Add preview flavor

[julien4215]

Reopening of #3396

[julien4215]

@julien4215 sorry I had to revert because this broke iOS. Can you reopen it please?

I'll have to make it work on iOS before merging, but can't do it now. Leave it as a draft for now, so we know it is not ready.

I didn't realize it would break iOS. I assume it is because there is a default flavor set in the pubspec.yaml that must be used by each platform. This is annoying because we either need to also add flavors to iOS or set no default flavor but then the usual flutter run command will have to become flutter run --flavor prod on android.

Related Flutter issue flutter/flutter#176820

[julien4215]

@veloce I think renaming the Xcode scheme to prod should solve the build issue on iOS. If that is preferable, we can rename the prod flavor to Runner instead.

Or we can remove the default-flavor from the pubspec.yaml but each flutter command that builds the app on android will need to specify a flavor, e.g. flutter run --flavor prod.

What do you think would be the best approach?

[veloce]

@veloce I think renaming the Xcode scheme to prod should solve the build issue on iOS. If that is preferable, we can rename the prod flavor to Runner instead.

Or we can remove the default-flavor from the pubspec.yaml but each flutter command that builds the app on android will need to specify a flavor, e.g. flutter run --flavor prod.

What do you think would be the best approach?

Not sure yet, I have to investigate. Ideally android and iOS should behave the same way so the work you did for android needs to be done for iOS too.

[veloce]

I rebased the branch fyi @julien4215 ; will add support for iOS from here.