Module: MiniTest::Assertions

Included in:
Unit::TestCase
Defined in:
lib/minitest/unit.rb

Overview

MiniTest Assertions. All assertion methods accept a msg which is printed if the assertion fails.

Constant Summary collapse

WINDOZE = 
RbConfig::CONFIG['host_os'] =~ /mswin|mingw/

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.diff ⇒ Object

Returns the diff command to use in #diff. Tries to intelligently figure out what diff to use.



69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
 
# File 'lib/minitest/unit.rb', line 69

def self.diff
  @diff = if WINDOZE
            "diff.exe -u"
          else
            if system("gdiff", __FILE__, __FILE__)
              "gdiff -u" # solaris and kin suck
            elsif system("diff", __FILE__, __FILE__)
              "diff -u"
            else
              nil
            end
          end unless defined? @diff

  @diff
end

.diff=(o) ⇒ Object

Set the diff command to use in #diff.



88
89
90
 
# File 'lib/minitest/unit.rb', line 88

def self.diff= o
  @diff = o
end

Instance Method Details

#_assertions ⇒ Object

:nodoc:



167
168
169
 
# File 'lib/minitest/unit.rb', line 167

def _assertions # :nodoc:
  @_assertions ||= 0
end

#_assertions=(n) ⇒ Object

:nodoc:



163
164
165
 
# File 'lib/minitest/unit.rb', line 163

def _assertions= n # :nodoc:
  @_assertions = n
end

#assert(test, msg = nil) ⇒ Object

Fails unless test is a true value.



174
175
176
177
178
179
180
181
182
 
# File 'lib/minitest/unit.rb', line 174

def assert test, msg = nil
  msg ||= "Failed assertion, no message given."
  self._assertions += 1
  unless test then
    msg = msg.call if Proc === msg
    raise MiniTest::Assertion, msg
  end
  true
end

#assert_block(msg = nil) ⇒ Object

Fails unless the block returns a true value.



187
188
189
190
 
# File 'lib/minitest/unit.rb', line 187

def assert_block msg = nil
  msg = message(msg) { "Expected block to return true value" }
  assert yield, msg
end

#assert_empty(obj, msg = nil) ⇒ Object

Fails unless obj is empty.



195
196
197
198
199
 
# File 'lib/minitest/unit.rb', line 195

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

#assert_equal(exp, act, msg = nil) ⇒ Object

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 floats use assert_in_delta.

See also: MiniTest::Assertions.diff



213
214
215
216
 
# File 'lib/minitest/unit.rb', line 213

def assert_equal exp, act, msg = nil
  msg = message(msg, "") { diff exp, act }
  assert(exp == act, msg)
end

#assert_in_delta(exp, act, delta = 0.001, msg = nil) ⇒ Object

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



224
225
226
227
228
 
# File 'lib/minitest/unit.rb', line 224

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

#assert_in_epsilon(a, b, epsilon = 0.001, msg = nil) ⇒ Object

For comparing Floats. Fails unless exp and act have a relative error less than epsilon.



234
235
236
 
# File 'lib/minitest/unit.rb', line 234

def assert_in_epsilon a, b, epsilon = 0.001, msg = nil
  assert_in_delta a, b, [a, b].min * epsilon, msg
end

#assert_includes(collection, obj, msg = nil) ⇒ Object

Fails unless collection includes obj.



241
242
243
244
245
246
247
 
# File 'lib/minitest/unit.rb', line 241

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

#assert_instance_of(cls, obj, msg = nil) ⇒ Object

Fails unless obj is an instace of cls.



252
253
254
255
256
257
258
 
# File 'lib/minitest/unit.rb', line 252

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

#assert_kind_of(cls, obj, msg = nil) ⇒ Object

Fails unless obj is a kind of cls.



263
264
265
266
267
268
 
# File 'lib/minitest/unit.rb', line 263

def assert_kind_of cls, obj, msg = nil # TODO: merge with instance_of
  msg = message(msg) {
    "Expected #{mu_pp(obj)} to be a kind of #{cls}, not #{obj.class}" }

  assert obj.kind_of?(cls), msg
end

#assert_match(exp, act, msg = nil) ⇒ Object

Fails unless exp is =~ act.



