I think this is mostly consistent in terms of effect. With
any application of import attributes that affect the dependency, the dependent module could behave differently for any affected aspect it accesses.
The only inconsistency is that Bun is front loading some of these effects to the server/bundler runtime and effectively memoizing the equivalent behavior before it reaches a client. But it’s not doing that of its own volition, it’s doing it to address an explicit attribute in the source code.
The only way this would be a meaningful problem is if the explicit value has a chance of colliding with either existing code in the ecosystem (highly unlikely, no one is really using this syntax yet except perhaps in an equally experimental context), or some plausible pending standard (unless one was proposed in the last couple weeks, I’m pretty sure I can rule that out too).
I share other commenters’ lament that this is not a true macro solution (and I think it should actually just be renamed to something like comptime). But I don’t think this deserves the deviation-from-standards challenge it’s getting in this thread. And lest I come off as a Bun fanatic, I think I’m one of the people who more frequently questions potential Bun spec deviations when they come up on Twitter.