summaryrefslogtreecommitdiff
path: root/spec/ruby/core/module/refine_spec.rb
blob: 67832ff6769db015e6100c09a3a9cb53629f73d8 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
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
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
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
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619

return ## this code causes double free and now we are debugging.

require File.expand_path('../../../spec_helper', __FILE__)
require File.expand_path('../fixtures/refine', __FILE__)

describe "Module#refine" do
  it "runs its block in an anonymous module" do
    inner_self = nil
    mod = Module.new do
      refine String do
        inner_self = self
      end
    end

    mod.should_not == inner_self
    inner_self.should be_kind_of(Module)
    inner_self.name.should == nil
  end

  it "uses the same anonymous module for future refines of the same class" do
    selves = []
    mod = Module.new do
      refine String do
        selves << self
      end
    end

    mod.module_eval do
      refine String do
        selves << self
      end
    end

    selves[0].should == selves[1]
  end

  it "adds methods defined in its block to the anonymous module's public instance methods" do
    inner_self = nil
    mod = Module.new do
      refine String do
        def blah
          "blah"
        end
        inner_self = self
      end
    end

    inner_self.public_instance_methods.should include(:blah)
  end

  it "returns created anonymous module" do
    inner_self = nil
    result = nil
    mod = Module.new do
      result = refine String do
        inner_self = self
      end
    end

    result.should == inner_self
  end

  it "raises ArgumentError if not passed an argument" do
    lambda do
      Module.new do
        refine {}
      end
    end.should raise_error(ArgumentError)
  end

  it "raises TypeError if not passed a class" do
    lambda do
      Module.new do
        refine("foo") {}
      end
    end.should raise_error(TypeError)
  end

  ruby_version_is "" ... "2.4" do
    it "raises TypeError if passed a module" do
      lambda do
        Module.new do
          refine(Enumerable) {}
        end
      end.should raise_error(TypeError)
    end
  end

  ruby_version_is "2.4" do
    it "accepts a module as argument" do
      inner_self = nil
      Module.new do
        refine(Enumerable) do
          def blah
          end
          inner_self = self
        end
      end

      inner_self.public_instance_methods.should include(:blah)
    end
  end

  it "raises ArgumentError if not given a block" do
    lambda do
      Module.new do
        refine String
      end
    end.should raise_error(ArgumentError)
  end

  it "applies refinements to calls in the refine block" do
    result = nil
    Module.new do
      refine(String) do
        def foo; "foo"; end
        result = "hello".foo
      end
    end
    result.should == "foo"
  end

  it "doesn't apply refinements outside the refine block" do
    Module.new do
      refine(String) {def foo; "foo"; end}
      -> () {
        "hello".foo
      }.should raise_error(NoMethodError)
    end
  end

  it "does not apply refinements to external scopes not using the module" do
    Module.new do
      refine(String) {def foo; 'foo'; end}
    end

    lambda {"hello".foo}.should raise_error(NoMethodError)
  end

  # When defining multiple refinements in the same module,
  # inside a refine block all refinements from the same
  # module are active when a refined method is called
  it "makes available all refinements from the same module" do
    refinement = Module.new do
      refine Integer do
        def to_json_format
          to_s
        end
      end

      refine Array do
        def to_json_format
          "[" + map { |i| i.to_json_format }.join(", ") + "]"
        end
      end

      refine Hash do
        def to_json_format
          "{" + map { |k, v| k.to_s.dump + ": " + v.to_json_format }.join(", ") + "}"
        end
      end
    end

    result = nil

    Module.new do
      using refinement

      result = [{1 => 2}, {3 => 4}].to_json_format
    end

    result.should == '[{"1": 2}, {"3": 4}]'
  end

  it "does not make available methods from another refinement module" do
    refinery_integer = Module.new do
      refine Integer do
        def to_json_format
          to_s
        end
      end
    end

    refinery_array = Module.new do
      refine Array do
        def to_json_format
          "[" + map { |i| i.to_json_format }.join(",") + "]"
        end
      end
    end

    result = nil

    -> () {
      Module.new do
        using refinery_integer
        using refinery_array