273
274
275
276
277
278
 
# File 'lib/minitest/unit.rb', line 273

def assert_match exp, act, msg = nil
  msg = message(msg) { "Expected #{mu_pp(exp)} to match #{mu_pp(act)}" }
  assert_respond_to act, :"=~"
  exp = Regexp.new Regexp.escape exp if String === exp and String === act
  assert exp =~ act, msg
end

#assert_nil(obj, msg = nil) ⇒ Object

Fails unless obj is nil



283
284
285
286
 
# File 'lib/minitest/unit.rb', line 283

def assert_nil obj, msg = nil
  msg = message(msg) { "Expected #{mu_pp(obj)} to be nil" }
  assert obj.nil?, msg
end

#assert_operator(o1, op, o2, msg = nil) ⇒ Object

For testing equality operators and so-forth.

assert_operator 5, :<=, 4



293
294
295
296
 
# File 'lib/minitest/unit.rb', line 293

def assert_operator o1, op, o2, msg = nil
  msg = message(msg) { "Expected #{mu_pp(o1)} to be #{op} #{mu_pp(o2)}" }
  assert o1.__send__(op, o2), msg
end

#assert_output(stdout = nil, stderr = nil) ⇒ Object

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.

See also: #assert_silent



305
306
307
308
309
310
311
312
313
314
 
# File 'lib/minitest/unit.rb', line 305

def assert_output stdout = nil, stderr = nil
  out, err = capture_io do
    yield
  end

  x = assert_equal stdout, out, "In stdout" if stdout
  y = assert_equal stderr, err, "In stderr" if stderr

  (!stdout || x) && (!stderr || y)
end

#assert_raises(*exp) ⇒ Object

Fails unless the block raises one of exp



319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
 
# File 'lib/minitest/unit.rb', line 319

def assert_raises *exp
  msg = "#{exp.pop}\n" if String === exp.last

  should_raise = false
  begin
    yield
    should_raise = true
  rescue MiniTest::Skip => e
    details = "#{msg}#{mu_pp(exp)} exception expected, not"

    if exp.include? MiniTest::Skip then
      return e
    else
      raise e
    end
  rescue Exception => e
    details = "#{msg}#{mu_pp(exp)} exception expected, not"
    assert(exp.any? { |ex|
             ex.instance_of?(Module) ? e.kind_of?(ex) : ex == e.class
           }, exception_details(e, details))

    return e
  end

  exp = exp.first if exp.size == 1
  flunk "#{msg}#{mu_pp(exp)} expected but nothing was raised." if
    should_raise
end

#assert_respond_to(obj, meth, msg = nil) ⇒ Object

Fails unless obj responds to meth.



351
352
353
354
355
356
 
# File 'lib/minitest/unit.rb', line 351

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

#assert_same(exp, act, msg = nil) ⇒ Object

Fails unless exp and act are #equal?



361
362
363
364
365
366
367
 
# File 'lib/minitest/unit.rb', line 361

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

#assert_send(send_ary, m = nil) ⇒ Object

send_ary is a receiver, message and arguments.

Fails unless the call returns a true value TODO: I should prolly remove this from specs



375
376
377
378
379
380
 
# File 'lib/minitest/unit.rb', line 375

def assert_send send_ary, m = nil
  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

#assert_silent ⇒ Object

Fails if the block outputs anything to stderr or stdout.

