module ActiveSupport module Testing module Assertions # Asserts that an expression is not truthy. Passes if object is # +nil+ or +false+. "Truthy" means "considered true in a conditional" # like if foo. # # assert_not nil # => true # assert_not false # => true # assert_not 'foo' # => Expected "foo" to be nil or false # # An error message can be specified. # # assert_not foo, 'foo should be false' def assert_not(object, message = nil) message ||= "Expected #{mu_pp(object)} to be nil or false" assert !object, 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, params: { article: {...} } # end # # An arbitrary expression is passed in and evaluated. # # assert_difference 'Article.last.comments(:reload).size' do # post :create, params: { comment: {...} } # end # # An arbitrary positive or negative difference can be specified. # The default is 1. # # assert_difference 'Article.count', -1 do # post :delete, params: { id: ... } # end # # An array of expressions can also be passed in and evaluated. # # assert_difference [ 'Article.count', 'Post.count' ], 2 do # post :create, params: { article: {...} } # end # # A lambda or a list of lambdas can be passed in and evaluated: # # assert_difference ->{ Article.count }, 2 do # post :create, params: { article: {...} } # end # # assert_difference [->{ Article.count }, ->{ Post.count }], 2 do # post :create, params: { article: {...} } # end # # An error message can be specified. # # assert_difference 'Article.count', -1, 'An Article should be destroyed' do # post :delete, params: { 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(&:call) retval = 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 retval 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, params: { article: invalid_attributes } # end # # An error message can be specified. # # assert_no_difference 'Article.count', 'An Article should not be created' do # post :create, params: { article: invalid_attributes } # end def assert_no_difference(expression, message = nil, &block) assert_difference expression, 0, message, &block end end end end