-
Notifications
You must be signed in to change notification settings - Fork 0
/
about_nil.rb
38 lines (32 loc) · 1.03 KB
/
about_nil.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
require File.expand_path(File.dirname(__FILE__) + '/edgecase')
class AboutNil < EdgeCase::Koan
def test_nil_is_an_object
assert_equal true, nil.is_a?(Object), "Unlike NULL in other languages"
end
def test_you_dont_get_null_pointer_errors_when_calling_methods_on_nil
# What happens when you call a method that doesn't exist. The
# following begin/rescue/end code block captures the exception and
# make some assertions about it.
begin
nil.some_method_nil_doesnt_know_about
rescue Exception => ex
# What exception has been caught?
assert_equal NoMethodError, ex.class
# What message was attached to the exception?
# (HINT: replace __ with part of the error message.)
assert_match(/nil/, ex.message)
end
end
def test_nil_has_a_few_methods_defined_on_it
assert_equal true, nil.nil?
assert_equal "", nil.to_s
assert_equal "nil", nil.inspect
# THINK ABOUT IT:
#
# Is it better to use
# obj.nil?
# or
# obj == nil
# Why?
end
end