Error in FF DOMException: "The quota has been exceeded."?

Question

JavaScript

There is an application in angular 8. In all browsers, everything works fine (even in edge), but in FF, after some time, an exception pops up.
At first I thought that localStorage somehow overflowed, but in the end it didn’t.
Who faced, who will tell?

Answer 1

I observed this in the Dev version of Firefox 85.0b4 after a long use, more than a month. It is possible that it will also appear in the stable version, but the error seems to have accumulated over a long time, so I don’t know how to repeat it.
At the same time, in the unused stable version of Firefox and in the used stable version of Chrome, everything is fine.
It manifests itself in the fact that a single write of a small harmless value in localStorage leads to the subsequent impossibility of writing with a "quota" error. Checking the real volume of the script writing to Storage an increasingly large amount of data shows that, in fact, nothing can be written. After localStorage.clear(), writing is again possible, but to a smaller extent than specified in dom.storage.default_quota. Over time, there seems to be a tendency for this limit to decrease.
This does not interfere with reading existing records, but it is possible to write before the error either very few KB (5-100), or the error does not allow writing. indexedDB is completely empty on the domain, there are only a few cookies.
At the same time, everything works fine on another domain of the same browser, as in Chrome.
Although it is very likely that this is a browser bug, I had to add automatic cleaning of the localStorage by localStorage.clear(), with the restoration of my records, since it is possible that it will also be observed in stable versions of the browser.
And it is impossible to describe the bug report, because. playback procedure unknown.