add move node function

lib/radiator/outline.ex

@@ -107,6 +107,25 @@ defmodule Radiator.Outline do
     |> broadcast_node_action(:update)
   end
 
+  @doc """
+  Moves a nodes to another parent.
+
+  ## Examples
+
+      iex> move_node(node, %Node{uuid: new_parent_id})
+      {:ok, %Node{}}
+
+      iex> move_node(node, nil)
+      {:error, %Ecto.Changeset{}}
+
+  """
+  def move_node(%Node{} = node, %Node{} = parent_node) do
+    node
+    |> Node.move_changeset(parent_node)
+    |> Repo.update()
+    |> broadcast_node_action(:update)
+  end
+
   @doc """
   Deletes a node.
 

lib/radiator/outline/node.ex

@@ -41,9 +41,10 @@ defmodule Radiator.Outline.Node do
   Changeset for moving a node
   Only the parent_id is allowed and expected to be changed
   """
-  def move_changeset(node, attrs) do
+  def move_changeset(node, new_parent_node) do
     node
-    |> cast(attrs, [:parent_id])
+    |> cast(%{parent_id: new_parent_node.uuid}, [:parent_id])
+    |> validate_parent(new_parent_node)
   end
 
   @doc """
@@ -58,4 +59,22 @@ defmodule Radiator.Outline.Node do
 
   defp trim(content) when is_binary(content), do: String.trim(content)
   defp trim(content), do: content
+
+  defp validate_parent(changeset, nil), do: add_error(changeset, :parent_id, "must not be nil")
+
+  defp validate_parent(changeset, parent_node) do
+    cond do
+      parent_node.uuid == changeset.data.uuid ->
+        add_error(changeset, :parent_id, "must not be the same as the node itself")
+
+      parent_node.parent_id == changeset.data.uuid ->
+        add_error(changeset, :parent_id, "node is already parent of the parent node")
+
+      parent_node.episode_id != changeset.data.episode_id ->
+        add_error(changeset, :parent_id, "nodes must be in the same episode")
+
+      true ->
+        changeset
+    end
+  end
 end

test/radiator/outline_test.exs

@@ -3,41 +3,45 @@ defmodule Radiator.OutlineTest do
 
   alias Radiator.Outline
 
-  describe "outline_nodes" do
-    alias Radiator.Outline.Node
+  alias Radiator.Outline.Node
 
-    import Radiator.OutlineFixtures
-    alias Radiator.PodcastFixtures
+  import Radiator.OutlineFixtures
+  alias Radiator.PodcastFixtures
 
-    @invalid_attrs %{content: nil}
+  @invalid_attrs %{content: nil}
 
-    test "list_nodes/0 returns all nodes" do
+  describe "list_nodes/0" do
+    test "returns all nodes" do
       node = node_fixture()
       assert Outline.list_nodes() == [node]
     end
+  end
 
-    test "get_node!/1 returns the node with given id" do
+  describe "get_node!/1" do
+    test "returns the node with given id" do
       node = node_fixture()
       assert Outline.get_node!(node.uuid) == node
     end
+  end
 
-    test "create_node/1 with valid data creates a node" do
+  describe "create_node/1" do
+    test "with valid data creates a node" do
       episode = PodcastFixtures.episode_fixture()
       valid_attrs = %{content: "some content", episode_id: episode.id}
 
       assert {:ok, %Node{} = node} = Outline.create_node(valid_attrs)
       assert node.content == "some content"
     end
 
-    test "create_node/1 trims whitespace from content" do
+    test "trims whitespace from content" do
       episode = PodcastFixtures.episode_fixture()
       valid_attrs = %{content: "  some content  ", episode_id: episode.id}
 
       assert {:ok, %Node{} = node} = Outline.create_node(valid_attrs)
       assert node.content == "some content"
     end
 
-    test "create_node/1 can have a creator" do
+    test "can have a creator" do
       episode = PodcastFixtures.episode_fixture()
       user = %{id: 2}
       valid_attrs = %{content: "some content", episode_id: episode.id}
@@ -47,25 +51,48 @@ defmodule Radiator.OutlineTest do
       assert node.creator_id == user.id
     end
 
-    test "create_node/1 with invalid data returns error changeset" do
+    test "with invalid data returns error changeset" do
       assert {:error, %Ecto.Changeset{}} = Outline.create_node(@invalid_attrs)
     end
+  end
 
-    test "update_node_content/2 with valid data updates the node" do
+  describe "update_node_content/2" do
+    test "with valid data updates the node" do
       node = node_fixture()
       update_attrs = %{content: "some updated content"}
 
       assert {:ok, %Node{} = node} = Outline.update_node_content(node, update_attrs)
       assert node.content == "some updated content"
     end
 
-    test "update_node_content/2 with invalid data returns error changeset" do
+    test "with invalid data returns error changeset" do
       node = node_fixture()
       assert {:error, %Ecto.Changeset{}} = Outline.update_node_content(node, @invalid_attrs)
       assert node == Outline.get_node!(node.uuid)
     end
+  end
+
+  describe "move_node/2" do
+    test "moves node to another parent" do
+      node = node_fixture()
+      new_parent = node_fixture(episode_id: node.episode_id)
+
+      assert {:ok, %Node{} = node} = Outline.move_node(node, new_parent)
+      assert node.parent_id == new_parent.uuid
+    end
+
+    test "update_node_content/2 with parent from another episode returns error changeset" do
+      node = node_fixture()
+      new_bad_parent = node_fixture()
+      assert node.episode_id != new_bad_parent.episode_id
+
+      assert {:error, %Ecto.Changeset{}} = Outline.move_node(node, new_bad_parent)
+      assert node == Outline.get_node!(node.uuid)
+    end
+  end
 
-    test "delete_node/1 deletes the node" do
+  describe "delete_node/1" do
+    test "deletes the node" do
       node = node_fixture()
       assert {:ok, %Node{}} = Outline.delete_node(node)
       assert_raise Ecto.NoResultsError, fn -> Outline.get_node!(node.uuid) end