Testing XmlBuilder with Rspec - ruby-on-rails

Question

I posted a question (Rails XML builder not rendering) regarding rendering XML using XmlBuilder. That particular issue was resolved but I’ve run into another issue testing this controller action.
The issue seems to be with Rspec as because the same test written in Minitest works fine and using cURL works too.
While debugging this, Rspec never tries to render the xml builder template. It just skips over the template and renders a http status 200 with a blank body.
Here are the controller, xml builder, tests, and test results:
controllers/bars_controller.rb
require 'builder'
class BarsController < ApplicationController
def show
#bar = Bar.find(params[:id])
render template: 'bars/show.xml.builder', formats: [:xml]
end
end
/views/bars/show.xml.builder
xml.instruct!
xml.bar do
xml.foo(#bar.foo)
xml.bar(#bar.bar)
end
/test/controllers/bars_controller_test.rb
require 'test_helper'
class BarsControllerTest < ActionController::TestCase
setup do
#bar = Bar.create(foo: 'bar', bar: 'foo')
end
test "should show bar" do
get :show, id: #bar
assert_response :success
assert_match "<bar>", response.body
end
end
/spec/controllers/bars_controller_spec.rb
require_relative '../rails_helper'
describe BarsController do
describe 'a POST to :show' do
before do
#bar = Bar.create(foo: 'bar', bar: 'foo')
post :show, id: #bar
end
it 'should show bar' do
expect(response).to be_success
expect(response.body).to include("<bar>")
end
end
end
Test results
> rake test
Run options: --seed 50688
# Running:
.
Finished in 0.096901s, 10.3198 runs/s, 30.9593 assertions/s.
1 runs, 3 assertions, 0 failures, 0 errors, 0 skips
> rspec spec/controllers/bars_controller_spec.rb
F
Failures:
1) BarsController a POST to :show responds with xml bar
Failure/Error: expect(response.body).to include("<bar>")
expected "" to include "<bar>"
# ./spec/controllers/bars_controller_spec.rb:13:in `block (3 levels) in <top (required)>'
Finished in 0.01726 seconds (files took 1.53 seconds to load)
1 example, 1 failure
Failed examples:
rspec ./spec/controllers/bars_controller_spec.rb:11 # BarsController a POST to :show responds with xml bar

Answer 1

RSpec controller tests do not render views by default. In order to render the views, add render_views to the describe block:
describe 'a POST to :show' do
render_views
before do
#bar = Bar.create(foo: 'bar', bar: 'foo')
post :show, id: #bar
end
it 'should show bar' do
expect(response).to be_success
expect(response.body).to include("<bar>")
end
end