Add analysis for Leap

config/config.exs

@@ -86,6 +86,9 @@ config :elixir_analyzer,
     "accumulate" => %{
       analyzer_module: ElixirAnalyzer.TestSuite.Accumulate
     },
+    "leap" => %{
+      analyzer_module: ElixirAnalyzer.TestSuite.Leap
+    },
     "list-ops" => %{
       analyzer_module: ElixirAnalyzer.TestSuite.ListOps
     },

lib/elixir_analyzer/constants.ex

@@ -69,6 +69,9 @@ defmodule ElixirAnalyzer.Constants do
     # Lasagna Comments
     lasagna_function_reuse: "elixir.lasagna.function_reuse",
 
+    # Leap Comments
+    leap_erlang_calendar: "elixir.leap.erlang_calendar",
+
     # Log Level Comments
     log_level_use_cond: "elixir.log-level.use_cond",
 

lib/elixir_analyzer/test_suite/leap.ex

@@ -0,0 +1,13 @@
+defmodule ElixirAnalyzer.TestSuite.Leap do
+  @moduledoc """
+  This is an exercise analyzer extension module for the concept exercise Leap
+  """
+
+  use ElixirAnalyzer.ExerciseTest
+
+  assert_no_call "does not call any functions from :calendar Erlang module" do
+    type :essential
+    called_fn module: :calendar, name: :_
+    comment ElixirAnalyzer.Constants.leap_erlang_calendar()
+  end
+end

test/elixir_analyzer/test_suite/leap_test.exs

@@ -0,0 +1,43 @@
+defmodule ElixirAnalyzer.TestSuite.LeapTest do
+  use ElixirAnalyzer.ExerciseTestCase,
+    exercise_test_module: ElixirAnalyzer.TestSuite.Leap
+
+  test_exercise_analysis "example solution",
+    comments: [] do
+    defmodule Year do
+      def leap_year?(year) do
+        div4?(year) && div100?(year) == div400?(year)
+      end
+
+      defp divides?(dividend, divisor), do: rem(dividend, divisor) == 0
+      defp div4?(dividend), do: divides?(dividend, 4)
+      defp div100?(dividend), do: divides?(dividend, 100)
+      defp div400?(dividend), do: divides?(dividend, 400)
+    end
+  end
+
+  test_exercise_analysis "forbids usage of :calendar Erlang module",
+    comments_include: [Constants.leap_erlang_calendar()] do
+    [
+      defmodule Year do
+        def leap_year?(year) do
+          :calendar.is_leap_year(year)
+        end
+      end,
+      defmodule Year do
+        import :calendar
+
+        def leap_year?(year) do
+          is_leap_year(year)
+        end
+      end,
+      defmodule Year do
+        alias :calendar, as: C
+
+        def leap_year?(year) do
+          C.is_leap_year(year)
+        end
+      end
+    ]
+  end
+end