Merge pull request #65 from brunohkbx/feat/add-history_query/1

feat: add function history_query/1

Author: narrowtux

lib/repo/queryable.ex

@@ -1,6 +1,8 @@
 defmodule ExAudit.Queryable do
   require Logger
 
+  import Ecto.Query, only: [from: 2, where: 3]
+
   defp version_schema() do
     Application.get_env(:ex_audit, :version_schema)
   end
@@ -16,8 +18,6 @@ defmodule ExAudit.Queryable do
   end
 
   def history(module, struct, opts) do
-    import Ecto.Query
-
     query =
       from(
         v in version_schema(),
@@ -74,6 +74,15 @@ defmodule ExAudit.Queryable do
     end
   end
 
+  def history_query(%{id: id, __struct__: struct}) do
+    from(
+        v in version_schema(),
+        where: v.entity_id == ^id,
+        where: v.entity_schema == ^struct,
+        order_by: [desc: :recorded_at]
+      )
+  end
+
   @drop_fields [:__meta__, :__struct__]
 
   def revert(module, version, opts) do

lib/repo/repo.ex

@@ -212,6 +212,10 @@ defmodule ExAudit.Repo do
       def revert(version, opts \\ []) do
         ExAudit.Queryable.revert(__MODULE__, version, opts)
       end
+
+      def history_query(struct) do
+        ExAudit.Queryable.history_query(struct)
+      end
     end
   end
 
@@ -228,6 +232,12 @@ defmodule ExAudit.Repo do
   """
   @callback history(struct, opts :: list) :: [version :: struct]
 
+  @doc """
+  Returns a query that gathers the version history for the given struct, ordered by the time the changes
+  happened from newest to oldest.
+  """
+  @callback history_query(struct) :: Ecto.Query.t()
+
   @doc """
   Undoes the changes made in the given version, as well as all of the following versions.
   Inserts a new version entry in the process, with the `:rollback` flag set to true

test/ex_audit_test.exs

@@ -245,4 +245,23 @@ defmodule ExAuditTest do
 
     assert 2 = Repo.aggregate(query, :count, :id)
   end
+
+  describe "history_query/1" do
+    setup do
+      params = %{
+        name: "Foo",
+        email: "[email protected]"
+      }
+
+      changeset = User.changeset(%User{}, params)
+
+      {:ok, user} = Repo.insert(changeset)
+
+      %{user: user}
+    end
+
+    test "returns a queryable", %{user: user} do
+     assert user |> Repo.history_query() |> Repo.all() |> Enum.count() == 1
+    end
+  end
 end