cfurrow/rspec-mocks-fail-example

rspec-mocks failure example

Related to rspec/rspec-mocks#1499

Upgrading from rspec-mocks v3.11.1 to v3.11.2 or v3.12.0 seems to cause some issues with the receive matcher (or related).

You'll see in spec/lib/analytics_service_spec.rb there are two examples. They do very similar things, but one will always fail when not using the .receive() block form. When we call .receive(...).with(...) it will always fail. But replacing that with .receive(...) do |arg| will make it pass.

How to test

bin/rspec

Then you'll see these two examples; one passes, one fails:

AnalyticsService
  .track
    does not fail when I use .receive().with() (FAILED - 1)
    does not fail when I use .receive() block-form

Failures:

  1) AnalyticsService.track does not fail when I use .receive().with()
     Failure/Error: tracker.track(payload)

       #<Tracker:0x0000000107ddf510> received :track with unexpected arguments
         expected: ({:anonymous_id=>nil, :event=>"foobar", :properties=>{:deployment_type=>"standard", :fake_property=>"f...9}, :timestamp=>#<DateTime: 2020-01-01T00:00:00+00:00 ((2458850j,0s,0n),+0s,2299161j)>, :user_id=>1}) (keyword arguments)
              got: ({:anonymous_id=>nil, :event=>"foobar", :properties=>{:deployment_type=>"standard", :fake_property=>"f...9}, :timestamp=>#<DateTime: 2020-01-01T00:00:00+00:00 ((2458850j,0s,0n),+0s,2299161j)>, :user_id=>1}) (options hash)
       Diff:

     # ./lib/analytics_service.rb:26:in `track'
     # ./spec/lib/analytics_service_spec.rb:31:in `block (3 levels) in <top (required)>'

Finished in 0.03275 seconds (files took 0.15496 seconds to load)
2 examples, 1 failure

Failed examples:

rspec ./spec/lib/analytics_service_spec.rb:23 # AnalyticsService.track does not fail when I use .receive().with()