Rspec-core: `when_first_matching_example_defined` runs when all matching examples are filtered out

[ojab]

Your environment

• Ruby version: 2.5.7
• rspec-core version: 3.8.2

Steps to reproduce

1.

config.when_first_matching_example_defined(type: :feature) do
  require 'support/db'
end

1. Have an example with type: :feature
2. bundle exec rspec -t ~type:feature

Expected behavior

require 'support/db' is not run

Actual behavior

require 'support/db' is run

[JonRowe]

:wave: It's when the example is defined, not when its run. You've loaded the example and filtered it out, which is defined, but skipped. This is thus working as designed and documented.

[JonRowe]

Without knowing the contents of your support/db I can't help with much advice, but you can then add something else to be run when the first example runs to setup the db etc.

[pirj]

Hey Slava 👋

I can suggest using a regular before hook with some trigger-once check:

before(:example, type: :feature) do
  only_once { require 'support/db' }
end

[JonRowe]

Fun fact, require 'support/db' will only run once provided its the same path.

[pirj]

Agree, it's a bad example. A slightly better one:

before(:example, type: :feature) do
  only_once { expensive_setup }
end

[ojab]

I knew had a clue that answer would be that, thanks anyway :)