@mui/utils/esm/resolveProps/resolveProps.js

Utility functions for React components.

import clsx from 'clsx';

/**
 * Add keys, values of `defaultProps` that does not exist in `props`
 * @param defaultProps
 * @param props
 * @param mergeClassNameAndStyle If `true`, merges `className` and `style` props instead of overriding them.
 *   When `false` (default), props override defaultProps. When `true`, `className` values are concatenated
 *   and `style` objects are merged with props taking precedence.
 * @returns resolved props
 */
export default function resolveProps(defaultProps, props, mergeClassNameAndStyle = false) {
  const output = {
    ...props
  };
  for (const key in defaultProps) {
    if (Object.prototype.hasOwnProperty.call(defaultProps, key)) {
      const propName = key;
      if (propName === 'components' || propName === 'slots') {
        output[propName] = {
          ...defaultProps[propName],
          ...output[propName]
        };
      } else if (propName === 'componentsProps' || propName === 'slotProps') {
        const defaultSlotProps = defaultProps[propName];
        const slotProps = props[propName];
        if (!slotProps) {
          output[propName] = defaultSlotProps || {};
        } else if (!defaultSlotProps) {
          output[propName] = slotProps;
        } else {
          output[propName] = {
            ...slotProps
          };
          for (const slotKey in defaultSlotProps) {
            if (Object.prototype.hasOwnProperty.call(defaultSlotProps, slotKey)) {
              const slotPropName = slotKey;
              output[propName][slotPropName] = resolveProps(defaultSlotProps[slotPropName], slotProps[slotPropName], mergeClassNameAndStyle);
            }
          }
        }
      } else if (propName === 'className' && mergeClassNameAndStyle && props.className) {
        output.className = clsx(defaultProps?.className, props?.className);
      } else if (propName === 'style' && mergeClassNameAndStyle && props.style) {
        output.style = {
          ...defaultProps?.style,
          ...props?.style
        };
      } else if (output[propName] === undefined) {
        output[propName] = defaultProps[propName];
      }
    }
  }
  return output;
}