Add analyzer for community-garden (#411)

* Add analyzer for community-garden

* Update lib/elixir_analyzer/test_suite/community_garden.ex

Co-authored-by: Jie <[email protected]>

---------

Co-authored-by: Jie <[email protected]>

config/config.exs

@@ -42,6 +42,9 @@ config :elixir_analyzer,
     "chessboard" => %{
       analyzer_module: ElixirAnalyzer.TestSuite.Chessboard
     },
+    "community-garden" => %{
+      analyzer_module: ElixirAnalyzer.TestSuite.CommunityGarden
+    },
     "dancing-dots" => %{
       analyzer_module: ElixirAnalyzer.TestSuite.DancingDots
     },

lib/elixir_analyzer/constants.ex

@@ -78,6 +78,9 @@ defmodule ElixirAnalyzer.Constants do
     captains_log_use_rand_uniform: "elixir.captains-log.use_rand_uniform",
     captains_log_use_io_lib: "elixir.captains-log.use_io_lib",
 
+    # Community Garden Comments
+    community_garden_use_get_and_update: "elixir.community-garden.use_get_and_update",
+
     # Dancing Dots Comments
     dancing_dots_annotate_impl_animation: "elixir.dancing-dots.annotate_impl_animation",
     dancing_dots_do_not_reimplement_init: "elixir.dancing-dots.do_not_reimplement_init",

lib/elixir_analyzer/test_suite/community_garden.ex

@@ -0,0 +1,14 @@
+defmodule ElixirAnalyzer.TestSuite.CommunityGarden do
+  @moduledoc """
+  This is an exercise analyzer extension module for the concept exercise Community Garden
+  """
+  use ElixirAnalyzer.ExerciseTest
+  alias ElixirAnalyzer.Constants
+
+  assert_call "register uses Agent.get_and_update" do
+    type :essential
+    calling_fn module: CommunityGarden, name: :register
+    called_fn module: Agent, name: :get_and_update
+    comment Constants.community_garden_use_get_and_update()
+  end
+end

test/elixir_analyzer/test_suite/community_garden_test.exs

@@ -0,0 +1,143 @@
+defmodule ElixirAnalyzer.ExerciseTest.CommunityGardenTest do
+  use ElixirAnalyzer.ExerciseTestCase,
+    exercise_test_module: ElixirAnalyzer.TestSuite.CommunityGarden
+
+  alias ElixirAnalyzer.Constants
+
+  test_exercise_analysis "example solution",
+    comments: [Constants.solution_same_as_exemplar()] do
+    ~S"""
+      defmodule Plot do
+        @enforce_keys [:plot_id, :registered_to]
+        defstruct [:plot_id, :registered_to]
+      end
+
+      defmodule CommunityGarden do
+        def start(opts \\ []) do
+          Agent.start(fn -> %{registry: %{}, next_id: 1} end, opts)
+        end
+
+        def list_registrations(pid) do
+          Agent.get(pid, fn state ->
+            Map.values(state.registry)
+          end)
+        end
+
+        def register(pid, register_to) do
+          Agent.get_and_update(pid, fn %{registry: registry, next_id: next_id} = state ->
+            new_plot = %Plot{plot_id: next_id, registered_to: register_to}
+            updated = Map.put(registry, next_id, new_plot)
+            {new_plot, %{state | registry: updated, next_id: next_id + 1}}
+          end)
+        end
+
+        def release(pid, plot_id) do
+          Agent.update(pid, fn %{registry: registry} = state ->
+            updated = Map.delete(registry, plot_id)
+            %{state | registry: updated}
+          end)
+        end
+
+        def get_registration(pid, plot_id) do
+          registration =
+            Agent.get(pid, fn state ->
+              state.registry[plot_id]
+            end)
+
+          case registration do
+            nil -> {:not_found, "plot is unregistered"}
+            _ -> registration
+          end
+        end
+      end
+    """
+  end
+
+  test_exercise_analysis "other reasonable solutions",
+    comments: [] do
+    [
+      defmodule CommunityGarden do
+        def start() do
+          Agent.start(fn -> %{plots: [], id: 0} end)
+        end
+
+        def list_registrations(pid) do
+          Agent.get(pid, fn %{plots: plots} -> plots end)
+        end
+
+        def register(pid, register_to) do
+          Agent.get_and_update(pid, fn %{plots: plots, id: id} ->
+            id = id + 1
+
+            {%Plot{plot_id: id, registered_to: register_to},
+             %{plots: [%Plot{plot_id: id, registered_to: register_to} | plots], id: id}}
+          end)
+        end
+
+        def release(pid, plot_id) do
+          Agent.cast(pid, fn %{plots: plots} = n ->
+            plots = Enum.filter(plots, fn %{plot_id: x} -> x != plot_id end)
+            %{n | plots: plots}
+          end)
+        end
+
+        def get_registration(pid, plot_id) do
+          case Enum.find(list_registrations(pid), fn _ -> plot_id end) do
+            nil -> {:not_found, "plot is unregistered"}
+            n -> n
+          end
+        end
+      end,
+      defmodule CommunityGarden do
+        def start() do
+          Agent.start(fn -> %{plots: [], index: 0} end)
+        end
+
+        def list_registrations(pid) do
+          Agent.get(pid, fn %{plots: plots} -> plots end)
+        end
+
+        def register(pid, register_to) do
+          Agent.get_and_update(pid, fn %{plots: plots, index: index} ->
+            index = index + 1
+            plot = %Plot{plot_id: index, registered_to: register_to}
+            {plot, %{plots: [plot | plots], index: index}}
+          end)
+        end
+
+        def release(pid, plot_id) do
+          Agent.cast(pid, fn %{plots: plots} = status ->
+            plots = Enum.filter(plots, fn %{plot_id: p} -> p !== plot_id end)
+            %{status | plots: plots}
+          end)
+        end
+
+        def get_registration(pid, plot_id) do
+          Agent.get(pid, fn %{plots: plots} ->
+            plots
+            |> Enum.find(
+              {:not_found, "plot is unregistered"},
+              fn %{plot_id: p} -> p === plot_id end
+            )
+          end)
+        end
+      end
+    ]
+  end
+
+  test_exercise_analysis "expects register to use Agent.get_and_update",
+    comments_include: [Constants.community_garden_use_get_and_update()] do
+    defmodule CommunityGarden do
+      def register(pid, register_to) do
+        state = Agent.get(pid, fn state -> state end)
+        %{registry: registry, next_id: next_id} = state
+        new_plot = %Plot{plot_id: next_id, registered_to: register_to}
+        updated = Map.put(registry, next_id, new_plot)
+        state = %{state | registry: updated, next_id: next_id + 1}
+        Agent.update(pid, fn x -> state end)
+
+        new_plot
+      end
+    end
+  end
+end