When tests are run on components written with makeStyle from https://material-ui.com/ library you will see plenty of those warnings in your console:
I've tracked down this issue through https://github.com/cssinjs/jss and found out the issue occurs if rule isn't valid by e.g. if some property miss the value.
Then cssRule becomes undefined and this error is thrown:
[JSS] Cannot set property 'parentStyleSheet' of undefined
Imo as original insertRule doesn't throw this error for invalid rules it should work the same in CSSOM.
If you need help with fixing it, please let me know. :)
When tests are run on components written with
makeStylefrom https://material-ui.com/ library you will see plenty of those warnings in your console:I've tracked down this issue through https://github.com/cssinjs/jss and found out the issue occurs if rule isn't valid by e.g. if some property miss the value.
Then
cssRulebecomesundefinedand this error is thrown:Imo as original
insertRuledoesn't throw this error for invalid rules it should work the same in CSSOM.If you need help with fixing it, please let me know. :)