import { Breakpoint, Theme, ThemeProvider, useTheme, createTheme, } from '@mui/material/styles'; import useMediaQuery from '@mui/material/useMediaQuery'; type BreakpointOrNull = Breakpoint | null; /** * Be careful using this hook. It only works because the number of * breakpoints in theme is static. It will break once you change the number of * breakpoints. See https://legacy.reactjs.org/docs/hooks-rules.html#only-call-hooks-at-the-top-level */ function useWidth() { const theme: Theme = useTheme(); const keys: readonly Breakpoint[] = [...theme.breakpoints.keys].reverse(); return ( keys.reduce((output: BreakpointOrNull, key: Breakpoint) => { // TODO: uncomment once we enable eslint-plugin-react-compiler // eslint-disable-next-line react-compiler/react-compiler -- useMediaQuery is called inside callback // eslint-disable-next-line react-hooks/rules-of-hooks const matches = useMediaQuery(theme.breakpoints.up(key)); return !output && matches ? key : output; }, null) || 'xs' ); } function MyComponent() { const width = useWidth(); return {`width: ${width}`}; } const theme = createTheme(); export default function UseWidth() { return ( ); }