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
|
require File.expand_path('../../../spec_helper', __FILE__)
require 'set'
ruby_version_is '2.4' do
describe "Set#compare_by_identity" do
it "compares its members by identity" do
a = "a"
b1 = "b"
b2 = "b"
set = Set.new
set.compare_by_identity
set.merge([a, a, b1, b2])
set.to_a.sort.should == [a, b1, b2].sort
end
it "causes future comparisons on the receiver to be made by identity" do
elt = [1]
set = Set.new
set << elt
set.member?(elt.dup).should be_true
set.compare_by_identity
set.member?(elt.dup).should be_false
end
it "rehashes internally so that old members can be looked up" do
set = Set.new
(1..10).each { |k| set << k }
o = Object.new
def o.hash; 123; end
set << o
set.compare_by_identity
set.member?(o).should be_true
end
it "returns self" do
set = Set.new
result = set.compare_by_identity
result.should equal(set)
end
it "is idempotent and has no effect on an already compare_by_identity set" do
set = Set.new.compare_by_identity
set << :foo
set.compare_by_identity.should equal(set)
set.compare_by_identity?.should == true
set.to_a.should == [:foo]
end
it "uses the semantics of BasicObject#equal? to determine members identity" do
:a.equal?(:a).should == true
Set.new.compare_by_identity.merge([:a, :a]).to_a.should == [:a]
ary1 = [1]
ary2 = [1]
ary1.equal?(ary2).should == false
Set.new.compare_by_identity.merge([ary1, ary2]).to_a.sort.should == [ary1, ary2].sort
end
it "uses #equal? semantics, but doesn't actually call #equal? to determine identity" do
set = Set.new.compare_by_identity
obj = mock("equal")
obj.should_not_receive(:equal?)
set << :foo
set << obj
set.to_a.should == [:foo, obj]
end
it "does not call #hash on members" do
elt = mock("element")
elt.should_not_receive(:hash)
set = Set.new.compare_by_identity
set << elt
set.member?(elt).should be_true
end
it "regards #dup'd objects as having different identities" do
a1 = "a"
a2 = a1.dup
set = Set.new.compare_by_identity
set.merge([a1, a2])
set.to_a.sort.should == [a1, a2].sort
end
it "regards #clone'd objects as having different identities" do
a1 = "a"
a2 = a1.clone
set = Set.new.compare_by_identity
set.merge([a1, a2])
set.to_a.sort.should == [a1, a2].sort
end
it "raises a RuntimeError on frozen sets" do
set = Set.new.freeze
lambda {
set.compare_by_identity
}.should raise_error(RuntimeError, /frozen Hash/)
end
it "persists over #dups" do
set = Set.new.compare_by_identity
set << :a
set_dup = set.dup
set_dup.should == set
set_dup << :a
set_dup.to_a.should == [:a]
end
it "persists over #clones" do
set = Set.new.compare_by_identity
set << :a
set_clone = set.clone
set_clone.should == set
set_clone << :a
set_clone.to_a.should == [:a]
end
it "is not equal to set what does not compare by identity" do
Set.new([1, 2]).should == Set.new([1, 2])
Set.new([1, 2]).should_not == Set.new([1, 2]).compare_by_identity
end
end
end
ruby_version_is '2.4' do
describe "Set#compare_by_identity?" do
it "returns false by default" do
Set.new.compare_by_identity?.should == false
end
it "returns true once #compare_by_identity has been invoked on self" do
set = Set.new
set.compare_by_identity
set.compare_by_identity?.should == true
end
it "returns true when called multiple times on the same set" do
set = Set.new
set.compare_by_identity
set.compare_by_identity?.should == true
set.compare_by_identity?.should == true
set.compare_by_identity?.should == true
end
end
end
|