feat: add identify_aggregate to command router (#133)

apps/one_piece_commanded/.formatter.exs

@@ -1,7 +1,8 @@
 locals_without_parens = [
   register_type: 2,
   import_type_provider: 1,
-  dispatch_transaction_script: 2
+  dispatch_transaction_script: 2,
+  identify_aggregate: 1
 ]
 
 [

apps/one_piece_commanded/lib/one_piece/commanded/aggregate.ex

@@ -28,6 +28,11 @@ defmodule OnePiece.Commanded.Aggregate do
 
   It adds an `apply/2` callback to the module as a fallback, return the aggregate as it is.
 
+  ### Options
+
+  - `:identifier` - The aggregate identifier key.
+  - `:stream_prefix` (optional) - The prefix to be used for the identity.
+
   ## Using
 
   - `OnePiece.Commanded.Entity`
@@ -49,12 +54,27 @@ defmodule OnePiece.Commanded.Aggregate do
         end
       end
   """
-  @spec __using__(opts :: []) :: any()
+  @spec __using__(
+          opts ::
+            OnePiece.Commanded.Entity.using_opts()
+            | [stream_prefix: String.t() | nil]
+        ) :: any()
   defmacro __using__(opts \\ []) do
+    {opts, entity_opts} = Keyword.split(opts, [:stream_prefix])
+    stream_prefix = Keyword.get(opts, :stream_prefix)
+
     quote do
-      use OnePiece.Commanded.Entity, unquote(opts)
+      use OnePiece.Commanded.Entity, unquote(entity_opts)
       @behaviour OnePiece.Commanded.Aggregate
       @before_compile OnePiece.Commanded.Aggregate
+
+      @doc """
+      Returns `#{inspect(unquote(stream_prefix))}` as the identity prefix.
+      """
+      @spec stream_prefix :: String.t() | nil
+      def stream_prefix do
+        unquote(stream_prefix)
+      end
     end
   end
 

apps/one_piece_commanded/lib/one_piece/commanded/command_router.ex

@@ -156,4 +156,38 @@ defmodule OnePiece.Commanded.CommandRouter do
       Commanded.Commands.Router.dispatch(unquote(command_module), unquote(opts))
     end
   end
+
+  @doc """
+  Identify a given aggregate.
+
+  ## Example
+      defmodule BankAccount do
+        use OnePiece.Commanded.Aggregate
+          identifier: :uuid,
+          stream_prefix: "bank-account-"
+
+        embedded_schema do
+          # ...
+        end
+      end
+
+      defmodule Router do
+        use OnePiece.Commanded.CommandRouter
+        identify_aggregate OpenBankAccount
+      end
+  """
+  defmacro identify_aggregate(aggregate_module) do
+    aggregate_module = Macro.expand(aggregate_module, __CALLER__)
+
+    Code.ensure_compiled!(aggregate_module)
+
+    opts = [
+      by: Kernel.apply(aggregate_module, :identifier, []),
+      prefix: Kernel.apply(aggregate_module, :stream_prefix, [])
+    ]
+
+    quote do
+      Commanded.Commands.Router.identify(unquote(aggregate_module), unquote(opts))
+    end
+  end
 end

apps/one_piece_commanded/lib/one_piece/commanded/entity.ex

@@ -20,6 +20,8 @@ defmodule OnePiece.Commanded.Entity do
   """
   @type identifier_opt :: atom() | {key_name :: atom(), type :: atom()} | {key_name :: atom(), type :: module()}
 
+  @type using_opts :: [identifier: identifier_opt()]
+
   @doc """
   Converts the module into an `t:t/0`.
 
