ActiveSupport::Testing::Assertions

Test numeric difference between the return value of an expression as a result of what is evaluated in the yielded block.

assert_difference 'Article.count' do
  post :create, article: {...}
end

An arbitrary expression is passed in and evaluated.

assert_difference 'assigns(:article).comments(:reload).size' do
  post :create, comment: {...}
end登录查看完整内容