Module: Minitest::Assertions
| Relationships & Source Files | |
| Extension / Inclusion / Inheritance Descendants | |
|
Included In:
| |
| Defined in: | lib/minitest/assertions.rb, lib/minitest/mock.rb |
Overview
::Minitest Assertions. All assertion methods accept a msg which is printed if the assertion fails.
Protocol: Nearly everything here boils up to #assert, which expects to be able to increment an instance accessor named assertions. This is not provided by Assertions and must be provided by the thing including Assertions. See Runnable for an example.
Constant Summary
-
E =
Internal use only
# File 'lib/minitest/assertions.rb', line 199"" -
UNDEFINED =
Internal use only
# File 'lib/minitest/assertions.rb', line 17Object.new
Class Attribute Summary
Instance Attribute Summary
-
#skipped? ⇒ Boolean
readonly
Was this testcase skipped? Meant for
#teardown.
Instance Method Summary
-
#assert(test, msg = nil)
Fails unless
testis truthy. -
#assert_empty(obj, msg = nil)
Fails unless
objis empty. -
#assert_equal(exp, act, msg = nil)
Fails unless
exp == actprinting the difference between the two, if possible. -
#assert_in_delta(exp, act, delta = 0.001, msg = nil)
For comparing Floats.
-
#assert_in_epsilon(exp, act, epsilon = 0.001, msg = nil)
For comparing Floats.
-
#assert_includes(collection, obj, msg = nil)
Fails unless
collectionincludesobj. -
#assert_instance_of(cls, obj, msg = nil)
Fails unless
objis an instance ofcls. -
#assert_kind_of(cls, obj, msg = nil)
Fails unless
objis a kind ofcls. -
#assert_match(matcher, obj, msg = nil)
Fails unless
matcher=~obj. -
#assert_mock(mock)
Assert that the mock verifies correctly.
-
#assert_nil(obj, msg = nil)
Fails unless
objis nil. -
#assert_operator(o1, op, o2 = UNDEFINED, msg = nil)
For testing with binary operators.
-
#assert_output(stdout = nil, stderr = nil)
Fails if stdout or stderr do not output the expected results.
-
#assert_path_exists(path, msg = nil)
Fails unless
pathexists. -
#assert_pattern
For testing with pattern matching (only supported with Ruby 3.0 and later).
-
#assert_predicate(o1, op, msg = nil)
For testing with predicates.
-
#assert_raises(*exp)
Fails unless the block raises one of
exp. -
#assert_respond_to(obj, meth, msg = nil, include_all: false)
Fails unless
objresponds tometh. -
#assert_same(exp, act, msg = nil)
Fails unless
expandactare#equal? -
#assert_send(send_ary, m = nil)
send_aryis a receiver, message and arguments. -
#assert_silent
Fails if the block outputs anything to stderr or stdout.
-
#assert_throws(sym, msg = nil)
Fails unless the block throws
sym -
#capture_io
Captures $stdout and $stderr into strings:
-
#capture_subprocess_io
Captures $stdout and $stderr into strings, using Tempfile to ensure that subprocess IO is captured as well.
-
#diff(exp, act)
Returns a diff between
expandact. -
#exception_details(e, msg)
Returns details for exception
e. -
#fail_after(y, m, d, msg)
Fails after a given date (in the local time zone).
-
#flunk(msg = nil)
Fails with
msg. -
#message(msg = nil, ending = nil, &default)
Returns a proc that will output
msgalong with the default message. -
#mu_pp(obj)
This returns a human-readable version of
obj. -
#mu_pp_for_diff(obj)
This returns a diff-able more human-readable version of
obj. -
#pass(_msg = nil)
used for counting assertions.
-
#refute(test, msg = nil)
Fails if
testis truthy. -
#refute_empty(obj, msg = nil)
Fails if
objis empty. -
#refute_equal(exp, act, msg = nil)
Fails if
exp == act. -
#refute_in_delta(exp, act, delta = 0.001, msg = nil)
For comparing Floats.
-
#refute_in_epsilon(a, b, epsilon = 0.001, msg = nil)
For comparing Floats.
