require 'active_support/core_ext/object/blank' module ActiveSupport module Testing module 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 # # An arbitrary positive or negative difference can be specified. The default is +1. # # assert_difference 'Article.count', -1 do # post :delete, :id => ... # end # # An array of expressions can also be passed in and evaluated. # # assert_difference [ 'Article.count', 'Post.count' ], +2 do # post :create, :article => {...} # end # # A lambda or a list of lambdas can be passed in and evaluated: # # assert_difference lambda { Article.count }, 2 do # post :create, :article => {...} # end # # assert_difference [->{ Article.count }, ->{ Post.count }], 2 do # post :create, :article => {...} # end # # A error message can be specified. # # assert_difference 'Article.count', -1, "An Article should be destroyed" do # post :delete, :id => ... # end def assert_difference(expression, difference = 1, message = nil, &block) expressions = Array(expression) exps = expressions.map { |e| e.respond_to?(:call) ? e : lambda { eval(e, block.binding) } } before = exps.map { |e| e.call } yield expressions.zip(exps).each_with_index do |(code, e), i| error = "#{code.inspect} didn't change by #{difference}" error = "#{message}.\n#{error}" if message assert_equal(before[i] + difference, e.call, error) end end # Assertion that the numeric result of evaluating an expression is not changed before and after # invoking the passed in block. # # assert_no_difference 'Article.count' do # post :create, :article => invalid_attributes # end # # A error message can be specified. # # assert_no_difference 'Article.count', "An Article should not be created" do # post :create, :article => invalid_attributes # end def assert_no_difference(expression, message = nil, &block) assert_difference expression, 0, message, &block end # Test if an expression is blank. Passes if object.blank? is true. # # assert_blank [] # => true def assert_blank(object, message=nil) message ||= "#{object.inspect} is not blank" assert object.blank?, message end # Test if an expression is not blank. Passes if object.present? is true. # # assert_present({:data => 'x' }) # => true def assert_present(object, message=nil) message ||= "#{object.inspect} is blank" assert object.present?, message end end end end