        [1, 2].to_json_format
      end
    }.should raise_error(NoMethodError)
  end

  # method lookup:
  #   * The prepended modules from the refinement for C
  #   * The refinement for C
  #   * The included modules from the refinement for C
  #   * The prepended modules of C
  #   * C
  #   * The included modules of C
  describe "method lookup" do
    it "looks in the object singleton class first" do
      refinement = Module.new do
        refine ModuleSpecs::ClassWithFoo  do
          def foo; "foo from refinement"; end
        end
      end

      result = nil
      Module.new do
        using refinement

        obj = ModuleSpecs::ClassWithFoo.new
        class << obj
          def foo; "foo from singleton class"; end
        end
        result = obj.foo
      end

      result.should == "foo from singleton class"
    end

    it "looks in prepended modules from the refinement first" do
      refinement = Module.new do
        refine ModuleSpecs::ClassWithFoo  do
          include ModuleSpecs::IncludedModule
          prepend ModuleSpecs::PrependedModule

          def foo; "foo from refinement"; end
        end
      end

      result = nil
      Module.new do
        using refinement
        result = ModuleSpecs::ClassWithFoo.new.foo
      end

      result.should == "foo from prepended module"
    end

    it "looks in refinement then" do
      refinement = Module.new do
        refine(ModuleSpecs::ClassWithFoo) do
          include ModuleSpecs::IncludedModule

          def foo; "foo from refinement"; end
        end
      end

      result = nil
      Module.new do
        using refinement
        result = ModuleSpecs::ClassWithFoo.new.foo
      end

      result.should == "foo from refinement"
    end

    it "looks in included modules from the refinement then" do
      refinement = Module.new do
        refine ModuleSpecs::ClassWithFoo  do
          include ModuleSpecs::IncludedModule
        end
      end

      result = nil
      Module.new do
        using refinement
        result = ModuleSpecs::ClassWithFoo.new.foo
      end

      result.should == "foo from included module"
    end

    it "looks in the class then" do
      refinement = Module.new do
        refine(ModuleSpecs::ClassWithFoo) { }
      end

      result = nil
      Module.new do
        using refinement
        result = ModuleSpecs::ClassWithFoo.new.foo
      end

      result.should == "foo"
    end
  end


  # methods in a subclass have priority over refinements in a superclass
  it "does not override methods in subclasses" do
    subclass = Class.new(ModuleSpecs::ClassWithFoo) do
      def foo; "foo from subclass"; end
    end

    refinement = Module.new do
      refine ModuleSpecs::ClassWithFoo do
        def foo; "foo from refinement"; end
      end
    end

    result = nil
    Module.new do
      using refinement
      result = subclass.new.foo
    end

    result.should == "foo from subclass"
  end

  context "for methods accesses indirectly" do
    ruby_version_is "" ... "2.4" do
      it "is not honored by Kernel#send" do
        refinement = Module.new do
          refine ModuleSpecs::ClassWithFoo do
            def foo; "foo from refinement"; end
          end
        end

        result = nil
        Module.new do
          using refinement
          result = ModuleSpecs::ClassWithFoo.new.send :foo
        end

        result.should == "foo"
      end

      it "is not honored by BasicObject#__send__" do
        refinement = Module.new do
          refine ModuleSpecs::ClassWithFoo do
            def foo; "foo from refinement"; end
          end
        end

        result = nil
        Module.new do
          using refinement
          result = ModuleSpecs::ClassWithFoo.new.__send__ :foo
        end

        result.should == "foo"
      end

      it "is not honored by Symbol#to_proc" do
        refinement = Module.new do
          refine Integer do
            def to_s
              "(#{super})"
            end
          end
        end

        result = nil
        Module.new do
          using refinement
          result = [1, 2, 3].map(&:to_s)
        end

        result.should == ["1", "2", "3"]
      end
    end

    ruby_version_is "2.4" do
      it "is honored by Kernel#send" do
        refinement = Module.new do
          refine ModuleSpecs::ClassWithFoo do
            def foo; "foo from refinement"; end
          end
        end

        result = nil
        Module.new do
          using refinement
          result = ModuleSpecs::ClassWithFoo.new.send :foo
        end

