ash/test/resource/calculations_test.exs

defmodule Ash.Test.Resource.CalculationsTest do
  @moduledoc false
  use ExUnit.Case, async: true

  alias Ash.Resource.Calculation
  alias Ash.Test.Support.PolicySimple.Api
  alias Ash.Test.Support.PolicySimple.Post

  defmacrop defposts(do: body) do
    quote do
      defmodule Post do
        @moduledoc false
        use Ash.Resource

        attributes do
          uuid_primary_key :id

          attribute :name, :string
          attribute :contents, :string
        end

        unquote(body)
      end
    end
  end

  describe "representation" do
    test "calculations are persisted on the resource properly" do
      defposts do
        calculations do
          calculate :name_and_contents, :string, concat([:name, :context])
          calculate(:another_cal_but_private, :string, concat([:name, :context]), private?: true)
        end
      end

      assert [
               %Calculation{
                 name: :name_and_contents,
                 calculation: {Calculation.Concat, [keys: [:name, :context], separator: ""]},
                 private?: false
               },
               %Calculation{
                 name: :another_cal_but_private,
                 calculation: {Calculation.Concat, [keys: [:name, :context], separator: ""]},
                 private?: true
               }
             ] = Ash.Resource.Info.calculations(Post)

      assert [%Calculation{name: :name_and_contents}] =
               Ash.Resource.Info.public_calculations(Post)

      assert %Calculation{name: :another_cal_but_private} =
               Ash.Resource.Info.calculation(Post, :another_cal_but_private)

      assert nil == Ash.Resource.Info.public_calculation(Post, :another_cal_but_private)

      assert nil == Ash.Resource.Info.calculation(Post, :totally_legit_calculation)
    end

    test "Calculation descriptions are allowed" do
      defposts do
        calculations do
          calculate(:name_and_contents, :string, concat([:name, :context]),
            description: "require one of name/contents"
          )
        end
      end

      assert [
               %Ash.Resource.Calculation{description: "require one of name/contents"}
             ] = Ash.Resource.Info.calculations(Post)
    end
  end

  describe "relationships" do
    test "calculations can access attributes of parent" do
      defmodule Post do
        @moduledoc false
        use Ash.Resource, data_layer: Ash.DataLayer.Ets

        attributes do
          uuid_primary_key :id

          attribute :name, :string
          attribute :contents, :string
        end

        actions do
          defaults [:read, :update, :destroy, :create]
        end
      end

      defmodule PostName do
        @moduledoc """
        Calculates the name of the post, from the child comment.
        """
        use Ash.Calculation

        @impl true
        def load(_query, _opts, _context), do: [:post]

        @impl true
        def calculate(records, _opts, _) do
          Enum.map(records, fn comment ->
            post = comment.post
            post.name
          end)
        end
      end

      defmodule Comment do
        @moduledoc false
        use Ash.Resource, data_layer: Ash.DataLayer.Ets

        attributes do
          uuid_primary_key :id

          attribute :post_id, :uuid do
            allow_nil?(false)
          end
        end

        actions do
          defaults [:read, :update, :destroy, :create]
        end

        relationships do
          belongs_to :post, Post
        end

        calculations do
          calculate(:post_name, :string, PostName)
        end
      end

      defmodule Registry do
        @moduledoc false
        use Ash.Registry

        entries do
          entry(Post)
          entry(Comment)
        end
      end

      defmodule MyApi do
        @moduledoc false
        use Ash.Api

        resources do
          registry Registry
        end
      end

      post =
        Post
        |> Ash.Changeset.for_create(:create, %{name: "Post 1", contents: "Contents 1"})
        |> MyApi.create!()

      comment =
        Comment
        |> Ash.Changeset.for_create(:create, %{post_id: post.id})
        |> MyApi.create!()

      # assert true == true
      comment_with_post_name = Api.load!(comment, :post_name)
      assert comment_with_post_name.post_name == post.name
    end

    test "calculations can access attributes of parent in multitenant context" do
      defmodule Post do
        @moduledoc false
        use Ash.Resource, data_layer: Ash.DataLayer.Ets

        multitenancy do
          strategy(:context)
        end

        attributes do
          uuid_primary_key :id

          attribute :name, :string
          attribute :contents, :string
        end

        actions do
          defaults [:read, :update, :destroy, :create]
        end
      end

      defmodule PostName do
        @moduledoc """
        Calculates the name of the post, from the child comment.
        """
        use Ash.Calculation

        @impl true
        def load(_query, _opts, _context), do: [:post]

        @impl true
        def calculate(records, _opts, _) do
          Enum.map(records, fn comment ->
            post = comment.post
            post.name
          end)
        end
      end

      defmodule Comment do
        @moduledoc false
        use Ash.Resource, data_layer: Ash.DataLayer.Ets

        multitenancy do
          strategy(:context)
        end

        attributes do
          uuid_primary_key :id

          attribute :post_id, :uuid do
            allow_nil?(false)
          end
        end

        actions do
          defaults [:read, :update, :destroy, :create]
        end

        relationships do
          belongs_to :post, Post
        end

        calculations do
          calculate(:post_name, :string, PostName)
        end
      end

      defmodule Registry do
        @moduledoc false
        use Ash.Registry

        entries do
          entry(Post)
          entry(Comment)
        end
      end

      defmodule MyApi do
        @moduledoc false
        use Ash.Api

        resources do
          registry Registry
        end
      end

      tenant_id = "tenant1"

      post =
        Post
        |> Ash.Changeset.for_create(:create, %{name: "Post 1", contents: "Contents 1"},
          tenant: tenant_id
        )
        |> MyApi.create!()

      comment =
        Comment
        |> Ash.Changeset.for_create(:create, %{post_id: post.id}, tenant: tenant_id)
        |> MyApi.create!()

      comment_with_post_name = Api.load!(comment, :post_name, tenant: tenant_id)
      assert comment_with_post_name.post_name == post.name
    end
  end
end