Metamath-lamp (Lite Assistant for Metamath Proofs) is a GUI-based proof assistant for creating formal mathematical proofs in Metamath that does not require installation (just run it directly using your web browser).
But, this adds all 4 fields to the record (which can be seen in the debugger) with optional fields having the value 'undefined'. The original method didn't have this problem since it used the legacy function ReactDOMRe.domProps.
The only way that I could duplicate the original was to use the spread "..." functionality.
Note that I could have used instead of Some(resultRef.contents):
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But, this adds all 4 fields to the record (which can be seen in the debugger) with optional fields having the value 'undefined'. The original method didn't have this problem since it used the legacy function ReactDOMRe.domProps.
The only way that I could duplicate the original was to use the spread "..." functionality.