-
#refute_includes(collection, obj, msg = nil)
Fails if
collectionincludesobj. -
#refute_instance_of(cls, obj, msg = nil)
Fails if
objis an instance ofcls. -
#refute_kind_of(cls, obj, msg = nil)
Fails if
objis a kind ofcls. -
#refute_match(matcher, obj, msg = nil)
Fails if
matcher=~obj. -
#refute_nil(obj, msg = nil)
Fails if
objis nil. -
#refute_operator(o1, op, o2 = UNDEFINED, msg = nil)
Fails if
o1is notopo2. -
#refute_path_exists(path, msg = nil)
Fails if
pathexists. -
#refute_pattern
For testing with pattern matching (only supported with Ruby 3.0 and later).
-
#refute_predicate(o1, op, msg = nil)
For testing with predicates.
-
#refute_respond_to(obj, meth, msg = nil, include_all: false)
Fails if
objresponds to the messagemeth. -
#refute_same(exp, act, msg = nil)
Fails if
expis the same (by object identity) asact. -
#skip(msg = nil, _ignored = nil)
Skips the current run.
-
#skip_until(y, m, d, msg)
Skips the current run until a given date (in the local time zone).
-
#things_to_diff(exp, act)
Returns things to diff [expect, butwas], or [nil, nil] if nothing to diff.
- #_synchronize Internal use only
- #_where Internal use only
Class Attribute Details
.diff (rw)
Returns the diff command to use in #diff. Tries to intelligently figure out what diff to use.
# File 'lib/minitest/assertions.rb', line 27
def self.diff return @diff if defined? @diff @diff = if (RbConfig::CONFIG["host_os"] =~ /mswin|mingw/ and system "diff.exe", __FILE__, __FILE__) then "diff.exe -u" elsif system "gdiff", __FILE__, __FILE__ then "gdiff -u" # solaris and kin suck elsif system "diff", __FILE__, __FILE__ then "diff -u" else nil end end
.diff=(o) (rw)
Set the diff command to use in #diff.
# File 'lib/minitest/assertions.rb', line 45
def self.diff= o @diff = o end
Instance Attribute Details
#skipped? ⇒ Boolean (readonly)
Was this testcase skipped? Meant for #teardown.
# File 'lib/minitest/assertions.rb', line 851
def skipped? defined?(@skip) and @skip end
Instance Method Details
#_synchronize
# File 'lib/minitest/assertions.rb', line 181
def _synchronize # :nodoc: yield end
#_where
# File 'lib/minitest/assertions.rb', line 194
def _where # :nodoc: Minitest.filter_backtrace(caller).first .split(":in ", 2).first # clean up noise end
#assert(test, msg = nil)
Fails unless test is truthy.
#assert_empty(obj, msg = nil)
Fails unless obj is empty.
# File 'lib/minitest/assertions.rb', line 188
def assert_empty obj, msg = nil msg = (msg) { "Expected #{mu_pp obj} to be empty" } assert_respond_to obj, :empty? assert obj.empty?, msg end
#assert_equal(exp, act, msg = nil)
Fails unless exp == act printing the difference between the two, if possible.
If there is no visible difference but the assertion fails, you should suspect that your #== is buggy, or your inspect output is missing crucial details. For nicer structural diffing, set Test.make_my_diffs_pretty!
For floats use assert_in_delta.
See also: .diff
# File 'lib/minitest/assertions.rb', line 214
def assert_equal exp, act, msg = nil msg = (msg, E) { diff exp, act } result = assert exp == act, msg if nil == exp then if Minitest::VERSION >= "6" then refute_nil exp, "Use assert_nil if expecting nil." else warn "DEPRECATED: Use assert_nil if expecting nil from #{_where}. This will fail in Minitest 6." end end result end
#assert_in_delta(exp, act, delta = 0.001, msg = nil)
For comparing Floats. Fails unless exp and act are within delta of each other.
assert_in_delta Math::PI, (22.0 / 7.0), 0.01
# File 'lib/minitest/assertions.rb', line 235
def assert_in_delta exp, act, delta = 0.001, msg = nil n = (exp - act).abs msg = (msg) { "Expected |#{exp} - #{act}| (#{n}) to be <= #{delta}" } assert delta >= n, msg end
#assert_in_epsilon(exp, act, epsilon = 0.001, msg = nil)
For comparing Floats. Fails unless exp and act have a relative error less than epsilon.
