RSpec.describe Rails::Auth::ErrorPage::Middleware do let(:request) { Rack::MockRequest.env_for("https://www.example.com") } let(:error_page) { "

Unauthorized!!!

" } subject(:middleware) { described_class.new(app, page_body: error_page) } context "access granted" do let(:code) { 200 } let(:app) { ->(env) { [code, env, "Hello, world!"] } } it "renders the expected response" do response = middleware.call(request) expect(response.first).to eq code end end context "access denied" do let(:app) { ->(_env) { fail(Rails::Auth::NotAuthorizedError, "not authorized!") } } it "renders the error page" do code, _env, body = middleware.call(request) expect(code).to eq 403 expect(body).to eq [error_page] end end end