v1.rb

it 'updates categories' do
  expect {
    put :update_categories, id: contents(:adsl_cancel_question).id, category_ids: [categories(:mobile).id, categories(:technical).id], thread_id: content_threads(:adsl_cancel).id
  }.to change { contents(:adsl_cancel_question).reload.categories.to_a.sort }.from(array_including([categories(:internet), categories(:sales)])).to(array_including([categories(:technical), categories(:mobile)]))
end

v2.rb

# Variables created with let are shared accross all tests
let(:content) { contents(:adsl_cancel_question).set(intervention: nil) }
let(:category_mobile) { categories(:mobile) }
let(:category_technical) { categories(:technical) }
let(:category_internet) { categories(:internet) }
let(:category_sales) { categories(:sales) }
let(:category_departement) { categories(:department) }
let(:thread) { content_threads(:adsl_cancel) }

it 'updates categories' do
  expect {
    put :update_categories, 
    id: content.id, 
    category_ids: [category_mobile.id, category_technical.id], 
    thread_id: thread.id
  }.to change { 
    content.reload.categories.to_a.sort 
  }.from(array_including([category_internet, category_sales]))
    .to(array_including([category_technical, category_mobile]))
end

v3.rb

# Variables created with let are shared accross all tests
let(:content) { contents(:adsl_cancel_question).set(intervention: nil) }
let(:category_mobile) { categories(:mobile) }
let(:category_technical) { categories(:technical) }
let(:category_internet) { categories(:internet) }
let(:category_sales) { categories(:sales) }
let(:category_departement) { categories(:department) }
let(:thread) { content_threads(:adsl_cancel) }

it 'updates categories' do
  expect(content.categories).to include(category_internet, category_sales)
  put :update_categories,
    id: content.id,
    category_ids: [category_mobile.id, category_technical.id],
    thread_id: thread.id
  expect(content.reload.categories.to_a).to include(category_mobile, category_technical)
end

v4.rb

it 'updates categories' do
  expect {
    put :update_categories,
      id: contents(:adsl_cancel_question).id,
      category_ids: [categories(:mobile).id, categories(:technical).id],
      thread_id: content_threads(:adsl_cancel).id
  }.to change {
    contents(:adsl_cancel_question).reload.categories.to_a.sort
  }.from(array_including([categories(:internet), categories(:sales)]))
    .to(array_including([categories(:technical), categories(:mobile)]))
end

v5.rb

it 'updates categories' do
  expect(contents(:adsl_cancel_question)).to include(categories(:internet), categories(:sales))

  put :update_categories,
    id: contents(:adsl_cancel_question).id,
    category_ids: [categories(:mobile).id, categories(:technical).id],
    thread_id: content_threads(:adsl_cancel).id

  expect(contents(:adsl_cancel_question).reload.categories.to_a)
    .to include(categories(:technical), categories(:mobile))
end