@styled-system/theme-get

The themeGet function is an existential getter function
that can be used in any style declaration to get a value
from your theme, with support for fallback values.
This helps prevent errors from throwing when a theme value is missing,
which can be helpful when unit testing styled-components.

``sh
npm i @styled-system/theme-get
`

`js
themeGet(objectPath, fallbackValue)(props)
`

themeGet returns a function that accepts props as an argument
(themeGet(objectPath)(props)), which when used in a tagged template
literal should look like this:

`js
import styled from 'styled-components'
import { themeGet } from '@styled-system/theme-get'

const Box = styled.div
border-radius: ${themeGet('radii.small', '4px')};

`

When used with object literal syntax, themeGet needs to be in a
function call and have props passed to it:

`js
import styled from 'styled-components'
import { themeGet } from '@styled-system/theme-get'

const Box = styled('div')(props => ({
borderRadius: themeGet('radii.small', '4px')(props),
}))
``