Default flags are ignored during the first render

[taschetto]

Describe the bug
Flags are evaluated as false during the first render even if default flags are provided.

To Reproduce
Steps to reproduce the behavior:

1. Clone https://github.com/taschetto/flopflip-bug
2. yarn && yarn start
3. Open the console DevTools in your preferred browser
4. Notice that the first render outputs false for all feature flags, even though the defaults are different
5. Then, eventually, the flags assume the default value

Expected behavior
Any tentative to evaluate flags should read from the default flags even during the first render.

Screenshots

[tdeekens]

Hi, thanks for reporting the issue. Personally I've not perceived this as an issue so far but that depends on the case. Have you had a look around the library to gauge how to possibly fix it?

[taschetto]

I consider this an inconvenience, especially for non-boolean feature flags. For example, that particular flag dashboardColor has many variants that return a hex color. If I try to use the variant as-is in CSS properties, I'll have an invalid value during a few renders. Of course, this can be circumvented in the consumer with some explicit defaults/fallbacks, but it begins to be a hassle once your consumers grow in complexity or number. This can be a problem while writing unit tests as well since the first render will not include the valid flags, and we need to introduce some mechanism to wait for it to be in the correct state.

Yes, I read the documentation, but so far, I couldn't find a solution.

[noseworthy]

Perhaps return undefined until the flag first evaluates? Would that be distinct enough from possible flag variations to be detectible? Introducing some sort of "flag" of "I've received the first flag variation from the adapter" is likely a huge API change that's not worth it, but I think this is problematic especially for flags that exist early on in the apps lifecycle.

We're doing some cursed thing where we have a flag that is always set to true in LaunchDarklyand only evaluate other flags once that one stabilizes attrue` 😱 .

[tdeekens]

We're doing some cursed thing where we have a flag that is always set to true in LaunchDarklyand only evaluate other flags once that one stabilizes attrue` 😱 .

Doesn't LaunchDarkly support this natively through pre-requisites? Where the "On" Requirement: To satisfy a prerequisite, the prerequisite flag must be explicitly turned On. If a prerequisite flag is Off, the prerequisite is considered unmet regardless of what variation the target is receiving.

https://launchdarkly.com/docs/home/flags/prereqs