Add new columns and sorting to admin users list (#1004)

* Add trial end date to admin users list

* Add new columns

* Regression

test/controllers/admin/users_controller_test.rb

@@ -0,0 +1,28 @@
+require "test_helper"
+
+class Admin::UsersControllerTest < ActionDispatch::IntegrationTest
+  setup do
+    sign_in users(:sure_support_staff)
+  end
+
+  test "index sorts users by subscription trial end date with nils last" do
+    get admin_users_url
+
+    assert_response :success
+
+    body = response.body
+    trial_user_index = body.index("user1@example.com")
+    no_trial_user_index = body.index("bob@bobdylan.com")
+
+    assert_not_nil trial_user_index
+    assert_not_nil no_trial_user_index
+    assert_operator trial_user_index, :<, no_trial_user_index
+  end
+
+  test "index shows n/a when trial end date is unavailable" do
+    get admin_users_url
+
+    assert_response :success
+    assert_match(/n\/a/, response.body, "Page should show n/a for users without trial end date")
+  end
+end