +17,23 @@ defmodule Project.Structs do
           }
   end
 
+  defmodule Order do
+    @type t :: %__MODULE__{
+            id: integer(),
+            lines: [Line.t()]
+          }
+    defstruct [:id, :lines]
+
+    defmodule Line do
+      @type t :: %__MODULE__{
+              id: integer(),
+              product_id: integer(),
+              quantity: integer()
+            }
+      defstruct [:id, :product_id, :quantity]
+    end
+  end
+
   defmodule NotAStruct do
   end
 end

apps/server/lib/lexical/server/code_intelligence/completion/translations/module_or_behaviour.ex

@@ -24,15 +24,28 @@ defmodule Lexical.Server.CodeIntelligence.Completion.Translations.ModuleOrBehavi
 
     defines_struct? = Intelligence.defines_struct?(env.project, module.full_name)
 
+    immediate_descendent_structs =
+      immediate_descendent_struct_modules(env.project, module.full_name)
+
+    defines_struct_in_descendents? =
+      immediate_descendent_defines_struct?(env.project, module.full_name) and
+        length(immediate_descendent_structs) > 1
+
     cond do
+      struct_reference? and defines_struct_in_descendents? and defines_struct? ->
+        more = length(immediate_descendent_structs) - 1
+
+        [
+          Translations.Struct.completion(env, builder, module.name, module.full_name, more),
+          Translations.Struct.completion(env, builder, module.name, module.full_name)
+        ]
+
       struct_reference? and defines_struct? ->
         Translations.Struct.completion(env, builder, module.name, module.full_name)
 
       struct_reference? and
-          immediate_descentent_defines_struct?(env.project, module.full_name) ->
-        env.project
-        |> immediate_descendent_struct_modules(module.full_name)
-        |> Enum.map(fn child_module_name ->
+          immediate_descendent_defines_struct?(env.project, module.full_name) ->
+        Enum.map(immediate_descendent_structs, fn child_module_name ->
           local_name = local_module_name(module.full_name, child_module_name)
           Translations.Struct.completion(env, builder, local_name, child_module_name)
         end)
@@ -67,7 +80,7 @@ defmodule Lexical.Server.CodeIntelligence.Completion.Translations.ModuleOrBehavi
   defp strip_leading_period(<<".", rest::binary>>), do: rest
   defp strip_leading_period(string_without_period), do: string_without_period
 
-  defp immediate_descentent_defines_struct?(%Lexical.Project{} = project, module_name) do
+  defp immediate_descendent_defines_struct?(%Lexical.Project{} = project, module_name) do
     Intelligence.defines_struct?(project, module_name, to: :grandchild)
   end
 

apps/server/lib/lexical/server/code_intelligence/completion/translations/struct.ex

@@ -5,7 +5,6 @@ defmodule Lexical.Server.CodeIntelligence.Completion.Translations.Struct do
   alias Lexical.Server.CodeIntelligence.Completion.Translations
 
   use Translatable.Impl, for: Result.Struct
-  require Logger
 
   def translate(%Result.Struct{} = struct, builder, %Env{} = env) do
     if Env.in_context?(env, :struct_reference) do
@@ -20,6 +19,19 @@ defmodule Lexical.Server.CodeIntelligence.Completion.Translations.Struct do
     end
   end
 
+  def completion(%Env{} = env, builder, module_name, full_name, more) when is_integer(more) do
+    builder_opts = [
+      kind: :module,
+      label: "#{module_name}...(#{more} more structs)",
+      detail: "#{full_name}."
+    ]
+
+    insert_text = "#{module_name}."
+    range = edit_range(env)
+
+    builder.text_edit_snippet(env, insert_text, range, builder_opts)
+  end
+
   def completion(%Env{} = env, builder, struct_name, full_name) do
     builder_opts = [
       kind: :struct,

apps/server/test/lexical/server/code_intelligence/completion/translations/module_or_behaviour_test.exs

@@ -75,6 +75,25 @@ defmodule Lexical.Server.CodeIntelligence.Completion.Translations.ModuleOrBehavi
       assert apply_completion(completion) == "%MapSet{$1}\n"
     end
 
+    test "should work for aliased struct", %{project: project} do
+      source = ~q[
+        alias Project.Structs.Account, as: MyAccount
+        %My|
+      ]
+
+      expected = ~q[
+        alias Project.Structs.Account, as: MyAccount
+        %MyAccount{$1}
+      ]
+
+      assert {:ok, completion} =
+               project
+               |> complete(source)
+               |> fetch_completion(kind: :struct)
+
+      assert apply_completion(completion) == expected
+    end
+
     test "modules that define a struct should emit curlies if in a struct reference", %{
       project: project
     } do
@@ -182,9 +201,31 @@ defmodule Lexical.Server.CodeIntelligence.Completion.Translations.ModuleOrBehavi
 
     test "should offer no other types of completions", %{project: project} do
       assert [] = complete(project, "%MapSet.|")
-      assert [account, user] = complete(project, "%Project.|")
+      assert [account, order, order_line, user] = complete(project, "%Project.|")
+
       assert account.label == "Structs.Account"
+      assert order.label == "Structs.Order"
+      assert order_line.label == "Structs.Order.Line"
       assert user.label == "Structs.User"
     end
+
+    test "should offer two completions when there are struct and its descendants", %{
+      project: project
+    } do
+      source = ~q[
+        alias Project.Structs.Order
+        %O|
+      ]
+
+      [order_line, order] = complete(project, source)
+
+      assert order_line.label == "Order...(1 more structs)"
+      assert order_line.kind == :module
+      assert apply_completion(order_line) =~ "%Order."
+
+      assert order.label == "Order"
+      assert order.kind == :struct
+      assert apply_completion(order) =~ "%Order{$1}"
+    end
   end
 end

apps/server/test/lexical/server/code_intelligence/completion/translations/struct_test.exs

@@ -3,13 +3,13 @@ defmodule Lexical.Server.CodeIntelligence.Completion.Translations.StructTest do
 
   describe "structs" do
     test "should complete after %", %{project: project} do
-      assert {:ok, [_, _] = account_and_user} =
+      assert {:ok, [_, _, _] = account_and_user_and_order} =
                project
                |> complete("%Project.Structs.|")
                |> fetch_completion(kind: :struct)
 
-      assert Enum.find(account_and_user, &(&1.label == "User"))
-      account = Enum.find(account_and_user, &(&1.label == "Account"))
+      assert Enum.find(account_and_user_and_order, &(&1.label == "User"))
+      account = Enum.find(account_and_user_and_order, &(&1.label == "Account"))
       assert account
       assert account.detail == "Project.Structs.Account"
 
@@ -129,12 +129,18 @@ defmodule Lexical.Server.CodeIntelligence.Completion.Translations.StructTest do
     end
 
     test "when using %, child structs are returned", %{project: project} do
-      assert [account, user] = complete(project, "%Project.|", "%")
+      assert [account, order, order_line, user] = complete(project, "%Project.|", "%")
       assert account.label == "Structs.Account"
       assert account.detail == "Project.Structs.Account"
 
       assert user.label == "Structs.User"
       assert user.detail == "Project.Structs.User"
+
+      assert order.label == "Structs.Order"
+      assert order.detail == "Project.Structs.Order"
+
+      assert order_line.label == "Structs.Order.Line"
+      assert order_line.detail == "Project.Structs.Order.Line"
     end
 
     test "it should complete struct fields", %{project: project} do