diff options
Diffstat (limited to 'activesupport/lib/active_support/testing/assertions.rb')
| -rw-r--r-- | activesupport/lib/active_support/testing/assertions.rb | 100 |
1 files changed, 100 insertions, 0 deletions
diff --git a/activesupport/lib/active_support/testing/assertions.rb b/activesupport/lib/active_support/testing/assertions.rb index ad83638572..28cf2953bf 100644 --- a/activesupport/lib/active_support/testing/assertions.rb +++ b/activesupport/lib/active_support/testing/assertions.rb @@ -1,6 +1,8 @@ module ActiveSupport module Testing module Assertions + UNTRACKED = Object.new # :nodoc: + # Asserts that an expression is not truthy. Passes if <tt>object</tt> is # +nil+ or +false+. "Truthy" means "considered true in a conditional" # like <tt>if foo</tt>. @@ -17,6 +19,17 @@ module ActiveSupport assert !object, message end + # Assertion that the block should not raise an exception. + # + # Passes if evaluated code in the yielded block raises no exception. + # + # assert_nothing_raised do + # perform_service(param: 'no_exception') + # end + def assert_nothing_raised + yield + end + # Test numeric difference between the return value of an expression as a # result of what is evaluated in the yielded block. # @@ -92,6 +105,93 @@ module ActiveSupport def assert_no_difference(expression, message = nil, &block) assert_difference expression, 0, message, &block end + + # Assertion that the result of evaluating an expression is changed before + # and after invoking the passed in block. + # + # assert_changes 'Status.all_good?' do + # post :create, params: { status: { ok: false } } + # end + # + # You can pass the block as a string to be evaluated in the context of + # the block. A lambda can be passed for the block as well. + # + # assert_changes -> { Status.all_good? } do + # post :create, params: { status: { ok: false } } + # end + # + # The assertion is useful to test side effects. The passed block can be + # anything that can be converted to string with #to_s. + # + # assert_changes :@object do + # @object = 42 + # end + # + # The keyword arguments :from and :to can be given to specify the + # expected initial value and the expected value after the block was + # executed. + # + # assert_changes :@object, from: nil, to: :foo do + # @object = :foo + # end + # + # An error message can be specified. + # + # assert_changes -> { Status.all_good? }, 'Expected the status to be bad' do + # post :create, params: { status: { incident: true } } + # end + def assert_changes(expression, message = nil, from: UNTRACKED, to: UNTRACKED, &block) + exp = expression.respond_to?(:call) ? expression : -> { eval(expression.to_s, block.binding) } + + before = exp.call + retval = yield + + unless from == UNTRACKED + error = "#{expression.inspect} isn't #{from.inspect}" + error = "#{message}.\n#{error}" if message + assert from === before, error + end + + after = exp.call + + if to == UNTRACKED + error = "#{expression.inspect} didn't changed" + error = "#{message}.\n#{error}" if message + assert_not_equal before, after, error + else + error = "#{expression.inspect} didn't change to #{to}" + error = "#{message}.\n#{error}" if message + assert to === after, error + end + + retval + end + + # Assertion that the result of evaluating an expression is changed before + # and after invoking the passed in block. + # + # assert_no_changes 'Status.all_good?' do + # post :create, params: { status: { ok: true } } + # end + # + # An error message can be specified. + # + # assert_no_changes -> { Status.all_good? }, 'Expected the status to be good' do + # post :create, params: { status: { ok: false } } + # end + def assert_no_changes(expression, message = nil, &block) + exp = expression.respond_to?(:call) ? expression : -> { eval(expression.to_s, block.binding) } + + before = exp.call + retval = yield + after = exp.call + + error = "#{expression.inspect} did change to #{after}" + error = "#{message}.\n#{error}" if message + assert_equal before, after, error + + retval + end end end end |