ActiveSupport::Testing::Assertions (original) (raw)

Methods

A

Instance Public methods

assert_changes(expression, message = nil, from: UNTRACKED, to: UNTRACKED, &block)Link

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

Source: show | on GitHub

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 = _assert_nothing_raised_or_warn("assert_changes", &block)

unless from == UNTRACKED rich_message = -> do error = "Expected change from #{from.inspect}, got #{before.inspect}" error = "#{message}.\n#{error}" if message error end assert from === before, rich_message end

after = exp.call

rich_message = -> do code_string = expression.respond_to?(:call) ? _callable_to_source_string(expression) : expression error = "#{code_string} didn't change" error = "#{error}. It was already #{to.inspect}" if before == to error = "#{message}.\n#{error}" if message error end refute_equal before, after, rich_message

unless to == UNTRACKED rich_message = -> do error = "Expected change to #{to.inspect}, got #{after.inspect}\n" error = "#{message}.\n#{error}" if message error end assert to === after, rich_message end

retval 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 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

Source: show | on GitHub

def assert_difference(expression, *args, &block) expressions = if expression.is_a?(Hash) message = args[0] expression else difference = args[0] || 1 message = args[1] Array(expression).index_with(difference) end

exps = expressions.keys.map { |e| e.respond_to?(:call) ? e : lambda { eval(e, block.binding) } } before = exps.map(&:call)

retval = _assert_nothing_raised_or_warn("assert_difference", &block)

expressions.zip(exps, before) do |(code, diff), exp, before_value| actual = exp.call rich_message = -> do code_string = code.respond_to?(:call) ? _callable_to_source_string(code) : code error = "#{code_string} didn't change by #{diff}, but by #{actual - before_value}" error = "#{message}.\n#{error}" if message error end assert_equal(before_value + diff, actual, rich_message) end

retval end

assert_no_changes(expression, message = nil, from: UNTRACKED, &block)Link

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

Provide the optional keyword argument :from to specify the expected initial value.

assert_no_changes -> { Status.all_good? }, from: true 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

Source: show | on GitHub

def assert_no_changes(expression, message = nil, from: UNTRACKED, &block) exp = expression.respond_to?(:call) ? expression : -> { eval(expression.to_s, block.binding) }

before = exp.call retval = _assert_nothing_raised_or_warn("assert_no_changes", &block)

unless from == UNTRACKED rich_message = -> do error = "Expected initial value of #{from.inspect}, got #{before.inspect}" error = "#{message}.\n#{error}" if message error end assert from === before, rich_message end

after = exp.call

rich_message = -> do code_string = expression.respond_to?(:call) ? _callable_to_source_string(expression) : expression error = "#{code_string} changed" error = "#{message}.\n#{error}" if message error end

if before.nil? assert_nil after, rich_message else assert_equal before, after, rich_message end

retval end

assert_no_difference(expression, message = nil, &block)Link

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

Source: show | on GitHub

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

assert_not(object, message = nil)Link

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'

Source: show | on GitHub

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

Source: show | on GitHub

def assert_nothing_raised yield.tap { assert(true) } rescue => error raise Minitest::UnexpectedError.new(error) end

Asserts that a block raises one of exp. This is an enhancement of the standard Minitest assertion method with the ability to test error messages.

assert_raises(ArgumentError, match: /incorrect param/i) do
  perform_service(param: 'exception')
end

Source: show | on GitHub

def assert_raises(*exp, match: nil, &block) error = super(*exp, &block) assert_match(match, error.message) if match error end