1module Spec
2 module Matchers
3
4 class Be #:nodoc:
5 def initialize(*args)
6 if args.empty?
7 @expected = :satisfy_if
8 else
9 @expected = parse_expected(args.shift)
10 end
11 @args = args
12 @comparison = ""
13 end
14
15 def matches?(actual)
16 @actual = actual
17 if handling_predicate?
18 begin
19 return @result = actual.__send__(predicate, *@args)
20 rescue => predicate_error
21 # This clause should be empty, but rcov will not report it as covered
22 # unless something (anything) is executed within the clause
23 rcov_error_report = "http://eigenclass.org/hiki.rb?rcov-0.8.0"
24 end
25
26 # This supports should_exist > target.exists? in the old world.
27 # We should consider deprecating that ability as in the new world
28 # you can't write "should exist" unless you have your own custom matcher.
29 begin
30 return @result = actual.__send__(present_tense_predicate, *@args)
31 rescue
32 raise predicate_error
33 end
34 else
35 return match_or_compare
36 end
37 end
38
39 def failure_message
40 return "expected #{@comparison}#{expected}, got #{@actual.inspect}" unless handling_predicate?
41 return "expected #{predicate}#{args_to_s} to return true, got #{@result.inspect}"
42 end
43
44 def negative_failure_message
45 return "expected not #{expected}, got #{@actual.inspect}" unless handling_predicate?
46 return "expected #{predicate}#{args_to_s} to return false, got #{@result.inspect}"
47 end
48
49 def expected
50 return "if to be satisfied" if @expected == :satisfy_if
51 return true if @expected == :true
52 return false if @expected == :false
53 return "nil" if @expected == :nil
54 return @expected.inspect
55 end
56
57 def match_or_compare
58 return @actual ? true : false if @expected == :satisfy_if
59 return @actual == true if @expected == :true
60 return @actual == false if @expected == :false
61 return @actual.nil? if @expected == :nil
62 return @actual < @expected if @less_than
63 return @actual <= @expected if @less_than_or_equal
64 return @actual >= @expected if @greater_than_or_equal
65 return @actual > @expected if @greater_than
66 return @actual == @expected if @double_equal
67 return @actual === @expected if @triple_equal
68 return @actual.equal?(@expected)
69 end
70
71 def ==(expected)
72 @prefix = "be "
73 @double_equal = true
74 @comparison = "== "
75 @expected = expected
76 self
77 end
78
79 def ===(expected)
80 @prefix = "be "
81 @triple_equal = true
82 @comparison = "=== "
83 @expected = expected
84 self
85 end
86
87 def <(expected)
88 @prefix = "be "
89 @less_than = true
90 @comparison = "< "
91 @expected = expected
92 self
93 end
94
95 def <=(expected)
96 @prefix = "be "
97 @less_than_or_equal = true
98 @comparison = "<= "
99 @expected = expected
100 self
101 end
102
103 def >=(expected)
104 @prefix = "be "
105 @greater_than_or_equal = true
106 @comparison = ">= "
107 @expected = expected
108 self
109 end
110
111 def >(expected)
112 @prefix = "be "
113 @greater_than = true
114 @comparison = "> "
115 @expected = expected
116 self
117 end
118
119 def description
120 "#{prefix_to_sentence}#{comparison}#{expected_to_sentence}#{args_to_sentence}"
121 end
122
123 private
124 def parse_expected(expected)
125 if Symbol === expected
126 @handling_predicate = true
127 ["be_an_","be_a_","be_"].each do |prefix|
128 if expected.starts_with?(prefix)
129 @prefix = prefix
130 return "#{expected.to_s.sub(@prefix,"")}".to_sym
131 end
132 end
133 end
134 @prefix = ""
135 return expected
136 end
137
138 def handling_predicate?
139 return false if [:true, :false, :nil].include?(@expected)
140 return @handling_predicate
141 end
142
143 def predicate
144 "#{@expected.to_s}?".to_sym
145 end
146
147 def present_tense_predicate
148 "#{@expected.to_s}s?".to_sym
149 end
150
151 def args_to_s
152 return "" if @args.empty?
153 inspected_args = @args.collect{|a| a.inspect}
154 return "(#{inspected_args.join(', ')})"
155 end
156
157 def comparison
158 @comparison
159 end
160
161 def expected_to_sentence
162 split_words(@expected)
163 end
164
165 def prefix_to_sentence
166 split_words(@prefix)
167 end
168
169 def split_words(sym)
170 sym.to_s.gsub(/_/,' ')
171 end
172
173 def args_to_sentence
174 case @args.length
175 when 0
176 ""
177 when 1
178 " #{@args[0]}"
179 else
180 " #{@args[0...-1].join(', ')} and #{@args[-1]}"
181 end
182 end
183
184 end
185
186 # :call-seq:
187 # should be
188 # should be_true
189 # should be_false
190 # should be_nil
191 # should be_arbitrary_predicate(*args)
192 # should_not be_nil
193 # should_not be_arbitrary_predicate(*args)
194 #
195 # Given true, false, or nil, will pass if actual is
196 # true, false or nil (respectively). Given no args means
197 # the caller should satisfy an if condition (to be or not to be).
198 #
199 # Predicates are any Ruby method that ends in a "?" and returns true or false.
200 # Given be_ followed by arbitrary_predicate (without the "?"), RSpec will match
201 # convert that into a query against the target object.
202 #
203 # The arbitrary_predicate feature will handle any predicate
204 # prefixed with "be_an_" (e.g. be_an_instance_of), "be_a_" (e.g. be_a_kind_of)
205 # or "be_" (e.g. be_empty), letting you choose the prefix that best suits the predicate.
206 #
207 # == Examples
208 #
209 # target.should be
210 # target.should be_true
211 # target.should be_false
212 # target.should be_nil
213 # target.should_not be_nil
214 #
215 # collection.should be_empty #passes if target.empty?
216 # "this string".should be_an_intance_of(String)
217 #
218 # target.should_not be_empty #passes unless target.empty?
219 # target.should_not be_old_enough(16) #passes unless target.old_enough?(16)
220 def be(*args)
221 Matchers::Be.new(*args)
222 end
223 end
224end