Provides a set of helper methods around Minitest's Object#stub
method.
The following methods are available:
.stub_with_args
- Stubs a class method for the duration of the block.
- If the method is called, asserts that it is called with the expected arguments.
- Doesn't mind how many times the method is called, if at all.
.stub_and_expect
- Stubs a class method for the duration of the block.
- Asserts that the method is called the exact amount of times as expected, and with the expected arguments.
Add this line to your application's Gemfile:
gem "minitest-stub_on_roids"
And then execute:
$ bundle
Or install it yourself as:
$ gem install minitest-stub_on_roids
Require minitest/stub_on_roids
in your test:
require 'minitest/stub_on_roids'
Extend the class you want to stub methods of:
Banana.extend Minitest::StubOnRoids
This will add the following methods to the class:
Use .stub_with_args
to stub a class method as you normally would but also assert that if it is called - it is called with the expected arguments:
Banana.stub_with_args(:new, banana_mock, [3.0, "Yellow"]) do
Banana.new(3.0, "Yellow")
end
# :new is stubbed and `banana_mock` is returned instead
Banana.stub_with_args(:new, banana_mock, [3.0, "Green"]) do
Banana.new(3.0, "Yellow")
end
# A StubbedMethodArgsError is raised because :new was called with the wrong arguments
Just like with Minitest's Object#stub
method, there is no expectation on the amount of times the stubbed method is called in the block.
Use .stub_and_expect
to stub a class method as you normally would but also set expectations on it, similarly to using Minitest::Mock#expect
.
This means that a MockExpectationError
will be raised if within the block...
- The method is called with a different set of arguments than expected.
- The method is called more or less the amount of times it was expected to be called.
Banana.stub_and_expect(:new, banana_mock, [3.0, "Yellow"]) do
# Not calling `Banana.new`
end
# => MockExpectationError raised
Banana.stub_and_expect(:new, banana_mock, [3.0, "Yellow"]) do
Banana.new(3.0, "Yellow")
Banana.new(3.0, "Yellow")
end
# => MockExpectationError raised
Use the times
keyword argument to expect a method to be called multiple times within the block (default is 1):
Banana.stub_and_expect(:new, banana_mock, [3.0, "Yellow"], times: 2) do
Banana.new(3.0, "Yellow")
Banana.new(3.0, "Yellow")
end
# => Works
Use the expectations
keyword argument to expect a method to be called a multiple times within the block with different arguments and return values (order must be respected).
Given the following expectations array:
expectations = [
{
expected_args: [3.0, "Yellow"],
return_value: banana_mock
},
{
expected_args: [5.0, "Green"],
return_value: banana_mock2
},
{
expected_args: [15.0, "Red"],
return_value: banana_mock3
}
]
Calling Banana.new
multiple times exactly as expected works:
Banana.stub_and_expect(:new, expectations: expectations) do
Banana.new(3.0, "Yellow")
Banana.new(5.0, "Green")
Banana.new(15.0, "Red")
end
# => Works
Calling Banana.new
with the wrong arguments fails:
Banana.stub_and_expect(:new, expectations: expectations) do
Banana.new(3.0, "Yellow")
Banana.new(15.0, "Red")
end
# => MockExpectationError raised
- This gem might work with instance methods as well, but its intent is (and it's only tested for) using it on class methods.
Bug reports and pull requests are welcome on GitHub at https://github.com/thatguysimon/minitest-stub_on_roids. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the Contributor Covenant code of conduct.
The gem is available as open source under the terms of the MIT License.