See also: #assert_output



387
388
389
390
391
 
# File 'lib/minitest/unit.rb', line 387

def assert_silent
  assert_output "", "" do
    yield
  end
end

#assert_throws(sym, msg = nil) ⇒ Object

Fails unless the block throws sym



396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
 
# File 'lib/minitest/unit.rb', line 396

def assert_throws sym, msg = nil
  default = "Expected #{mu_pp(sym)} to have been thrown"
  caught = true
  catch(sym) do
    begin
      yield
    rescue ArgumentError => e     # 1.9 exception
      default += ", not #{e.message.split(/ /).last}"
    rescue NameError => e         # 1.8 exception
      default += ", not #{e.name.inspect}"
    end
    caught = false
  end

  assert caught, message(msg) { default }
end

#capture_io ⇒ Object

Captures $stdout and $stderr into strings:

out, err = capture_io do
  warn "You did a bad thing"
end

assert_match %r%bad%, err



422
423
424
425
426
427
428
429
430
431
432
433
434
435
 
# File 'lib/minitest/unit.rb', line 422

def capture_io
  require 'stringio'

  orig_stdout, orig_stderr         = $stdout, $stderr
  captured_stdout, captured_stderr = StringIO.new, StringIO.new
  $stdout, $stderr                 = captured_stdout, captured_stderr

  yield

  return captured_stdout.string, captured_stderr.string
ensure
  $stdout = orig_stdout
  $stderr = orig_stderr
end

#diff(exp, act) ⇒ Object

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.



98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
 
# File 'lib/minitest/unit.rb', line 98

def diff exp, act
  require "tempfile"

  expect = mu_pp_for_diff exp
  butwas = mu_pp_for_diff act
  result = nil

  need_to_diff =
    MiniTest::Assertions.diff &&
    (expect.include?("\n")    ||
     butwas.include?("\n")    ||
     expect.size > 30         ||
     butwas.size > 30         ||
     expect == butwas)

  return "Expected: #{mu_pp exp}\n  Actual: #{mu_pp act}" unless
    need_to_diff

  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.",
                  "You should look at your implementation of #{klass}#==.",
                  expect
                 ].join "\n"
      end
    end
  end

  result
end

#exception_details(e, msg) ⇒ Object

Returns details for exception e



440
441
442
443
444
445
446
447
448
449
 
# File 'lib/minitest/unit.rb', line 440

def exception_details e, msg
  [
   "#{msg}",
   "Class: <#{e.class}>",
   "Message: <#{e.message.inspect}>",
   "---Backtrace---",
   "#{MiniTest::filter_backtrace(e.backtrace).join("\n")}",
   "---------------",
  ].join "\n"
end

#flunk(msg = nil) ⇒ Object

Fails with msg



454
455
456
457
 
# File 'lib/minitest/unit.rb', line 454

def flunk msg = nil
  msg ||= "Epic Fail!"
  assert false, msg
end

#message(msg = nil, ending = ".", &default) ⇒ Object

Returns a proc that will output msg along with the default message.



462
463
464
465
466
467
 
# File 'lib/minitest/unit.rb', line 462

def message msg = nil, ending = ".", &default
  proc {
    custom_message = "#{msg}.\n" unless msg.nil? or msg.to_s.empty?
    "#{custom_message}#{default.call}#{ending}"
  }
end

#mu_pp(obj) ⇒ Object

This returns a human-readable version of obj. By default #inspect is called. You can override this to use #pretty_print if you want.



147
148
149
150
151
 
# File 'lib/minitest/unit.rb', line 147

def mu_pp obj
  s = obj.inspect
  s = s.encode Encoding.default_external if defined? Encoding
  s
end

#mu_pp_for_diff(obj) ⇒ Object

This returns a diff-able human-readable version of obj. This differs from the regular mu_pp because it expands escaped newlines and makes hex-values generic (like object_ids). This uses mu_pp to do the first pass and then cleans it up.



159
160
161
 
# File 'lib/minitest/unit.rb', line 159

def mu_pp_for_diff obj # TODO: possibly rename
  mu_pp(obj).gsub(/\\n/, "\n").gsub(/0x[a-f0-9]+/m, '0xXXXXXX')
end

#pass(msg = nil) ⇒ Object

used for counting assertions



472
473
474
 
# File 'lib/minitest/unit.rb', line 472

def pass msg = nil
  assert true
end

#refute(test, msg = nil) ⇒ Object

Fails if test is a true value



479
480
481
482
 
# File 'lib/minitest/unit.rb', line 479

def refute test, msg = nil
  msg ||= "Failed refutation, no message given"
  not assert(! test, msg)
end

#refute_empty(obj, msg = nil) ⇒ Object

Fails if obj is empty.



