| Module | Test::Unit::Assertions |
| In: |
vendor/rails/activesupport/lib/active_support/core_ext/test/unit/assertions.rb
|
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 vendor/rails/activesupport/lib/active_support/core_ext/test/unit/assertions.rb, line 37
37: def assert_difference(expressions, difference = 1, message = nil, &block)
38: expression_evaluations = Array(expressions).collect{ |expression| lambda { eval(expression, block.send!(:binding)) } }
39:
40: original_values = expression_evaluations.inject([]) { |memo, expression| memo << expression.call }
41: yield
42: expression_evaluations.each_with_index do |expression, i|
43: assert_equal original_values[i] + difference, expression.call, message
44: end
45: 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 vendor/rails/activesupport/lib/active_support/core_ext/test/unit/assertions.rb, line 59
59: def assert_no_difference(expressions, message = nil, &block)
60: assert_difference expressions, 0, message, &block
61: end