import _extends from "@babel/runtime/helpers/esm/extends"; import { getDisplayName } from '@material-ui/utils'; export default function mergeClasses(options = {}) { const { baseClasses, newClasses, Component } = options; if (!newClasses) { return baseClasses; } const nextClasses = _extends({}, baseClasses); if (process.env.NODE_ENV !== 'production') { if (typeof newClasses === 'string') { console.error([`Material-UI: The value \`${newClasses}\` ` + `provided to the classes prop of ${getDisplayName(Component)} is incorrect.`, 'You might want to use the className prop instead.'].join('\n')); return baseClasses; } } Object.keys(newClasses).forEach(key => { if (process.env.NODE_ENV !== 'production') { if (!baseClasses[key] && newClasses[key]) { console.error([`Material-UI: The key \`${key}\` ` + `provided to the classes prop is not implemented in ${getDisplayName(Component)}.`, `You can only override one of the following: ${Object.keys(baseClasses).join(',')}.`].join('\n')); } if (newClasses[key] && typeof newClasses[key] !== 'string') { console.error([`Material-UI: The key \`${key}\` ` + `provided to the classes prop is not valid for ${getDisplayName(Component)}.`, `You need to provide a non empty string instead of: ${newClasses[key]}.`].join('\n')); } } if (newClasses[key]) { nextClasses[key] = `${baseClasses[key]} ${newClasses[key]}`; } }); return nextClasses; }