improvement: default actions

lib/ash/resource.ex

@@ -372,6 +372,17 @@ defmodule Ash.Resource do
     end
   end
 
+  @doc "Returns the configured default actions"
+  @spec default_actions(Ash.resource()) :: [:create | :read | :update | :destroy]
+  def default_actions(resource) do
+    Extension.get_opt(
+      resource,
+      [:actions],
+      :defaults,
+      [:create, :read, :update, :destroy]
+    )
+  end
+
   @doc "Returns all actions of a resource"
   @spec actions(Ash.resource()) :: [Ash.action()]
   def actions(resource) do

lib/ash/resource/dsl.ex

@@ -420,6 +420,19 @@ defmodule Ash.Resource.Dsl do
     imports: [
       Ash.Resource.Change.Builtins
     ],
+    schema: [
+      defaults: [
+        type: {:list, {:in, [:create, :read, :update, :destroy]}},
+        default: [:create, :read, :update, :destroy],
+        doc: """
+        By default, an action of each type is added to each resource.
+
+        If any other actions of that same type are added, the default of that type is *not*
+        added. If you wish to skip adding defaults of certain types, specify this option
+        with the defaults that you *do* want implemented.
+        """
+      ]
+    ],
     examples: [
       """
       actions do

lib/ash/resource/transformers/set_primary_actions.ex

@@ -11,11 +11,30 @@ defmodule Ash.Resource.Transformers.SetPrimaryActions do
   alias Ash.Dsl.Transformer
   alias Ash.Error.Dsl.DslError
 
-  def transform(_resource, dsl_state) do
+  @extension Ash.Resource.Dsl
+
+  def transform(resource, dsl_state) do
     dsl_state
     |> Transformer.get_entities([:actions])
     |> Enum.group_by(& &1.type)
+    |> Map.put_new(:read, [])
+    |> Map.put_new(:update, [])
+    |> Map.put_new(:create, [])
+    |> Map.put_new(:destroy, [])
     |> Enum.reduce_while({:ok, dsl_state}, fn
+      {type, []}, {:ok, dsl_state} ->
+        if type in Ash.Resource.default_actions(resource) do
+          {:ok, action} =
+            Transformer.build_entity(@extension, [:actions], type,
+              name: type,
+              primary?: true
+            )
+
+          {:cont, {:ok, Transformer.add_entity(dsl_state, [:actions], action)}}
+        else
+          {:cont, {:ok, dsl_state}}
+        end
+
       {type, [action]}, {:ok, dsl_state} ->
         {:cont,
          {:ok,

mix.exs

@@ -142,7 +142,7 @@ defmodule Ash.MixProject do
       {:sobelow, ">= 0.0.0", only: :dev, runtime: false},
       {:git_ops, "~> 2.0.1", only: :dev},
       {:picosat_elixir, "~> 0.1.5"},
-      {:nimble_options, "~> 0.3.0"},
+      {:nimble_options, "~> 0.3.5"},
       {:excoveralls, "~> 0.13.0", only: [:dev, :test]},
       {:mix_test_watch, "~> 1.0", only: :dev, runtime: false},
       {:parse_trans, "3.3.0", only: [:dev, :test], override: true}

test/resource/actions/actions_test.exs

@@ -19,6 +19,13 @@ defmodule Ash.Test.Dsl.Resource.Actions.ActionsTest do
     end
   end
 
+  test "default actions are added" do
+    defposts do
+    end
+
+    assert Ash.Resource.primary_action!(Post, :read)
+  end
+
   describe "validations" do
     test "raises if you have multiple primary actions for a type" do
       assert_raise(

test/resource/actions/create_test.exs

@@ -22,6 +22,7 @@ defmodule Ash.Test.Dsl.Resource.Actions.CreateTest do
     test "it creates an action" do
       defposts do
         actions do
+          defaults([])
           create :default
         end
       end

test/resource/actions/destroy_test.exs

@@ -22,6 +22,7 @@ defmodule Ash.Test.Dsl.Resource.Actions.DestroyTest do
     test "it creates an action" do
       defposts do
         actions do
+          defaults([])
           destroy :default
         end
       end

test/resource/actions/read_test.exs

@@ -22,6 +22,7 @@ defmodule Ash.Test.Dsl.Resource.Actions.ReadTest do
     test "it creates an action" do
       defposts do
         actions do
+          defaults([])
           read :default
         end
       end

test/resource/actions/update_test.exs

@@ -20,6 +20,7 @@ defmodule Ash.Test.Dsl.Resource.Actions.UpdateTest do
     test "it creates an action" do
       defposts do
         actions do
+          defaults([])
           update :default
         end
       end