Allowed file extensions Widget Input/Display Length Problem

Converted to an MR and made a change for #59.

This looks fine, but do we really need a test for this? Surely the maxlength property is tested elsewhere?

I think we should also revisit removing the maxlength as per #38 and fixing the tests that failed because of it (as reported in #43)

The maxlength property is working properly.
But one behavior in which if I specify the extension list comma separated such as txt,doc,docx,pdf,ppt it auto-replacing the commas with spaces which is not a good developer experience.

In addition to this if ae are replacing the commas with spaces then we need to change the description as well from
Separate extensions <strong>with a comma or space</strong>. Each extension can contain alphanumeric characters, '.', and '_', and should start and end with an alphanumeric character.
to
Separate extensions <strong>with a space</strong>. Each extension can contain alphanumeric characters, '.', and '_', and should start and end with an alphanumeric character.

Re #65 that happens currently (as in without the patch) and is intended functionality.

@acbramley think it's worth getting this fixed and a follow up to look into deprecating #maxlength?

@smustgrave - no it's not about deprecating it, just removing the property entirely from this element, it's unnecessary afaict

Updated the issue summary to use the standard template.

Added remaining task to remove #maxlength

Also solution should portion should be flushed out