FIX Ensure environment is checked before enabling deprecations

[GuySartorelli]

Issue

• Ensure deprecation warnings are only enabled in dev mode. #11054

[michalkleiner]

Good catch, that didn't occur to me when we approved the previous change.

MOG

[GuySartorelli]

I think I've still got it wrong - I'm gonna add checking the static currentlyEnabled to the test. Marking as draft in the meantime.

PR turned to draft for further changes

[GuySartorelli]

There we go, this should be correct and tests all scenarios.

• Environment mode is only ever checked if the deprecations are enabled
• If SS_DEPRECATION_ENABLED is set, we ignore the static $currentlyEnabled

[GuySartorelli]

And one last change to make the relationship between the static and the env variable clearer. This is ready for review now.

[michalkleiner]

It's quite hard to read compared to what it was before, but I think we need both the nested and the elseif stanzas.

1. if env var set and explicitly disabled -> disabled
2. if env var set and not disabled -> disable for non-dev, otherwise allow
3. if env var NOT set, and not enabled via static prop -> disabled
4. if env var NOT set, and explicitly enabled via static prop -> still disable for non-dev, otherwise allow

[emteknetnz]

This should target 4.13? PR that was originally made targeted 4.13 - #11053

[GuySartorelli]

Yup, I must have forgotten to swap the target branch. Fixed and force-pushed to kick off tests again.