feat(ignore_actions): allow to ignore actions by configuration (#107)

.formatter.exs

@@ -7,6 +7,7 @@ spark_locals_without_parens = [
   change_tracking_mode: 1,
   define_attribute?: 1,
   domain: 1,
+  ignore_actions: 1,
   ignore_attributes: 1,
   include_versions?: 1,
   mixin: 1,

documentation/dsls/DSL:-AshPaperTrail.Resource.md

@@ -25,6 +25,7 @@ A section for configuring how versioning is derived for the resource.
 | [`attributes_as_attributes`](#paper_trail-attributes_as_attributes){: #paper_trail-attributes_as_attributes } | `list(atom)` | `[]` | A set of attributes that should be set as attributes on the version resource, instead of stored in the freeform `changes` map attribute. |
 | [`change_tracking_mode`](#paper_trail-change_tracking_mode){: #paper_trail-change_tracking_mode } | `:snapshot \| :changes_only \| :full_diff` | `:snapshot` | Changes are stored in a map attribute called `changes`.  The `change_tracking_mode` determines what's stored. See the getting started guide for more. |
 | [`ignore_attributes`](#paper_trail-ignore_attributes){: #paper_trail-ignore_attributes } | `list(atom)` | `[]` | A list of attributes that should be ignored. Typically you'll want to ignore your timestamps. The primary key is always ignored. |
+| [`ignore_actions`](#paper_trail-ignore_actions){: #paper_trail-ignore_actions } | `list(atom)` | `[]` | A list of actions that should not produce new versions. By default, no actions are ignored. |
 | [`mixin`](#paper_trail-mixin){: #paper_trail-mixin } | `atom \| mfa` |  | A module that defines a `using` macro or {module, function, arguments} tuple that will be mixed into the version resource. |
 | [`on_actions`](#paper_trail-on_actions){: #paper_trail-on_actions } | `list(atom)` |  | Which actions should produce new versions. By default, all create/update actions will produce new versions. |
 | [`reference_source?`](#paper_trail-reference_source?){: #paper_trail-reference_source? } | `boolean` | `true` | Whether or not to create a foreign key reference from the version to the source.  This should be set to `false` if you are allowing actual deletion of data. Only relevant for resources using the AshPostgres data layer. |

documentation/tutorials/getting-started-with-ash-paper-trail.md

@@ -20,6 +20,7 @@ use Ash.Resource,
     change_tracking_mode :changes_only # default is :snapshot
     store_action_name? true # default is false
     ignore_attributes [:inserted_at, :updated_at] # the primary keys are always ignored
+    ignore_actions [:destroy] # default is []
   end
 ```
 

lib/resource/changes/create_new_version.ex

@@ -7,9 +7,10 @@ defmodule AshPaperTrail.Resource.Changes.CreateNewVersion do
 
   @impl true
   def change(changeset, _, _) do
-    if changeset.action_type in [:create, :destroy] ||
-         (changeset.action_type == :update &&
-            changeset.action.name in AshPaperTrail.Resource.Info.on_actions(changeset.resource)) do
+    if changeset.action.name not in AshPaperTrail.Resource.Info.ignore_actions(changeset.resource) &&
+         (changeset.action_type in [:create, :destroy] ||
+            (changeset.action_type == :update &&
+               changeset.action.name in AshPaperTrail.Resource.Info.on_actions(changeset.resource))) do
       create_new_version(changeset)
     else
       changeset

lib/resource/info.ex

@@ -30,6 +30,11 @@ defmodule AshPaperTrail.Resource.Info do
     Spark.Dsl.Extension.get_opt(resource, [:paper_trail], :ignore_attributes, [])
   end
 
+  @spec ignore_actions(Spark.Dsl.t() | Ash.Resource.t()) :: [atom]
+  def ignore_actions(resource) do
+    Spark.Dsl.Extension.get_opt(resource, [:paper_trail], :ignore_actions, [])
+  end
+
   @spec mixin(Spark.Dsl.t() | Ash.Resource.t()) :: {module, atom, list} | module | nil
   def mixin(resource) do
     Spark.Dsl.Extension.get_opt(resource, [:paper_trail], :mixin, nil)

lib/resource/resource.ex

@@ -58,6 +58,13 @@ defmodule AshPaperTrail.Resource do
         A list of attributes that should be ignored. Typically you'll want to ignore your timestamps. The primary key is always ignored.
         """
       ],
+      ignore_actions: [
+        type: {:list, :atom},
+        default: [],
+        doc: """
+        A list of actions that should not produce new versions. By default, no actions are ignored.
+        """
+      ],
       mixin: [
         type: {:or, [:atom, :mfa]},
         default: nil,

test/ash_paper_trail_test.exs

@@ -508,4 +508,25 @@ defmodule AshPaperTrailTest do
       assert is_nil(updated_version.id)
     end
   end
+
+  describe "ignore_actions" do
+    test "no new version is created on destroy" do
+      assert %{subject: "subject", body: "body"} =
+               article = Articles.Article.create!("subject", "body")
+
+      assert :ok = Articles.Article.destroy!(article)
+
+      versions = Ash.read!(Articles.Article.Version) |> Enum.sort_by(& &1.version_inserted_at)
+
+      assert [
+               %{
+                 subject: "subject",
+                 body: "body",
+                 version_action_type: :create
+               }
+             ] = versions
+
+      refute Enum.any?(versions, &(&1.version_action_type == :destroy))
+    end
+  end
 end

test/support/articles/article.ex

@@ -13,6 +13,7 @@ defmodule AshPaperTrail.Test.Articles.Article do
   paper_trail do
     primary_key_type :integer
     attributes_as_attributes [:subject, :body]
+    ignore_actions [:destroy]
     change_tracking_mode :snapshot
   end