# File 'lib/minitest/assertions.rb', line 247
def assert_in_epsilon exp, act, epsilon = 0.001, msg = nil assert_in_delta exp, act, [exp.abs, act.abs].min * epsilon, msg end
#assert_includes(collection, obj, msg = nil)
Fails unless collection includes obj.
# File 'lib/minitest/assertions.rb', line 254
def assert_includes collection, obj, msg = nil msg = (msg) { "Expected #{mu_pp collection} to include #{mu_pp obj}" } assert_respond_to collection, :include? assert collection.include?(obj), msg end
#assert_instance_of(cls, obj, msg = nil)
Fails unless obj is an instance of cls.
#assert_kind_of(cls, obj, msg = nil)
Fails unless obj is a kind of cls.
#assert_match(matcher, obj, msg = nil)
Fails unless matcher =~ obj.
# File 'lib/minitest/assertions.rb', line 287
def assert_match matcher, obj, msg = nil msg = (msg) { "Expected #{mu_pp matcher} to match #{mu_pp obj}" } assert_respond_to matcher, :=~ matcher = Regexp.new Regexp.escape matcher if String === matcher assert matcher =~ obj, msg Regexp.last_match end
#assert_mock(mock)
Assert that the mock verifies correctly.
# File 'lib/minitest/mock.rb', line 250
def assert_mock mock assert mock.verify end
#assert_nil(obj, msg = nil)
Fails unless obj is nil
#assert_operator(o1, op, o2 = UNDEFINED, msg = nil)
For testing with binary operators. Eg:
assert_operator 5, :<=, 4
#assert_output(stdout = nil, stderr = nil)
Fails if stdout or stderr do not output the expected results. Pass in nil if you don’t care about that streams output. Pass in “” if you require it to be silent. Pass in a regexp if you want to pattern match.
assert_output(/hey/) { method_with_output }
NOTE: this uses #capture_io, not #capture_subprocess_io.
See also: #assert_silent
# File 'lib/minitest/assertions.rb', line 327
def assert_output stdout = nil, stderr = nil flunk "assert_output requires a block to capture output." unless block_given? out, err = capture_io do yield end err_msg = Regexp === stderr ? :assert_match : :assert_equal if stderr out_msg = Regexp === stdout ? :assert_match : :assert_equal if stdout y = send err_msg, stderr, err, "In stderr" if err_msg x = send out_msg, stdout, out, "In stdout" if out_msg (!stdout || x) && (!stderr || y) rescue Assertion raise rescue => e raise UnexpectedError, e end
#assert_path_exists(path, msg = nil)
Fails unless path exists.
# File 'lib/minitest/assertions.rb', line 351
def assert_path_exists path, msg = nil msg = (msg) { "Expected path '#{path}' to exist" } assert File.exist?(path), msg end
#assert_pattern
For testing with pattern matching (only supported with Ruby 3.0 and later)
# pass
assert_pattern { [1,2,3] => [Integer, Integer, Integer] }
# fail "length mismatch (given 3, expected 1)"
assert_pattern { [1,2,3] => [Integer] }
The bare => pattern will raise a NoMatchingPatternError on failure, which would normally be counted as a test error. This assertion rescues NoMatchingPatternError and generates a test failure. Any other exception will be raised as normal and generate a test error.
# File 'lib/minitest/assertions.rb', line 370
def assert_pattern raise NotImplementedError, "only available in Ruby 3.0+" unless RUBY_VERSION >= "3.0" flunk "assert_pattern requires a block to capture errors." unless block_given? begin # TODO: remove after ruby 2.6 dropped yield pass rescue NoMatchingPatternError => e flunk e. end end
#assert_predicate(o1, op, msg = nil)
For testing with predicates. Eg:
assert_predicate str, :empty?
This is really meant for specs and is front-ended by assert_operator:
str.must_be :empty?
#assert_raises(*exp)
Fails unless the block raises one of exp. Returns the exception matched so you can check the message, attributes, etc.
exp takes an optional message on the end to help explain failures and defaults to StandardError if no exception class is passed. Eg:
assert_raises(CustomError) { method_with_custom_error }
With custom error message:
assert_raises(CustomError, 'This should have raised CustomError') { method_with_custom_error }
Using the returned object:
error = assert_raises(CustomError) do
raise CustomError, 'This is really bad'
end
assert_equal 'This is really bad', error.
