fix(utils): warn only in development environment

[francoischalifour]

This is the new signature of the warning method:

warning(condition: boolean, message: string)

It logs a warning only if the condition is not met.

The condition is now part of the method so that the production UMD build is stripped correctly with less code.

[algobot]

Deploy preview for instantsearchjs ready!

Built with commit 5eb1e79

https://deploy-preview-3367--instantsearchjs.netlify.com

[Haroenv]

the boolean trap as first argument seems a bit odd, since I would be surprised if the bundler can actually detect this as unused code when DEV is false. It probably needs to have its own if around each of them

[francoischalifour]

The bundler does detect them. If we keep the wrapping if, it will transpile to something like:

// ...
{
  // whatever was here on top on the warning
}
// ...

With the condition inside the warning method, it's completely stripped.

FYI this is what React is doing for their invariant and warning functions.

[Haroenv]

Ah you're right, it's quite surprising that the bundler inlines those things. I didn't expect that, but that's good news!

Removed unnecessary checks.