Popper: throws an error in dev check

[layershifter]

TypeError
Cannot read property 'pendingProps' of undefined
    at hasAutofocusProp (https://1xhm3.csb.app/node_modules/
fluentui/react-northstar/dist/es/utils/positioner/Popper.js:31:165
    at Object.hasAutofocusFilter [as acceptNode] (https://1xhm3.csb.app/node_modules/
fluentui/react-northstar/dist/es/utils/positioner/Popper.js:34:10
    at eval (https://1xhm3.csb.app/node_modules/
fluentui/react-northstar/dist/es/utils/positioner/Popper.js:46:27

Environment Information

• Package version(s): @fluentui/react-northstar@0.51.3 & react@17
• Browser and OS versions: N/A

Please provide a reproduction of the bug in a codepen:

Open a CodeSandbox: https://codesandbox.io/s/dry-hooks-1xhm3
Click on an input.

Actual behavior:

Throws an error.

Expected behavior:

Opens a Datepicker.

[sushruth]

Currently this is affecting unit tests on apps using @fluentui/react-northstar and react 17. A milestone to look forward to will be much appreciated