487
488
489
490
491
 
# File 'lib/minitest/unit.rb', line 487

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

#refute_equal(exp, act, msg = nil) ⇒ Object

Fails if exp == act.

For floats use refute_in_delta.



498
499
500
501
502
503
 
# File 'lib/minitest/unit.rb', line 498

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

#refute_in_delta(exp, act, delta = 0.001, msg = nil) ⇒ Object

For comparing Floats. Fails if exp is within delta of act

refute_in_delta Math::PI, (22.0 / 7.0)



510
511
512
513
514
515
516
 
# File 'lib/minitest/unit.rb', line 510

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

#refute_in_epsilon(a, b, epsilon = 0.001, msg = nil) ⇒ Object

For comparing Floats. Fails if exp and act have a relative error less than epsilon.



522
523
524
 
# File 'lib/minitest/unit.rb', line 522

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) ⇒ Object

Fails if collection includes obj



529
530
531
532
533
534
535
 
# File 'lib/minitest/unit.rb', line 529

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

#refute_instance_of(cls, obj, msg = nil) ⇒ Object

Fails if obj is an instance of cls



540
541
542
543
544
545
 
# File 'lib/minitest/unit.rb', line 540

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

#refute_kind_of(cls, obj, msg = nil) ⇒ Object

Fails if obj is a kind of cls



550
551
552
553
 
# File 'lib/minitest/unit.rb', line 550

def refute_kind_of cls, obj, msg = nil # TODO: merge with instance_of
  msg = message(msg) { "Expected #{mu_pp(obj)} to not be a kind of #{cls}" }
  refute obj.kind_of?(cls), msg
end

#refute_match(exp, act, msg = nil) ⇒ Object

Fails if exp =~ act



558
559
560
561
562
563
 
# File 'lib/minitest/unit.rb', line 558

def refute_match exp, act, msg = nil
  msg = message(msg) { "Expected #{mu_pp(exp)} to not match #{mu_pp(act)}" }
  assert_respond_to act, :"=~"
  exp = (/#{Regexp.escape exp}/) if String === exp and String === act
  refute exp =~ act, msg
end

#refute_nil(obj, msg = nil) ⇒ Object

Fails if obj is nil.



568
569
570
571
 
# File 'lib/minitest/unit.rb', line 568

def refute_nil obj, msg = nil
  msg = message(msg) { "Expected #{mu_pp(obj)} to not be nil" }
  refute obj.nil?, msg
end

#refute_operator(o1, op, o2, msg = nil) ⇒ Object

Fails if o1 is not op o2. Eg:

refute_operator 1, :>, 2 #=> pass
refute_operator 1, :<, 2 #=> fail



579
580
581
582
583
584
 
# File 'lib/minitest/unit.rb', line 579

def refute_operator o1, op, o2, msg = nil
  msg = message(msg) {
    "Expected #{mu_pp(o1)} to not be #{op} #{mu_pp(o2)}"
  }
  refute o1.__send__(op, o2), msg
end

#refute_respond_to(obj, meth, msg = nil) ⇒ Object

Fails if obj responds to the message meth.



589
590
591
592
593
 
# File 'lib/minitest/unit.rb', line 589

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

#refute_same(exp, act, msg = nil) ⇒ Object

Fails if exp is the same (by object identity) as act.



598
599
600
601
602
603
604
 
# File 'lib/minitest/unit.rb', line 598

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

#skip(msg = nil, bt = caller) ⇒ Object

Skips the current test. Gets listed at the end of the run but doesn’t cause a failure exit code.

Raises:



610
611
612
613
 
# File 'lib/minitest/unit.rb', line 610

def skip msg = nil, bt = caller
  msg ||= "Skipped, no message given"
  raise MiniTest::Skip, msg, bt
end