Combination of "requiredMetaFields" and "metaFields" as function call

[jvelten]

Initial checklist

• I understand this is a bug report and questions should be posted in the Community Forum
• I searched issues and couldn’t find anything (or linked relevant results below)

Link to runnable example

https://codesandbox.io/s/uppy-dashboard-forked-i4iuvf

Steps to reproduce

Combination of "restrictions.requiredMetaFields" in Uppy.Core and "metaFields" in Uppy.Dashboard as function call results in an error inside uppy-library on opening the FileCard to edit metafields (auto-open after upload in the attached sandbox).

Expected behavior

Making sure that the metafields to call is an array before calling filter().

Actual behavior

Theres a filter() call on metafields, so excepted is an array but it is possible to define metafields as a function call.
Error message: "Uncaught (in promise) TypeError: metaFields.filter is not a function"

[Murderlon]

Good catch, thanks