localStorage.removeItem creates key with arbitrary value from state

[AntonioGargaro]

Description

Using window.localStorage.removeItem within the amp-script worker using any value (even if it doesn’t exist) actually creates an item in local storage with that key and a value that is defined somewhere in AMP environment.

It can be reproduced by having the removeItem code within the amp-script JS that is guaranteed to be executed. The expected behaviour would be for this value to just be deleted.

cc @samouri

Reproduction Steps

Added an AMP playground link here. On line 27 I added window.localStorage.removeItem and you can see that the helloworld key to be removed is actually created in localstorage.

Relevant Logs

No response

Browser(s) Affected

Chrome, Firefox, Safari

OS(s) Affected

No response

Device(s) Affected

No response

AMP Version Affected

No response

[AntonioGargaro]

@samouri This appears to be back again, can someone confirm?