| Module | Shoulda::Macros |
| In: |
lib/shoulda/macros.rb
|
Macro that creates a test asserting a change between the return value of a block that is run before and after the current setup block is run. This is similar to Active Support‘s assert_difference assertion, but supports more than just numeric values. See also should_not_change.
The passed description will be used when generating the test name and failure messages.
Example:
context "Creating a post" do
setup { Post.create }
should_change("the number of posts", :by => 1) { Post.count }
end
As shown in this example, the :by option expects a numeric difference between the before and after values of the expression. You may also specify :from and :to options:
should_change("the number of posts", :from => 0, :to => 1) { Post.count }
should_change("the post title", :from => "old", :to => "new") { @post.title }
Combinations of :by, :from, and :to are allowed:
# Assert the value changed in some way:
should_change("the post title") { @post.title }
# Assert the value changed to anything other than "old:"
should_change("the post title", :from => "old") { @post.title }
# Assert the value changed to "new:"
should_change("the post title", :to => "new") { @post.title }
# File lib/shoulda/macros.rb, line 37
37: def should_change(description, options = {}, &block)
38: by, from, to = get_options!([options], :by, :from, :to)
39: stmt = "change #{description}"
40: stmt << " from #{from.inspect}" if from
41: stmt << " to #{to.inspect}" if to
42: stmt << " by #{by.inspect}" if by
43:
44: if block_given?
45: code = block
46: else
47: warn "[DEPRECATION] should_change(expression, options) is deprecated. " <<
48: "Use should_change(description, options) { code } instead."
49: code = lambda { eval(description) }
50: end
51: before = lambda { @_before_should_change = code.bind(self).call }
52: should stmt, :before => before do
53: old_value = @_before_should_change
54: new_value = code.bind(self).call
55: assert_operator from, :===, old_value, "#{description} did not originally match #{from.inspect}" if from
56: assert_not_equal old_value, new_value, "#{description} did not change" unless by == 0
57: assert_operator to, :===, new_value, "#{description} was not changed to match #{to.inspect}" if to
58: assert_equal old_value + by, new_value if by
59: end
60: end
Macro that creates a test asserting that a record of the given class was created.
Example:
context "creating a post" do
setup { Post.create(post_attributes) }
should_create :post
end
# File lib/shoulda/macros.rb, line 98
98: def should_create(class_name)
99: should_change_record_count_of(class_name, 1, 'create')
100: end
Macro that creates a test asserting that a record of the given class was destroyed.
Example:
context "destroying a post" do
setup { Post.first.destroy }
should_destroy :post
end
# File lib/shoulda/macros.rb, line 111
111: def should_destroy(class_name)
112: should_change_record_count_of(class_name, -1, 'destroy')
113: end
Macro that creates a test asserting no change between the return value of a block that is run before and after the current setup block is run. This is the logical opposite of should_change.
The passed description will be used when generating the test name and failure message.
Example:
context "Updating a post" do
setup { @post.update_attributes(:title => "new") }
should_not_change("the number of posts") { Post.count }
end
# File lib/shoulda/macros.rb, line 74
74: def should_not_change(description, &block)
75: if block_given?
76: code = block
77: else
78: warn "[DEPRECATION] should_not_change(expression) is deprecated. " <<
79: "Use should_not_change(description) { code } instead."
80: code = lambda { eval(description) }
81: end
82: before = lambda { @_before_should_not_change = code.bind(self).call }
83: should "not change #{description}", :before => before do
84: new_value = code.bind(self).call
85: assert_equal @_before_should_not_change, new_value, "#{description} changed"
86: end
87: end