-
Notifications
You must be signed in to change notification settings - Fork 0
/
about_to_str.rb
54 lines (42 loc) · 1.31 KB
/
about_to_str.rb
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
require File.expand_path(File.dirname(__FILE__) + '/edgecase')
class AboutToStr < EdgeCase::Koan
class CanNotBeTreatedAsString
def to_s
"non-string-like"
end
end
def test_to_s_returns_a_string_representation
not_like_a_string = CanNotBeTreatedAsString.new
assert_equal __, not_like_a_string.to_s
end
def test_normally_objects_cannot_be_used_where_strings_are_expected
assert_raise(___) do
File.exist?(CanNotBeTreatedAsString.new)
end
end
# ------------------------------------------------------------------
class CanBeTreatedAsString
def to_s
"string-like"
end
def to_str
to_s
end
end
def test_to_str_also_returns_a_string_representation
like_a_string = CanBeTreatedAsString.new
assert_equal __, like_a_string.to_str
end
def test_to_str_allows_objects_to_be_treated_as_strings
assert_equal __, File.exist?(CanBeTreatedAsString.new)
end
# ------------------------------------------------------------------
def acts_like_a_string?(string)
string = string.to_str if string.respond_to?(:to_str)
string.is_a?(String)
end
def test_user_defined_code_can_check_for_to_str
assert_equal __, acts_like_a_string?(CanNotBeTreatedAsString.new)
assert_equal __, acts_like_a_string?(CanBeTreatedAsString.new)
end
end