MediaEdit: handle '*' wildcard in validateMimeType

[dinhtungdu]

What?

Closes #77149

Handle '*' wildcard in validateMimeType (@wordpress/media-utils) — skip MIME validation when allowedTypes contains '*'.

Why?

MediaUploadModal passes raw ['*'] to uploadMedia(). validateMimeType checks file.type.startsWith('*/') — always false — so every upload fails with "Sorry, this file type is not supported here."

How?

Early-return in validateMimeType when allowedTypes.includes('*').

Testing Instructions

1. Enable Data Views: new media modal (Gutenberg → Experiments)
2. Install test plugin: https://github.com/dinhtungdu/verify-wildcard-upload
3. Add Wildcard Upload Test block, open Inspector panel
4. Upload any file type — should succeed without MIME error

Testing Instructions for Keyboard

Logic-only change, no UI changes.

Screenshots or screencast

Before	After

Use of AI Tools

Authored with Claude Code (Anthropic).

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[dinhtungdu]

@ntsekouras @andrewserong apart from what's fixed in the PR, there is an inconsistency of our handling for button and modal. For button onFilesDrop, we normalize the value of allowedTypes before passing to handleUpload, so using an empty array for allowedTypes works there. But it doesn't work for modal because we pass the allowedTypes as is down to handleUpload.

I think we should unify the behavior across all upload paths. And we should be explicit about accepting all types, meaning having only one way (using wildcard) and document it. WDYT?

[andrewserong]

I think we should unify the behavior across all upload paths. And we should be explicit about accepting all types, meaning having only one way (using wildcard) and document it. WDYT?

I think consistency is a good idea in general, but in this case passing no allowedTypes at all implicitly means accepting all types, which is what the File block does, if I recall correctly? I lean a little toward using emptiness to indicate permissive accepting of types, rather than requiring folks to use *. I.e. if folks do want to be explicit about it, we should support it, but I think it makes things a little tidier if we don't require it.

That's not a strongly held opinion, though!

Another thing to keep in mind is that depending on the circumstances it can be advantageous to use the real supported mime types list instead of a wildcard, as was done in some cases last year in #73562

As for this fix, though, this one looks good to get in to me, thanks for handling it!

Edit: forgot to mention, keep in mind that if an absence of a value means it's implicitly treated as a wildcard, then folks will already be depending on this behaviour, so it might be hard to change in terms of backwards compatibility.

[dinhtungdu]

@andrewserong I see and agree that we need to support both case. For consumers, should we still promote a prefer way enable all allowed types, right? For me using wild card is quite straight forward and explicit. It's also an existing pattern. I updated the docs in 8f44396. But should we commit it now?

[andrewserong]

For me using wild card is quite straight forward and explicit. It's also an existing pattern. I updated the docs in 8f44396. But should we commit it now?

I'd lean a little toward a comment like Use ['*'] or leave undefined to allow all file types. so that the components don't take a stance on the matter. But adding the extra comments like you've done is a good idea as it does demonstrate to a consumer how they can do it. (i.e. IMO it's more important that we communicate that folks can do something than which way the should do something)

Whenever you're happy with it, I'd say you're good to merge!

[dinhtungdu]

The case with MediaEdit is, it defaults to ['image'], so we can't pass undefined, as the default value will be used. So I'll go ahead and merge this PR; we can always iterate later if needed.

[andrewserong]

The case with MediaEdit is, it defaults to ['image'], so we can't pass undefined, as the default value will be used. So I'll go ahead and merge this PR; we can always iterate later if needed.

Ah, I see! I think we had a bug with that in the media upload modal where we'd made it default to ['image'], too, but we forgot that the File block achieved the wildcard approach by simply not providing a value.

Yes, for MediaEdit let's leave it as is, then.

Thanks for the back and forth here! (And again for the fix 🎉 )