# File 'lib/minitest/assertions.rb', line 418
def assert_raises *exp flunk "assert_raises requires a block to capture errors." unless block_given? msg = "#{exp.pop}.\n" if String === exp.last exp << StandardError if exp.empty? begin yield rescue *exp => e pass # count assertion return e rescue Minitest::Assertion # incl Skip & UnexpectedError # don't count assertion raise rescue SignalException, SystemExit raise rescue Exception => e flunk proc { exception_details(e, "#{msg}#{mu_pp exp} exception expected, not") } end exp = exp.first if exp.size == 1 flunk "#{msg}#{mu_pp exp} expected but nothing was raised." end
#assert_respond_to(obj, meth, msg = nil, include_all: false)
Fails unless obj responds to meth. include_all defaults to false to match Object#respond_to?
#assert_same(exp, act, msg = nil)
Fails unless exp and act are #equal?
#assert_send(send_ary, m = nil)
send_ary is a receiver, message and arguments.
Fails unless the call returns a true value
#assert_silent
Fails if the block outputs anything to stderr or stdout.
See also: #assert_output
# File 'lib/minitest/assertions.rb', line 488
def assert_silent assert_output "", "" do yield end end
#assert_throws(sym, msg = nil)
Fails unless the block throws sym
# File 'lib/minitest/assertions.rb', line 497
def assert_throws sym, msg = nil default = "Expected #{mu_pp sym} to have been thrown" caught = true value = catch sym do begin yield rescue ThreadError => e # wtf?!? 1.8 + threads == suck default += ", not :#{e.[/uncaught throw \`(\w+?)\'/, 1]}" rescue ArgumentError => e # 1.9 exception raise e unless e..include? "uncaught throw" default += ", not #{e..split(/ /).last}" rescue NameError => e # 1.8 exception raise e unless e.name == sym default += ", not #{e.name.inspect}" end caught = false end assert caught, (msg) { default } value rescue Assertion raise rescue => e raise UnexpectedError, e end
#capture_io
Captures $stdout and $stderr into strings:
out, err = capture_io do
puts "Some info"
warn "You did a bad thing"
end
assert_match %r%info%, out
assert_match %r%bad%, err
NOTE: For efficiency, this method uses StringIO and does not capture IO for subprocesses. Use #capture_subprocess_io for that.
# File 'lib/minitest/assertions.rb', line 538
def capture_io _synchronize do begin captured_stdout, captured_stderr = StringIO.new, StringIO.new orig_stdout, orig_stderr = $stdout, $stderr $stdout, $stderr = captured_stdout, captured_stderr yield return captured_stdout.string, captured_stderr.string ensure $stdout = orig_stdout $stderr = orig_stderr end end end
#capture_subprocess_io
Captures $stdout and $stderr into strings, using Tempfile to ensure that subprocess IO is captured as well.
out, err = capture_subprocess_io do
system "echo Some info"
system "echo You did a bad thing 1>&2"
end
assert_match %r%info%, out
assert_match %r%bad%, err
NOTE: This method is approximately 10x slower than #capture_io so only use it when you need to test the output of a subprocess.
# File 'lib/minitest/assertions.rb', line 571
def capture_subprocess_io _synchronize do begin require "tempfile" captured_stdout, captured_stderr = Tempfile.new("out"), Tempfile.new("err") orig_stdout, orig_stderr = $stdout.dup, $stderr.dup $stdout.reopen captured_stdout $stderr.reopen captured_stderr yield $stdout.rewind $stderr.rewind return captured_stdout.read, captured_stderr.read ensure $stdout.reopen orig_stdout $stderr.reopen orig_stderr orig_stdout.close orig_stderr.close captured_stdout.close! captured_stderr.close! end end end
#diff(exp, act)
Returns a diff between exp and act. If there is no known diff command or if it doesn’t make sense to diff the output (single line, short output), then it simply returns a basic comparison between the two.
See #things_to_diff for more info.