@@ -57,7 +59,7 @@ defmodule OnePiece.Commanded.Entity do
         end
       end
   """
-  @spec __using__(opts :: [identifier: identifier_opt()]) :: any()
+  @spec __using__(opts :: using_opts()) :: any()
   defmacro __using__(opts \\ []) do
     unless Keyword.has_key?(opts, :identifier) do
       raise ArgumentError, "missing :identifier key"

apps/one_piece_commanded/test/one_piece/commanded/command_router_test.exs

@@ -3,7 +3,9 @@ defmodule OnePiece.Commanded.CommandRouterTest do
 
   alias TestSupport.CommandRouterExample.{
     CommandRouter,
-    OpenBankAccount
+    OpenBankAccount,
+    CloseBankAccount,
+    BankAccount
   }
 
   @dispatch_opts [
@@ -16,6 +18,18 @@ defmodule OnePiece.Commanded.CommandRouterTest do
     :ok
   end
 
+  describe "identify_aggregate/1" do
+    test "identifies an aggregate" do
+      {:ok, result} =
+        %{uuid: "uuid-1"}
+        |> CloseBankAccount.new!()
+        |> CommandRouter.dispatch(@dispatch_opts)
+
+      assert result.aggregate_uuid == "bank-account2-uuid-1"
+      assert result.aggregate_state == %BankAccount{closed?: true, uuid: "uuid-1"}
+    end
+  end
+
   describe "dispatch_transaction/2" do
     test "dispatches a transaction" do
       {:ok, result} =

apps/one_piece_commanded/test/support/command_router_example/bank_account.ex

@@ -0,0 +1,25 @@
+defmodule TestSupport.CommandRouterExample.BankAccount do
+  @moduledoc false
+  use OnePiece.Commanded.Aggregate,
+    identifier: :uuid,
+    stream_prefix: "bank-account2-"
+
+  alias TestSupport.CommandRouterExample.{BankAccountOpened, BankAccountClosed}
+
+  embedded_schema do
+    field :closed?, :boolean, default: false
+  end
+
+  @impl OnePiece.Commanded.Aggregate
+  def apply(aggregate, %BankAccountOpened{} = event) do
+    aggregate
+    |> Map.put(:uuid, event.uuid)
+  end
+
+  @impl OnePiece.Commanded.Aggregate
+  def apply(aggregate, %BankAccountClosed{} = event) do
+    aggregate
+    |> Map.put(:uuid, event.uuid)
+    |> Map.put(:closed?, true)
+  end
+end

apps/one_piece_commanded/test/support/command_router_example/bank_account_closed.ex

@@ -0,0 +1,7 @@
+defmodule TestSupport.CommandRouterExample.BankAccountClosed do
+  @moduledoc false
+  use OnePiece.Commanded.Event, aggregate_identifier: :uuid
+
+  embedded_schema do
+  end
+end

apps/one_piece_commanded/test/support/command_router_example/close_bank_account.ex

@@ -0,0 +1,20 @@
+defmodule TestSupport.CommandRouterExample.CloseBankAccount do
+  @moduledoc false
+  use OnePiece.Commanded.CommandHandler
+
+  use OnePiece.Commanded.Command,
+    aggregate_identifier: :uuid
+
+  alias TestSupport.CommandRouterExample.{
+    BankAccountClosed,
+    CloseBankAccount,
+    BankAccount
+  }
+
+  embedded_schema do
+  end
+
+  def handle(%BankAccount{} = _aggregate, %CloseBankAccount{} = command) do
+    %BankAccountClosed{uuid: command.uuid}
+  end
+end

apps/one_piece_commanded/test/support/command_router_example/command_router.ex

@@ -1,5 +1,13 @@
 defmodule TestSupport.CommandRouterExample.CommandRouter do
   @moduledoc false
   use OnePiece.Commanded.CommandRouter
+
+  identify_aggregate(TestSupport.CommandRouterExample.BankAccount)
+
+  dispatch(TestSupport.CommandRouterExample.CloseBankAccount,
+    to: TestSupport.CommandRouterExample.CloseBankAccount,
+    aggregate: TestSupport.CommandRouterExample.BankAccount
+  )
+
   register_transaction_script(TestSupport.CommandRouterExample.OpenBankAccount)
 end