Module: ActiveSupport::Testing::Assertions

Included in:
ActiveSupport::TestCase
Defined in:
activesupport/lib/active_support/testing/assertions.rb

Instance Method Summary (collapse)

Instance Method Details

- (Object) assert_blank(object, message = nil)

Test if an expression is blank. Passes if object.blank? is true.

assert_blank [] # => true


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# File 'activesupport/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

- (Object) assert_difference(expression, difference = 1, message = nil, &block)

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


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# File 'activesupport/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

- (Object) assert_no_difference(expression, message = nil, &block)

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


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# File 'activesupport/lib/active_support/testing/assertions.rb', line 63

def assert_no_difference(expression, message = nil, &block)
  assert_difference expression, 0, message, &block
end

- (Object) assert_present(object, message = nil)

Test if an expression is not blank. Passes if object.present? is true.

assert_present {:data => 'x' } # => true


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# File 'activesupport/lib/active_support/testing/assertions.rb', line 78

def assert_present(object, message=nil)
  message ||= "#{object.inspect} is blank"
  assert object.present?, message
end