# frozen_string_literal: true
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>.
#
# 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
# 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.
#
# 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 <tt>1</tt>.
#
# 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 hash of expressions/numeric differences can also be passed in and evaluated.
#
# assert_difference ->{ Article.count } => 1, ->{ Notification.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, *args, &block)
expressions =
if expression.is_a?(Hash)
message = args[0]
expression
else
difference = args[0] || 1
message = args[1]
Hash[Array(expression).map { |e| [e, difference] }]
end
exps = expressions.keys.map { |e|
e.respond_to?(:call) ? e : lambda { eval(e, block.binding) }
}
before = exps.map(&:call)
retval = yield
expressions.zip(exps, before) do |(code, diff), exp, before_value|
error = "#{code.inspect} didn't change by #{diff}"
error = "#{message}.\n#{error}" if message
assert_equal(before_value + diff, exp.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
#
# A lambda can be passed in and evaluated.
#
# 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
#
# An array of expressions can also be passed in and evaluated.
#
# assert_no_difference [ 'Article.count', -> { Post.count } ] do
# post :create, params: { article: invalid_attributes }
# end
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
error = "#{expression.inspect} didn't change"
error = "#{error}. It was already #{to}" if before == to
error = "#{message}.\n#{error}" if message
assert before != after, error
unless to == UNTRACKED
error = "#{expression.inspect} didn't change to as expected\n"
error = "#{error}Expected: #{to.inspect}\n"
error = "#{error} Actual: #{after.inspect}"
error = "#{message}.\n#{error}" if message
assert to === after, error
end
retval
end
# Assertion that the result of evaluating an expression is not 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 before == after, error
retval
end
end
end
end