# File 'lib/minitest/assertions.rb', line 57
def diff exp, act result = nil expect, butwas = things_to_diff exp, act return "Expected: #{mu_pp exp}\n Actual: #{mu_pp act}" unless expect Tempfile.open "expect" do |a| a.puts expect a.flush Tempfile.open "butwas" do |b| b.puts butwas b.flush result = `#{Minitest::Assertions.diff} #{a.path} #{b.path}` result.sub!(/^\-\-\- .+/, "--- expected") result.sub!(/^\\\+ .+/, "+++ actual") if result.empty? then klass = exp.class result = [ "No visible difference in the #{klass}#inspect output.\n", "You should look at the implementation of #== on ", "#{klass} or its members.\n", expect, ].join end end end result end
#exception_details(e, msg)
Returns details for exception e
# File 'lib/minitest/assertions.rb', line 603
def exception_details e, msg [ msg, "Class: <#{e.class}>", "Message: <#{e..inspect}>", "---Backtrace---", Minitest.filter_backtrace(e.backtrace), "---------------", ].join "\n" end
#fail_after(y, m, d, msg)
Fails after a given date (in the local time zone). This allows you to put time-bombs in your tests if you need to keep something around until a later date lest you forget about it.
# File 'lib/minitest/assertions.rb', line 619
def fail_after y, m, d, msg flunk msg if Time.now > Time.local(y, m, d) end
#flunk(msg = nil)
Fails with msg.
# File 'lib/minitest/assertions.rb', line 626
def flunk msg = nil msg ||= "Epic Fail!" assert false, msg end
#message(msg = nil, ending = nil, &default)
Returns a proc that will output msg along with the default message.
# File 'lib/minitest/assertions.rb', line 634
def msg = nil, ending = nil, &default proc { msg = msg.call.chomp(".") if Proc === msg = "#{msg}.\n" unless msg.nil? or msg.to_s.empty? "#{}#{default.call}#{ending || "."}" } end
#mu_pp(obj)
This returns a human-readable version of obj. By default #inspect is called. You can override this to use #pretty_inspect if you want.
# File 'lib/minitest/assertions.rb', line 127
def mu_pp obj s = obj.inspect.encode Encoding.default_external return s unless String === obj && (obj.encoding != Encoding.default_external || !obj.valid_encoding?) enc = "# encoding: #{obj.encoding}" val = "# valid: #{obj.valid_encoding?}" [enc, val, s].join "\n" end
#mu_pp_for_diff(obj)
This returns a diff-able more human-readable version of obj. This differs from the regular mu_pp because it expands escaped newlines and makes hex-values (like object_ids) generic. This uses mu_pp to do the first pass and then cleans it up.
# File 'lib/minitest/assertions.rb', line 145
def mu_pp_for_diff obj str = mu_pp obj # both '\n' & '\\n' (_after_ mu_pp (aka inspect)) single = str.match?(/(?<!\\|^)\\n/) double = str.match?(/(?<=\\|^)\\n/) process = if single ^ double then if single then lambda { |s| s == "\\n" ? "\n" : s } # unescape else lambda { |s| s == "\\\\n" ? "\\n\n" : s } # unescape a bit, add nls end else :itself # leave it alone end str .gsub(/\\?\\n/, &process) .gsub(/:0x[a-fA-F0-9]{4,}/m, ":0xXXXXXX") # anonymize hex values end
#pass(_msg = nil)
used for counting assertions
# File 'lib/minitest/assertions.rb', line 645
def pass _msg = nil assert true end
#refute(test, msg = nil)
Fails if test is truthy.
#refute_empty(obj, msg = nil)
Fails if obj is empty.
# File 'lib/minitest/assertions.rb', line 660
def refute_empty obj, msg = nil msg = (msg) { "Expected #{mu_pp obj} to not be empty" } assert_respond_to obj, :empty? refute obj.empty?, msg end
#refute_equal(exp, act, msg = nil)
Fails if exp == act.
For floats use refute_in_delta.
#refute_in_delta(exp, act, delta = 0.001, msg = nil)
For comparing Floats. Fails if exp is within delta of act.
refute_in_delta Math::PI, (22.0 / 7.0)
# File 'lib/minitest/assertions.rb', line 683
def refute_in_delta exp, act, delta = 0.001, msg = nil n = (exp - act).abs msg = (msg) { "Expected |#{exp} - #{act}| (#{n}) to not be <= #{delta}" } refute delta >= n, msg end
#refute_in_epsilon(a, b, epsilon = 0.001, msg = nil)
For comparing Floats. Fails if exp and act have a relative error less than epsilon.
