Add Rails/ActiveSupport hooks support for Vernier profiles

[palkan]

Context

Vernier allows adding event markers from Active Support Notifications.

This functionality must be explicitly enabled via the hooks: [:rails] option for the Collector.

This will add more insights to the resulting report. For example, we can see which initializers are being executed during the application boot and how much time did they take:

TODO

Add new configuration parameter to the Vernier wrapper (test_prof/vernier.rb) to add hooks: [:rails] when initializing the collector.

This should be possible via both Ruby and env variables (TEST_VERNIER_HOOKS=rails).

See also

• https://github.com/jhawthorn/vernier/blob/f8976625d7b5cfeeddb8471750f1ca93cf10d5aa/lib/vernier/collector.rb#L31
• Add custom markers  jhawthorn/vernier#64