styled-system props typing with TypeScript

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I’m using styled-system and one key of the library is to use the shorthand props to allow easy and fast theming.

I’ve simplified my component but here is the interesting part:

import React from 'react'
import styled from 'styled-components'
import { color, ColorProps } from 'styled-system'

const StyledDiv = styled('div')<ColorProps>`
  ${color}
`

const Text = ({ color }: ColorProps) => {
  return <StyledDiv color={color} />
}

I have an error on the color prop which says:

Type ‘string | (string | null)[] | undefined’ is not assignable to
type ‘string | (string & (string | null)[]) | undefined’.

I think that’s because styled-system use the same naming as the native HTML attribute color and it conflicts.

How do I solve this?

21 thoughts on “styled-system props typing with TypeScript”

  2. color seems to be declared in react’s declaration file under HTMLAttributes – it’s not exported.

    I had to work around this by creating a custom prop

    Example is using @emotion/styled but also works with styled-components

    // component.js
import styled from '@emotion/styled';
import { style, ResponsiveValue } from 'styled-system';
import CSS from 'csstype';

const textColor = style({
  prop: 'textColor',
  cssProperty: 'color',
  key: 'colors'
});


type Props = {
  textColor?: ResponsiveValue<CSS.ColorProperty>
}

const Box = styled.div<Props>`
  ${textColor};
`

export default Box;

    // some-implementation.js
import Box from '.';

const Page = () => (
  <Box textColor={['red', 'green']}>Content in a box</Box>
);
    Reply

  3. Building on Chris’ answer, and using the latest docs on on custom props.

    // core/constants/theme.ts
// Your globally configured theme file
export const theme = { colors: { primary: ['#0A43D2', '#04122B'] } }

// core/constants/styledSystem.ts
import {
  color as ssColor,
  ColorProps as SSColorProps,
  TextColorProps,
  compose,
  system,
} from 'styled-system'

// Styled-system patch for the color prop fixing "Types of property 'color' are incompatible"
// when appling props to component that extend ColorProps.
export interface ColorProps extends Omit<SSColorProps, 'color'> {
  textColor?: TextColorProps['color']
}

export const color = compose(
  ssColor,
  system({
    // Alias color as textColor
    textColor: {
      property: 'color',
      // This connects the property to your theme, so you can use the syntax shown below E.g "primary.0".
      scale: 'colors'
    }
  })
)

// components/MyStyledComponent.ts
import { color, ColorProps } from 'core/constants/styledSystem.ts'

interface MyStyledComponentProps extends ColorProps {}

export const MyStyledComponent = styled.div<MyStyledComponentProps>`
  ${color}
`

// components/MyComponent.ts
export const MyComponent = () => <MyStyledComponent textColor="primary.0">...

    EDIT: updating to styled-components ^5.0.0 fixes this

    https://github.com/styled-components/styled-components/blob/master/CHANGELOG.md#v500—2020-01-13

    Reply

  4. What I did was to use Typescript cast capabilities and keep styled-system logic intact. e.g.:

    const Heading: React.FC<ColorProps> = ({ color, children }) => {
  return <HeadingContainer color={(color as any)} {...props}>{children}</HeadingContainer>;
};
    Reply

  5. Just to add to xuanlopez‘ answer – not sure what issue the 5.0.0 release specifically resolves – but using $color as the renamed prop rather than textColor designates it as a transient prop in styled components so as a prop it won’t appear in the rendered DOM.

    Reply

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