CODEWITHSUNDEEP
rubyunit-testingminitest
codebee
codebee

Reputation: 844

How to mock a method call in Ruby

I'm writing a test method for Class A, method called m().

m() calls f() on Class B through an instance of B called 'b', but I mock that method call using-

def test_m 
@a = A.new
b_mock = MiniTest::Mock.new
b_mock.expect(:f, 'expected_output')
def b_mock.f()
return 'expected output'
end
@a.b = b_mock
end

Now A has another method m1(), how can a mock a call to it and get a constant output, using the above or a better approach with Minitest?

Error-

NoMethodError: unmocked method :get_group_by_name, expected one of [:]

Upvotes: 1

Views: 4595

Answers (1)

Dmitry Sokurenko
Dmitry Sokurenko

Reputation: 6132

You can use MiniTest Object#stub method, it redefines the method result for the duration of the block.

require 'minitest/mock'

class A
  def m1
    m2
    'the original result'
  end

  def m2
    'm2 result'
  end
end

@a = A.new
@a.stub :m1, "the stubbed result" do

  puts @a.m1  # will print 'the stubbed result'
  puts @a.m2

end

Read more: http://www.rubydoc.info/gems/minitest/4.2.0/Object:stub

Upvotes: 3

Related Questions