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 Minitest::Runnable
for an example.
Returns the diff command to use in diff. Tries to intelligently figure out what diff to use.
# File minitest-5.15.0/lib/minitest/assertions.rb, line 28
def self.diff
return @diff if defined? @diff
@diff = if (RbConfig::CONFIG["host_os"] =~ /mswin|mingw/ &&
system("diff.exe", __FILE__, __FILE__)) then
"diff.exe -u"
elsif system("gdiff", __FILE__, __FILE__)
"gdiff -u" # solaris and kin suck
elsif system("diff", __FILE__, __FILE__)
"diff -u"
else
nil
end
end
Set the diff command to use in diff.
# File minitest-5.15.0/lib/minitest/assertions.rb, line 46
def self.diff= o
@diff = o
end
Fails unless test is truthy.
# File minitest-5.15.0/lib/minitest/assertions.rb, line 177
def assert test, msg = nil
self.assertions += 1
unless test then
msg ||= "Expected #{mu_pp test} to be truthy."
msg = msg.call if Proc === msg
raise Minitest::Assertion, msg
end
true
end
Fails unless obj is empty.
# File minitest-5.15.0/lib/minitest/assertions.rb, line 194
def assert_empty obj, msg = nil
msg = message(msg) { "Expected #{mu_pp(obj)} to be empty" }
assert_respond_to obj, :empty?
assert obj.empty?, msg
end
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 Minitest::Test.make_my_diffs_pretty!
For floats use assert_in_delta.
See also: ::diff
# File minitest-5.15.0/lib/minitest/assertions.rb, line 215
def assert_equal exp, act, msg = nil
msg = message(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
where = Minitest.filter_backtrace(caller).first
where = where.split(/:in /, 2).first # clean up noise
warn "DEPRECATED: Use assert_nil if expecting nil from #{where}. This will fail in Minitest 6."
end
end
result
end
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 minitest-5.15.0/lib/minitest/assertions.rb, line 239
def assert_in_delta exp, act, delta = 0.001, msg = nil
n = (exp - act).abs
msg = message(msg) {
"Expected |#{exp} - #{act}| (#{n}) to be <= #{delta}"
}
assert delta >= n, msg
end
For comparing Floats. Fails unless exp and act
have a relative error less than epsilon.
# File minitest-5.15.0/lib/minitest/assertions.rb, line 251
def assert_in_epsilon exp, act, epsilon = 0.001, msg = nil
assert_in_delta exp, act, [exp.abs, act.abs].min * epsilon, msg
end
Fails unless collection includes obj.
# File minitest-5.15.0/lib/minitest/assertions.rb, line 258
def assert_includes collection, obj, msg = nil
msg = message(msg) {
"Expected #{mu_pp(collection)} to include #{mu_pp(obj)}"
}
assert_respond_to collection, :include?
assert collection.include?(obj), msg
end
Fails unless obj is an instance of cls.
# File minitest-5.15.0/lib/minitest/assertions.rb, line 269
def assert_instance_of cls, obj, msg = nil
msg = message(msg) {
"Expected #{mu_pp(obj)} to be an instance of #{cls}, not #{obj.class}"
}
assert obj.instance_of?(cls), msg
end
Fails unless obj is a kind of cls.
# File minitest-5.15.0/lib/minitest/assertions.rb, line 280
def assert_kind_of cls, obj, msg = nil
msg = message(msg) {
"Expected #{mu_pp(obj)} to be a kind of #{cls}, not #{obj.class}" }
assert obj.kind_of?(cls), msg
end
Fails unless matcher =~ obj.
# File minitest-5.15.0/lib/minitest/assertions.rb, line 290
def assert_match matcher, obj, msg = nil
msg = message(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
end
Assert that the mock verifies correctly.
# File minitest-5.15.0/lib/minitest/mock.rb, line 184
def assert_mock mock
assert mock.verify
end
Fails unless obj is nil
# File minitest-5.15.0/lib/minitest/assertions.rb, line 300
def assert_nil obj, msg = nil
msg = message(msg) { "Expected #{mu_pp(obj)} to be nil" }
assert obj.nil?, msg
end
For testing with binary operators. Eg:
assert_operator 5, :<=, 4
# File minitest-5.15.0/lib/minitest/assertions.rb, line 310
def assert_operator o1, op, o2 = UNDEFINED, msg = nil
return assert_predicate o1, op, msg if UNDEFINED == o2
msg = message(msg) { "Expected #{mu_pp(o1)} to be #{op} #{mu_pp(o2)}" }
assert o1.__send__(op, o2), msg
end
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 minitest-5.15.0/lib/minitest/assertions.rb, line 328
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
Fails unless path exists.
# File minitest-5.15.0/lib/minitest/assertions.rb, line 352
def assert_path_exists path, msg = nil
msg = message(msg) { "Expected path '#{path}' to exist" }
assert File.exist?(path), msg
end
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?
