Allow true to be used as an @impl value (#385)

Co-authored-by: Angelika Tyborska <angelikatyborska@fastmail.com>

Author: dabaer

elixir

@@ -42,6 +42,9 @@ defmodule ElixirAnalyzer.TestSuite.TakeANumberDeluxe do
         {:@, _, [{:impl, _, [{:__aliases__, _, [:GenServer]}]}]} ->
           %{acc | impl?: true}
 
+        {:@, _, [{:impl, _, [true]}]} ->
+          %{acc | impl?: true}
+
         {op, _, [{function_name, _, _} | _]} when op in @def_ops ->
           acc =
             cond do

lib/elixir_analyzer/test_suite/take_a_number_deluxe.ex

@@ -30,7 +30,7 @@ defmodule ElixirAnalyzer.ExerciseTest.FileSnifferTest do
           binary_type = type_from_binary(binary)
           extension_type = type_from_extension(extension)
 
-          if binary_type == extension_type do
+          if binary_type == extension_type and not is_nil(binary_type) do
             {:ok, binary_type}
           else
             {:error, "Warning, file format and file extension do not match."}

test/elixir_analyzer/test_suite/file_sniffer_test.exs

@@ -147,12 +147,36 @@ defmodule ElixirAnalyzer.TestSuite.TakeANumberDeluxeTest do
       end
     end
 
-    test_exercise_analysis "value must be a module",
+    test_exercise_analysis "module value not `GenServer`",
       comments_include: [Constants.take_a_number_deluxe_annotate_impl_genserver()] do
       defmodule TakeANumberDeluxe do
         use GenServer
 
-        @impl true
+        @impl NotGenServer
+        def init(init_arg) do
+          min_number = Keyword.get(init_arg, :min_number)
+          max_number = Keyword.get(init_arg, :max_number)
+          auto_shutdown_timeout = Keyword.get(init_arg, :auto_shutdown_timeout, :infinity)
+
+          case TakeANumberDeluxe.State.new(min_number, max_number, auto_shutdown_timeout) do
+            {:ok, state} -> {:ok, state, auto_shutdown_timeout}
+            {:error, error} -> {:stop, error}
+          end
+        end
+
+        @impl NotGenServer
+        def handle_call(:report_state, _from, state) do
+          {:reply, state, state, state.auto_shutdown_timeout}
+        end
+      end
+    end
+
+    test_exercise_analysis "boolean value not `true`",
+      comments_include: [Constants.take_a_number_deluxe_annotate_impl_genserver()] do
+      defmodule TakeANumberDeluxe do
+        use GenServer
+
+        @impl false
         def init(init_arg) do
           min_number = Keyword.get(init_arg, :min_number)
           max_number = Keyword.get(init_arg, :max_number)
@@ -164,7 +188,31 @@ defmodule ElixirAnalyzer.TestSuite.TakeANumberDeluxeTest do
           end
         end
 
+        @impl false
+        def handle_call(:report_state, _from, state) do
+          {:reply, state, state, state.auto_shutdown_timeout}
+        end
+      end
+    end
+
+    test_exercise_analysis "value can be `GenServer` or `true`",
+      comments_exclude: [Constants.take_a_number_deluxe_annotate_impl_genserver()] do
+      defmodule TakeANumberDeluxe do
+        use GenServer
+
         @impl true
+        def init(init_arg) do
+          min_number = Keyword.get(init_arg, :min_number)
+          max_number = Keyword.get(init_arg, :max_number)
+          auto_shutdown_timeout = Keyword.get(init_arg, :auto_shutdown_timeout, :infinity)
+
+          case TakeANumberDeluxe.State.new(min_number, max_number, auto_shutdown_timeout) do
+            {:ok, state} -> {:ok, state, auto_shutdown_timeout}
+            {:error, error} -> {:stop, error}
+          end
+        end
+
+        @impl GenServer
         def handle_call(:report_state, _from, state) do
           {:reply, state, state, state.auto_shutdown_timeout}
         end