# File 'lib/minitest/assertions.rb', line 695
def refute_in_epsilon a, b, epsilon = 0.001, msg = nil refute_in_delta a, b, a * epsilon, msg end
#refute_includes(collection, obj, msg = nil)
Fails if collection includes obj.
# File 'lib/minitest/assertions.rb', line 702
def refute_includes collection, obj, msg = nil msg = (msg) { "Expected #{mu_pp collection} to not include #{mu_pp obj}" } assert_respond_to collection, :include? refute collection.include?(obj), msg end
#refute_instance_of(cls, obj, msg = nil)
Fails if obj is an instance of cls.
#refute_kind_of(cls, obj, msg = nil)
Fails if obj is a kind of cls.
#refute_match(matcher, obj, msg = nil)
Fails if matcher =~ obj.
# File 'lib/minitest/assertions.rb', line 731
def refute_match matcher, obj, msg = nil msg = (msg) { "Expected #{mu_pp matcher} to not match #{mu_pp obj}" } assert_respond_to matcher, :=~ matcher = Regexp.new Regexp.escape matcher if String === matcher refute matcher =~ obj, msg end
#refute_nil(obj, msg = nil)
Fails if obj is nil.
#refute_operator(o1, op, o2 = UNDEFINED, msg = nil)
Fails if o1 is not op o2. Eg:
refute_operator 1, :>, 2 #=> pass
refute_operator 1, :<, 2 #=> fail
#refute_path_exists(path, msg = nil)
Fails if path exists.
# File 'lib/minitest/assertions.rb', line 785
def refute_path_exists path, msg = nil msg = (msg) { "Expected path '#{path}' to not exist" } refute File.exist?(path), msg end
#refute_pattern
For testing with pattern matching (only supported with Ruby 3.0 and later)
# pass
refute_pattern { [1,2,3] => [String] }
# fail "NoMatchingPatternError expected, but nothing was raised."
refute_pattern { [1,2,3] => [Integer, Integer, Integer] }
This assertion expects a NoMatchingPatternError exception, and will fail if none is raised. Any other exceptions will be raised as normal and generate a test error.
# File 'lib/minitest/assertions.rb', line 758
def refute_pattern raise NotImplementedError, "only available in Ruby 3.0+" unless RUBY_VERSION >= "3.0" flunk "refute_pattern requires a block to capture errors." unless block_given? begin yield flunk "NoMatchingPatternError expected, but nothing was raised." rescue NoMatchingPatternError pass end end
#refute_predicate(o1, op, msg = nil)
For testing with predicates.
refute_predicate str, :empty?
This is really meant for specs and is front-ended by refute_operator:
str.wont_be :empty?
#refute_respond_to(obj, meth, msg = nil, include_all: false)
Fails if obj responds to the message meth. include_all defaults to false to match Object#respond_to?
#refute_same(exp, act, msg = nil)
Fails if exp is the same (by object identity) as act.
#skip(msg = nil, _ignored = nil)
Skips the current run. If run in verbose-mode, the skipped run gets listed at the end of the run but doesn’t cause a failure exit code.
#skip_until(y, m, d, msg)
Skips the current run until a given date (in the local time zone). This allows you to put some fixes on hold until a later date, but still holds you accountable and prevents you from forgetting it.
# File 'lib/minitest/assertions.rb', line 842
def skip_until y, m, d, msg skip msg if Time.now < Time.local(y, m, d) where = caller(1..1).first.rpartition(":in").reject(&:empty?).first warn "Stale skip_until %p at %s" % [msg, where] end
#things_to_diff(exp, act)
Returns things to diff [expect, butwas], or [nil, nil] if nothing to diff.
Criterion:
-
Strings include newlines or escaped newlines, but not both.
-
or: String lengths are > 30 characters.
-
or: Strings are equal to each other (but maybe different encodings?).
-
and: we found a diff executable.
# File 'lib/minitest/assertions.rb', line 102
def things_to_diff exp, act expect = mu_pp_for_diff exp butwas = mu_pp_for_diff act e1, e2 = expect.include?("\n"), expect.include?("\\n") b1, b2 = butwas.include?("\n"), butwas.include?("\\n") need_to_diff = (e1 ^ e2 || b1 ^ b2 || expect.size > 30 || butwas.size > 30 || expect == butwas) && Minitest::Assertions.diff need_to_diff && [expect, butwas] end