This image documents the fundamental problem.
http://www.gsartchive.com/Temp/Fix_Masking.png

It's not just the 'Asset Export' functionality though it also applies to alignment. At times Ai will consider the unseen content in the mask and align to that even though focus is on the mask shape.

Please merge with https://illustrator.uservoice.com/forums/601447-illustrator-bugs/suggestions/34968397-asset-export-should-respect-clipping-mask

Another visual example here : https://twitter.com/vonster/status/1047254883047333888?s=21

fix this before I fix Adobe illustrator and install sketch

bump - Annoying as fxck

Yes, exactly this problem yesterday! I'm trying to export my 6 designs from Illustrator to Photoshop, then I have the white borders! I stayed so late at work, this makes me look bad! I was able to crop the white areas out manually in Photoshop, which just adds too many steps. I hate this! We pay $$$ a year to have all the Adobe Products. Now I'm going back, creating 6 separate art boards, etc...This feature needs to be fixed ASAP! I'm taking waaaaay to long to complete my project. Help! Adobe, help us now!

Seriously- have an option for this- we need it in the assets export

This "feature request" is extremely polite. The truth is this isn't a feature that needs to be requested, its definitely a bug! The current functionality benefits nobody and is clearly a mistake that Adobe have completely embarrassed themselves by leaving unfixed for years. Like somebody said below, it's as if the devs have never used the program. How this got through testing and into a final released product is beyond me.

Adobe's own staff admit this is a bug, but have chosen to ignore their community:
See: https://forums.adobe.com/thread/2174453
and: https://forums.adobe.com/thread/2243612

Unfortunately Adobe don't seem to have a Bug reporting option, so their own support staff recommend people request a bug fix as a "feature request".

AshutoshChaturvedi Employee 24-Nov-2017 07:34:
"The root cause can be linked to our rasterize function. You will find a similar issue with Object menu >Rasterize. We do see the value in this request .

Please vote on this here: Option to export to clipping mask boundaries – Adobe Illustrator Feedback
we will review the request."

Adobe, please end this embarrassment.

Wake up Adobe! :)

+1 it's very important for asset export workflow...

Come on Adobe, just fix this, please!

+1 It's like the developers of AI don't even use it.

I 100% agree with the concerns of fellow illustrator users. I just started study which requires some illustrator use, and I still can't believe I had to revert to using MS Paint to crop my designs. Shame! Shame!

I 100% agree with the concerns of fellow illustrator users. I just started study which requires some illustrator use, and I still can't believe I had to revert to using MS Paint to crop my designs. Fix this shite!

If the folks at Adobe don't see the practicality of this feature request and act on it in a timely manner, shame on them!

Please fix this!!!!

This is my main complaint about Illustrator's functionality these days. It's a real pain to have to open photoshop every time I export an image with a clipping mask.

There should definitely be something under advanced export settings to recognize clipping masks as boundaries.

See attached image for clarification. Currently, rasterizing a clipping group results in an image that is the size of the entire group bounds, rasterized as extra white space.

It would be much better IMO if the resulting image was automatically cropped to the clipping object's bounds. It would also be nice if for non-rectangular clipping masks, all areas outside of the clipping object's shape were rasterized as fully transparent.

PNG export should recognize clipping masks, or we should have an option if we want that or not.

YUP. 100% true. WHAT THE ****? Billion dollar company and it's simply 1s and 0s....