How to use Material UI custom theme in React with Typescript

Question

Using this tool https://react-theming.github.io/create-mui-theme/ I get a js file and a json file as mentioned on above theme generator page in respective paths as mentioned:

// src/ui/theme/index.js
/* src/ui/theme/theme.json */

Now they work fine when I leave the file extension to js. As soon as I try to use js as a tsx file the editor starts complaining. I have all the necessary setup done via CRA Typescript in tsconfig file also. Also necessary config from this page https://material-ui.com/guides/typescript/

When I try this it does not work, any ideas if I am missing something?

// My amended index.tsx file

import { createMuiTheme } from '@material-ui/core/styles';

const palette = {
  primary: { main: '#3f51b5' },
  secondary: { main: '#f50057' }
};
const themeName = 'San Marino Razzmatazz Sugar Gliders';

export default createMuiTheme({ palette, themeName });

Also the theme.json is untouched by me. I am still learning sorry, any ideas if this is an interface problem and how to use it?

Answer 1

Material UI custom theme V5

Material UI custom theme in React with Typescript v4->v5 migration guide. create separate file for declaration.

👉 theme.d.ts

import { Theme, ThemeOptions } from '@mui/material/styles';

declare module '@mui/material/styles' {
  interface CustomTheme extends Theme {
    status: {
      danger: string;
    };
  }
  // allow configuration using `createTheme`
  interface CustomThemeOptions extends ThemeOptions {
    status?: {
      danger?: string;
    };
  }
  export function createTheme(options?: CustomThemeOptions): CustomTheme;
}

it will override default createTheme function with custome theme configuration. now you can use custom config in theme as mention below 👇.

👉 theme.ts

import { createTheme } from '@mui/material/styles';
import { orange, red } from '@mui/material/colors';

const theme = createTheme({
  status: {
    danger: red[500],
  },
  palette: {
    primary: {
      main: orange[500],
    },
  },
});

export default theme;