# File minitest-5.15.0/lib/minitest/assertions.rb, line 366
def assert_predicate o1, op, msg = nil
msg = message(msg) { "Expected #{mu_pp(o1)} to be #{op}" }
assert o1.__send__(op), msg
end
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.message
# File minitest-5.15.0/lib/minitest/assertions.rb, line 393
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
Fails unless obj responds to meth.
# File minitest-5.15.0/lib/minitest/assertions.rb, line 424
def assert_respond_to obj, meth, msg = nil
msg = message(msg) {
"Expected #{mu_pp(obj)} (#{obj.class}) to respond to ##{meth}"
}
assert obj.respond_to?(meth), msg
end
Fails unless exp and act are equal?
# File minitest-5.15.0/lib/minitest/assertions.rb, line 434
def assert_same exp, act, msg = nil
msg = message(msg) {
data = [mu_pp(act), act.object_id, mu_pp(exp), exp.object_id]
"Expected %s (oid=%d) to be the same as %s (oid=%d)" % data
}
assert exp.equal?(act), msg
end
send_ary is a receiver, message and arguments.
Fails unless the call returns a true value
# File minitest-5.15.0/lib/minitest/assertions.rb, line 447
def assert_send send_ary, m = nil
where = Minitest.filter_backtrace(caller).first
where = where.split(/:in /, 2).first # clean up noise
warn "DEPRECATED: assert_send. From #{where}"
recv, msg, *args = send_ary
m = message(m) {
"Expected #{mu_pp(recv)}.#{msg}(*#{mu_pp(args)}) to return true" }
assert recv.__send__(msg, *args), m
end
Fails if the block outputs anything to stderr or stdout.
See also: assert_output
# File minitest-5.15.0/lib/minitest/assertions.rb, line 463
def assert_silent
assert_output "", "" do
yield
end
end
Fails unless the block throws sym
# File minitest-5.15.0/lib/minitest/assertions.rb, line 472
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.message[/uncaught throw \`(\w+?)\'/, 1]}"
rescue ArgumentError => e # 1.9 exception
raise e unless e.message.include?("uncaught throw")
default += ", not #{e.message.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, message(msg) { default }
value
rescue Assertion
raise
rescue => e
raise UnexpectedError, e
end
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 minitest-5.15.0/lib/minitest/assertions.rb, line 513
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
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 minitest-5.15.0/lib/minitest/assertions.rb, line 546
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
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 minitest-5.15.0/lib/minitest/assertions.rb, line 58
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 = %x`#{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
Returns details for exception e
# File minitest-5.15.0/lib/minitest/assertions.rb, line 578
def exception_details e, msg
[
"#{msg}",
"Class: <#{e.class}>",
"Message: <#{e.message.inspect}>",
"---Backtrace---",
"#{Minitest.filter_backtrace(e.backtrace).join("\n")}",
"---------------",
].join "\n"
end
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 minitest-5.15.0/lib/minitest/assertions.rb, line 594
def fail_after y,m,d,msg
flunk msg if Time.now > Time.local(y, m, d)
end
Fails with msg.
# File minitest-5.15.0/lib/minitest/assertions.rb, line 601
def flunk msg = nil
msg ||= "Epic Fail!"
assert false, msg
end
Returns a proc that will output msg along with the default
message.
# File minitest-5.15.0/lib/minitest/assertions.rb, line 609
def message msg = nil, ending = nil, &default
proc {
msg = msg.call.chomp(".") if Proc === msg
custom_message = "#{msg}.\n" unless msg.nil? or msg.to_s.empty?
"#{custom_message}#{default.call}#{ending || "."}"
}
end
This returns a human-readable version of obj. By default
inspect is called. You can override this to use pretty_inspect if you want.
See Minitest::Test.make_my_diffs_pretty!
# File minitest-5.15.0/lib/minitest/assertions.rb, line 128
def mu_pp obj
s = obj.inspect
if defined? Encoding then
s = s.encode Encoding.default_external
if String === obj && (obj.encoding != Encoding.default_external ||
!obj.valid_encoding?) then
enc = "# encoding: #{obj.encoding}"
val = "# valid: #{obj.valid_encoding?}"
s = "#{enc}\n#{val}\n#{s}"
end
end
s
end
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 minitest-5.15.0/lib/minitest/assertions.rb, line 151
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
used for counting assertions
# File minitest-5.15.0/lib/minitest/assertions.rb, line 620
def pass _msg = nil
assert true
end
Fails if test is truthy.
# File minitest-5.15.0/lib/minitest/assertions.rb, line 627
def refute test, msg = nil
msg ||= message { "Expected #{mu_pp(test)} to not be truthy" }
assert !test, msg
end
Fails if obj is empty.
# File minitest-5.15.0/lib/minitest/assertions.rb, line 635
def refute_empty obj, msg = nil
msg = message(msg) { "Expected #{mu_pp(obj)} to not be empty" }
assert_respond_to obj, :empty?
refute obj.empty?, msg
end
Fails if exp == act.
