From https://once.com/writebook

test/controllers/books/leaves/moves_controller_test.rb

@@ -0,0 +1,25 @@
+require "test_helper"
+
+class Books::Leaves::MovesControllerTest < ActionDispatch::IntegrationTest
+  setup do
+    sign_in :kevin
+  end
+
+  test "moving a single item" do
+    assert_equal [ leaves(:welcome_section), leaves(:welcome_page), leaves(:summary_page), leaves(:reading_picture) ], books(:handbook).leaves.positioned
+
+    post book_leaves_moves_url(books(:handbook), id: leaves(:welcome_page).id, position: 0)
+    assert_response :no_content
+
+    assert_equal [ leaves(:welcome_page), leaves(:welcome_section), leaves(:summary_page), leaves(:reading_picture) ], books(:handbook).leaves.positioned
+  end
+
+  test "moving multiple items" do
+    assert_equal [ leaves(:welcome_section), leaves(:welcome_page), leaves(:summary_page), leaves(:reading_picture) ], books(:handbook).leaves.positioned
+
+    post book_leaves_moves_url(books(:handbook), id: leaves(:summary_page, :reading_picture).map(&:id), position: 1)
+    assert_response :no_content
+
+    assert_equal [ leaves(:welcome_section), leaves(:summary_page), leaves(:reading_picture), leaves(:welcome_page) ], books(:handbook).leaves.positioned
+  end
+end