        result.should == "foo from refinement"
      end

      it "is honored by BasicObject#__send__" do
        refinement = Module.new do
          refine ModuleSpecs::ClassWithFoo do
            def foo; "foo from refinement"; end
          end
        end

        result = nil
        Module.new do
          using refinement
          result = ModuleSpecs::ClassWithFoo.new.__send__ :foo
        end

        result.should == "foo from refinement"
      end

      it "is honored by Symbol#to_proc" do
        refinement = Module.new do
          refine Integer do
            def to_s
              "(#{super})"
            end
          end
        end

        result = nil
        Module.new do
          using refinement
          result = [1, 2, 3].map(&:to_s)
        end

        result.should == ["(1)", "(2)", "(3)"]
      end
    end

    it "is honored by Kernel#binding" do
      refinement = Module.new do
        refine String do
          def to_s
            "hello from refinement"
          end
        end
      end

      klass = Class.new do
        using refinement

        def foo
          "foo".to_s
        end

        def get_binding
          binding
        end
      end

      result = Kernel.eval("self.foo()", klass.new.get_binding)
      result.should == "hello from refinement"
    end

    it "is not honored by Kernel#method" do
      klass = Class.new
      refinement = Module.new do
        refine klass do
          def foo; end
        end
      end

      -> {
        Module.new do
          using refinement
          klass.new.method(:foo)
        end
      }.should raise_error(NameError, /undefined method `foo'/)
    end

    it "is not honored by Kernel#respond_to?" do
      klass = Class.new
      refinement = Module.new do
        refine klass do
          def foo; end
        end
      end

      result = nil
      Module.new do
        using refinement
        result = klass.new.respond_to?(:foo)
      end

      result.should == false
    end
  end

  context "when super is called in a refinement" do
    it "looks in the included to refinery module" do
      refinement = Module.new do
        refine ModuleSpecs::ClassWithFoo  do
          include ModuleSpecs::IncludedModule

          def foo
            super
          end
        end
      end

      result = nil
      Module.new do
        using refinement
        result = ModuleSpecs::ClassWithFoo.new.foo
      end

      result.should == "foo from included module"
    end

    it "looks in the refined class" do
      refinement = Module.new do
        refine ModuleSpecs::ClassWithFoo  do
          def foo
            super
          end
        end
      end

      result = nil
      Module.new do
        using refinement
        result = ModuleSpecs::ClassWithFoo.new.foo
      end

      result.should == "foo"
    end

    # super in a method of a refinement invokes the method in the refined
    # class even if there is another refinement which has been activated
    # in the same context.
    it "looks in the refined class even if there is another active refinement" do
      refinement = Module.new do
        refine ModuleSpecs::ClassWithFoo  do
          def foo
            "foo from refinement"
          end
        end
      end

      refinement_with_super = Module.new do
        refine ModuleSpecs::ClassWithFoo  do
          def foo
            super
          end
        end
      end

      result = nil
      Module.new do
        using refinement
        using refinement_with_super
        result = ModuleSpecs::ClassWithFoo.new.foo
      end

      result.should == "foo"
    end
  end

  # Refinements are inherited by module inclusion.
  # That is, using activates all refinements in the ancestors of the specified module.
  # Refinements in a descendant have priority over refinements in an ancestor.
  context "module inclusion" do
    it "activates all refinements from all ancestors" do
      refinement_included = Module.new do
        refine Integer do
          def to_json_format
            to_s
          end
        end
      end

      refinement = Module.new do
        include refinement_included

        refine Array do
          def to_json_format
            "[" + map { |i| i.to_s }.join(", ") + "]"
          end
        end
      end

      result = nil
      Module.new do
        using refinement
        result = [5.to_json_format, [1, 2, 3].to_json_format]
      end

      result.should == ["5", "[1, 2, 3]"]
    end

    it "overrides methods of ancestors by methods in descendants" do
      refinement_included = Module.new do
        refine Integer do
          def to_json_format
            to_s
          end
        end
      end

      refinement = Module.new do
        include refinement_included

        refine Integer do
          def to_json_format
            "hello from refinement"
          end
        end
      end

      result = nil
      Module.new do
        using refinement
        result = 5.to_json_format
      end

      result.should == "hello from refinement"
    end
  end
end