For floats use refute_in_delta.
# File minitest-5.15.0/lib/minitest/assertions.rb, line 646
def refute_equal exp, act, msg = nil
msg = message(msg) {
"Expected #{mu_pp(act)} to not be equal to #{mu_pp(exp)}"
}
refute exp == act, msg
end
For comparing Floats. Fails if exp is within
delta of act.
refute_in_delta Math::PI, (22.0 / 7.0)
# File minitest-5.15.0/lib/minitest/assertions.rb, line 658
def refute_in_delta exp, act, delta = 0.001, msg = nil
n = (exp - act).abs
msg = message(msg) {
"Expected |#{exp} - #{act}| (#{n}) to not be <= #{delta}"
}
refute delta >= n, msg
end
For comparing Floats. Fails if exp and act have
a relative error less than epsilon.
# File minitest-5.15.0/lib/minitest/assertions.rb, line 670
def refute_in_epsilon a, b, epsilon = 0.001, msg = nil
refute_in_delta a, b, a * epsilon, msg
end
Fails if collection includes obj.
# File minitest-5.15.0/lib/minitest/assertions.rb, line 677
def refute_includes collection, obj, msg = nil
msg = message(msg) {
"Expected #{mu_pp(collection)} to not include #{mu_pp(obj)}"
}
assert_respond_to collection, :include?
refute collection.include?(obj), msg
end
Fails if obj is an instance of cls.
# File minitest-5.15.0/lib/minitest/assertions.rb, line 688
def refute_instance_of cls, obj, msg = nil
msg = message(msg) {
"Expected #{mu_pp(obj)} to not be an instance of #{cls}"
}
refute obj.instance_of?(cls), msg
end
Fails if obj is a kind of cls.
# File minitest-5.15.0/lib/minitest/assertions.rb, line 698
def refute_kind_of cls, obj, msg = nil
msg = message(msg) { "Expected #{mu_pp(obj)} to not be a kind of #{cls}" }
refute obj.kind_of?(cls), msg
end
Fails if matcher =~ obj.
# File minitest-5.15.0/lib/minitest/assertions.rb, line 706
def refute_match matcher, obj, msg = nil
msg = message(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
Fails if obj is nil.
# File minitest-5.15.0/lib/minitest/assertions.rb, line 716
def refute_nil obj, msg = nil
msg = message(msg) { "Expected #{mu_pp(obj)} to not be nil" }
refute obj.nil?, msg
end
Fails if o1 is not op o2. Eg:
refute_operator 1, :>, 2 #=> pass refute_operator 1, :<, 2 #=> fail
# File minitest-5.15.0/lib/minitest/assertions.rb, line 727
def refute_operator o1, op, o2 = UNDEFINED, msg = nil
return refute_predicate o1, op, msg if UNDEFINED == o2
msg = message(msg) { "Expected #{mu_pp(o1)} to not be #{op} #{mu_pp(o2)}" }
refute o1.__send__(op, o2), msg
end
Fails if path exists.
# File minitest-5.15.0/lib/minitest/assertions.rb, line 736
def refute_path_exists path, msg = nil
msg = message(msg) { "Expected path '#{path}' to not exist" }
refute File.exist?(path), msg
end
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?
# File minitest-5.15.0/lib/minitest/assertions.rb, line 750
def refute_predicate o1, op, msg = nil
msg = message(msg) { "Expected #{mu_pp(o1)} to not be #{op}" }
refute o1.__send__(op), msg
end
Fails if obj responds to the message meth.
# File minitest-5.15.0/lib/minitest/assertions.rb, line 758
def refute_respond_to obj, meth, msg = nil
msg = message(msg) { "Expected #{mu_pp(obj)} to not respond to #{meth}" }
refute obj.respond_to?(meth), msg
end
Fails if exp is the same (by object identity) as
act.
# File minitest-5.15.0/lib/minitest/assertions.rb, line 767
def refute_same exp, act, msg = nil
msg = message(msg) {
data = [mu_pp(act), act.object_id, mu_pp(exp), exp.object_id]
"Expected %s (oid=%d) to not be the same as %s (oid=%d)" % data
}
refute exp.equal?(act), msg
end
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.
# File minitest-5.15.0/lib/minitest/assertions.rb, line 780
def skip msg = nil, bt = caller
msg ||= "Skipped, no message given"
@skip = true
raise Minitest::Skip, msg, bt
end
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 minitest-5.15.0/lib/minitest/assertions.rb, line 792
def skip_until y,m,d,msg
skip msg if Time.now < Time.local(y, m, d)
where = caller.first.rpartition(':in').reject(&:empty?).first
warn "Stale skip_until %p at %s" % [msg, where]
end
Was this testcase skipped? Meant for teardown.
# File minitest-5.15.0/lib/minitest/assertions.rb, line 801
def skipped?
defined?(@skip) and @skip
end
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 minitest-5.15.0/lib/minitest/assertions.rb, line 103
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