Two thoughts:

1. This could really stack up in unhelpful ways given the popularity of barrels and how large they can often become. I would maybe just add the related info once, as something like 'export *' does not re-export a default.
2. It only makes sense to issue this message if one or more of the ExportStar declaration targets actually has a default export.

I would maybe just add the related info once, as something like 'export *' does not re-export a default

@andrewbranch Thanks for your feedback 👍. Which node do I need to use to add related info?

I guess I’d attach it to the first one whose target has a default export.

@andrewbranch That makes it hard during incremental editing/diagnostics since then order of the checking would guide the diagnostic position ?

I could be wrong, but I don’t think that will be the case. exportStar.declarations should be filled by the binder in source order, and then you’d try to resolve the module (resolveExternalModuleName) of each one in order... the order of checking might determine whether those resolutions have already happened before, but I don’t see how that would affect the results you see when checking declarations in source order.