add some means to assert that a stub was called

[geemus]

No description provided.

[geemus]

/cc @jkakar I know you have brought this up a couple times. Could you summarize what you have in mind and/or hook me up with a couple links to where you rolled your own? I'd like to do something here, but want to have a little better sense of the design goal before I get too far in to it. Thanks!

[jkakar]

Fundamentally, when I ask Excon to stub a request I expect it to blow
up if that request is never made. Stubbed requests that are never
invoked are silently ignored at present. I consider this a bug
because it's too easy for tests to spuriously pass when, in fact, none
of the assertions in the stubbed request block were ever run. To work
around that I pop stubbed requests out of Excon.stubs when they're
called and assert that all stubbed requests have been called when a
test ends.

I include this test helper in tests that mock Excon:

module ExconHelper
  def setup
    super
    Excon.stubs.clear
    Excon.defaults[:mock] = true
  end

  def teardown
    # FIXME This is a bit ugly, but Excon doesn't provide a builtin way to
    # ensure that a request was invoked, so we have to do it ourselves.
    # Without this, and the Excon.stubs.pop calls in the tests that use this
    # helper, tests will pass if request logic is completely removed from
    # application code. -jkakar
    assert(Excon.stubs.empty?, 'Expected HTTP requests were not made.')
    super
  end
end

I explicitly pop the stubbed request out of the Excon.stubs array in
the stubbed request block so that the check for Excon.stubs.empty?
in ExconHelper.teardown works correctly:

class LinkTest < MiniTest::Unit::TestCase
  include ExconHelper

  # Link.run invokes a request against the service identified by the URL.  The
  # path is left unchanged when parameters aren't required and the username
  # and password from the URL are passed using HTTP basic auth.
  def test_run_without_parameters_and_with_empty_response
    Excon.stub(method: :get) do |request|
      assert_equal('Basic dXNlcm5hbWU6c2VjcmV0',
                   request[:headers]['Authorization'])
      assert_equal('example.com', request[:host])
      assert_equal(443, request[:port])
      assert_equal('/resource', request[:path])
      Excon.stubs.pop
      {status: 200, body: ''}
    end

    schema = Heroics::Schema.new(SAMPLE_SCHEMA)
    link = Heroics::Link.new('https://username:secret@example.com',
                             schema.resource('resource').link('list'))
    assert_equal(nil, link.run)
  end
end

It's a bit ugly but it ensures that the tests are reliable.

[geemus]

@jkakar awesome, thanks for the context. Moving past the current, unfortunate state, thoughts on what invocation might look like in an idealized future?

[jkakar]

I like the API Excon provides for stubbing calls. It's simple and
intuitive. I think adding an Excon.verify_stubs call that can be
invoked in teardown to ensure that all stubbed requests were called
would be nice. If you want to make it a bit easier to consume you
could go the route of RR, for example, and provide builtin
integrations for popular test frameworks.

[geemus]

Good call. I'll probably start with something like #verify_stubs (when I get a chance) and work from there. Do you think boolean is good-enough? ie I've seen some tests where it would be something like called-only-once or called-twice or something. Just trying to figure out internally how to represent this. Maybe a hash of stub to count of calls (and verify would be true as long as all calls are > 1. Not sure I'd reveal the called-x-times stuff right away, but seems like it might be useful eventually and wouldn't be much different/harder than boolean I think/hope.

[stale]

This issue has been automatically marked stale due to inactivity. It will be closed if no further activity occurs. Thank you for your contributions.