Toggle customer balance to entire instance

[sauloperez]

What? Why?

Closes #6804

This refactors the feature toggles implementation to make it flexible enough to fit more complex toggling strategies such as enabling a feature for an entire OFN instance.

For reviewers, going commit by commit might be easier to understand.

What should we test?

spec/initializers/feature_toggles_spec.rb covers this (yes, it's the first time I test an initializer but it's proven enough) but I'd like you @filipefurtad0 to give it a try so you get acquainted with it and can give me feedback. I guess this can ease testing toggled features.

Release notes

Enabled toggling a feature to an entire instance.
Changelog Category: Technical changes

[sauloperez]

I feel like we're getting closer and closer to fully reinventing the wheel and having to switch to https://github.com/jnunemaker/flipper. Let's see if can get going a bit more.

[sauloperez]

@jibees thanks for the thorough review. This revealed a deeper issue that I addressed in 88e22a7. Now I'm fully confident we're covered for future refactorings of the feature flags.

[Matt-Yorkley]

Those flaky specs are different in each build, and they're flaky elsewhere, so I think we can merge 👌

[sauloperez]

I tested it locally and it's working as expected. BETA_TESTERS=all also toggles it on.

[filipefurtad0]

Ok, thank for testing this @sauloperez . I'll get familiar with this pull request after merge 👍

[filipefurtad0]

One question about this @sauloperez : BETA_TESTERS=all toggles a feature for all users; but I've found it not to be toggled for guest users. Is this intended? Is there a way to toggle a feature which is not based on email addresses?

[sauloperez]

but I've found it not to be toggled for guest users.

what do you mean by guest users here? To me, guest user => no user record in our DB for the user that's checking the browser.

Is there a way to toggle a feature which is not based on email addresses?

yes. We enabled :unit_price based on the environment is running on (staging and development), for instance.

[filipefurtad0]

I mean it as an un-logged user. For example, unit prices in #6905 - only appear in the shopfront after a user logs in. If the user logs out the feature is gone as well.

Maybe I'm missing how to activate this on the environment level.

[sauloperez]

Now I see. Toggles are based on the logged-in user; we choose what criteria should they meet in order for the feature to be enabled for them. Without a user (aka. contexts where you don't need to log in) that cannot happen.

The environment is just one of the myriad of criteria we can choose, but again it's all about which environment the logged user is checking.

[RachL]

Nice convo! I think this is interesting to remember for features we want to toggl for an entire hub (it would by default exclude guest shoppers), am I understanding correctly?

[sauloperez]

so far, yes. I think we all see that a toggle's criteria can escalate pretty quickly and become too hard to reason about, right? 😂 something to keep in mind.