Getting error (in development mode) when using a function (which has a custom toString method) inside css

[kireerik]

Current behavior:
I am getting the following error:

emotion/packages/serialize/src/index.js

Lines 182 to 186 in f3b268f

	'Functions that are interpolated in css calls will be stringified.\n' +
	'If you want to have a css call based on props, create a function that returns a css call like this\n' +
	'let dynamicStyle = (props) => css`color: ${props.color}`\n' +
	'It can be called directly with props or interpolated in a styled call like this\n' +
	"let SomeComponent = styled('div')`${dynamicStyle}`"

Expected behavior:
Getting no error at all.

Environment information:

• react version: none
• @emotion/react version: none

 
I recommend we modify the following line:

emotion/packages/serialize/src/index.js

Line 180 in f3b268f

} else if (process.env.NODE_ENV !== 'production') {

like this for example:

      } else if (process.env.NODE_ENV !== 'production' && interpolation.toString.toString() == 'function toString() { [native code] }') {

[kireerik]

Also it would be nice if objects are stringified as well in case they have a custom (non native code) toString method.