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
|
Feature: Defining a matcher supporting block expectations
When you wish to support block expectations (e.g. `expect { ... }.to matcher`) with
your custom matchers you must specify this. You can do this manually (or determinately
based on some logic) by defining a `supports_block_expectation?` method or by using
the DSL's `supports_block_expectations` shortcut method.
Scenario: Define a block matcher manually
Given a file named "block_matcher_spec.rb" with:
"""ruby
RSpec::Matchers.define :support_blocks do
match do |actual|
actual.is_a? Proc
end
def supports_block_expectations?
true # or some logic
end
end
RSpec.describe "a custom block matcher" do
specify { expect { }.to support_blocks }
end
"""
When I run `rspec ./block_matcher_spec.rb`
Then the example should pass
Scenario: Define a block matcher using shortcut
Given a file named "block_matcher_spec.rb" with:
"""ruby
RSpec::Matchers.define :support_blocks do
match do |actual|
actual.is_a? Proc
end
supports_block_expectations
end
RSpec.describe "a custom block matcher" do
specify { expect { }.to support_blocks }
end
"""
When I run `rspec ./block_matcher_spec.rb`
Then the example should pass
Scenario: Define a block matcher using shortcut
Given a file named "block_matcher_spec.rb" with:
"""ruby
RSpec::Matchers.define :support_blocks_with_errors do
match(:notify_expectation_failures => true) do |actual|
actual.call
true
end
supports_block_expectations
end
RSpec.describe "a custom block matcher" do
specify do
expect {
expect(true).to eq false
}.to support_blocks_with_errors
end
end
"""
When I run `rspec ./block_matcher_spec.rb`
Then it should fail with:
"""
Failures:
1) a custom block matcher is expected to support blocks with errors
Failure/Error: expect(true).to eq false
expected: false
got: true
(compared using ==)
"""
|
