Test if an expression is blank. Passes if object.blank? is true.
assert_blank [] # => true
# File lib/active_support/testing/assertions.rb, line 70 def assert_blank(object, message=nil) message ||= "#{object.inspect} is not blank" assert object.blank?, message end
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 error message can be specified.
assert_difference 'Article.count', -1, "An Article should be destroyed" do post :delete, :id => ... end
# File lib/active_support/testing/assertions.rb, line 37 def assert_difference(expression, difference = 1, message = nil, &block) b = block.send(:binding) exps = Array.wrap(expression) before = exps.map { |e| eval(e, b) } yield exps.each_with_index do |e, i| error = "#{e.inspect} didn't change by #{difference}" error = "#{message}.\n#{error}" if message assert_equal(before[i] + difference, eval(e, b), 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 destroyed" do post :create, :article => invalid_attributes end
# File lib/active_support/testing/assertions.rb, line 63 def assert_no_difference(expression, message = nil, &block) assert_difference expression, 0, message, &block end
Test if an expression is not blank. Passes if object.present? is true.
assert_present {:data => 'x' } # => true
# File lib/active_support/testing/assertions.rb, line 78 def assert_present(object, message=nil) message ||= "#{object.inspect} is blank" assert object.present?, message end