pxToRem() doesn't support negative values

[bcalvery]

Bug Report

Steps

pass a negative value to the pxToRem function

Expected Result

I expect a negative Rem value to be returned

Actual Result

An error is thrown "Invalid value of: …"

Code:

export const pxToRem = (value: number = 0): string => { if (!_htmlFontSizeInPx) { _htmlFontSizeInPx = getComputedFontSize() } if (process.env.NODE_ENV !== 'production') { **if (value < 0) { throw new Error(Invalid value of: '${value}'.) }** } const convertedValueInRems = value / _htmlFontSizeInPx return ${_.round(convertedValueInRems, 4)}rem }

[hughreeling]

Closely related to changes in #371. I hope fix will be added to that.