From https://once.com/writebook

test/controllers/pages/edits_controller_test.rb

@@ -0,0 +1,26 @@
+require "test_helper"
+
+class Pages::EditsControllerTest < ActionDispatch::IntegrationTest
+  setup do
+    sign_in :kevin
+  end
+
+  test "show an edit" do
+    leaves(:welcome_page).edit leafable_params: { body: "Completely new content" }
+
+    get page_edit_url(leaves(:welcome_page), leaves(:welcome_page).edits.last)
+
+    assert_response :success
+    assert_select "p", /such a great handbook/
+    assert_select "p", /Completely new content/
+  end
+
+  test "show latest edit" do
+    leaves(:welcome_page).edit leafable_params: { body: "Updated" }
+
+    get page_edit_url(leaves(:welcome_page), "latest")
+
+    assert_response :success
+    assert_select "p", /such a great handbook/
+  end
+end