@mui/base/modern/utils/mergeSlotProps.js

import _extends from "@babel/runtime/helpers/esm/extends";
import clsx from 'clsx';
import { extractEventHandlers } from './extractEventHandlers';
import { omitEventHandlers } from './omitEventHandlers';
/**
 * Merges the slot component internal props (usually coming from a hook)
 * with the externally provided ones.
 *
 * The merge order is (the latter overrides the former):
 * 1. The internal props (specified as a getter function to work with get*Props hook result)
 * 2. Additional props (specified internally on a Base UI component)
 * 3. External props specified on the owner component. These should only be used on a root slot.
 * 4. External props specified in the `slotProps.*` prop.
 * 5. The `className` prop - combined from all the above.
 * @param parameters
 * @returns
 */
export function mergeSlotProps(parameters) {
  const {
    getSlotProps,
    additionalProps,
    externalSlotProps,
    externalForwardedProps,
    className
  } = parameters;
  if (!getSlotProps) {
    // The simpler case - getSlotProps is not defined, so no internal event handlers are defined,
    // so we can simply merge all the props without having to worry about extracting event handlers.
    const joinedClasses = clsx(additionalProps?.className, className, externalForwardedProps?.className, externalSlotProps?.className);
    const mergedStyle = _extends({}, additionalProps?.style, externalForwardedProps?.style, externalSlotProps?.style);
    const props = _extends({}, additionalProps, externalForwardedProps, externalSlotProps);
    if (joinedClasses.length > 0) {
      props.className = joinedClasses;
    }
    if (Object.keys(mergedStyle).length > 0) {
      props.style = mergedStyle;
    }
    return {
      props,
      internalRef: undefined
    };
  }

  // In this case, getSlotProps is responsible for calling the external event handlers.
  // We don't need to include them in the merged props because of this.

  const eventHandlers = extractEventHandlers(_extends({}, externalForwardedProps, externalSlotProps));
  const componentsPropsWithoutEventHandlers = omitEventHandlers(externalSlotProps);
  const otherPropsWithoutEventHandlers = omitEventHandlers(externalForwardedProps);
  const internalSlotProps = getSlotProps(eventHandlers);

  // The order of classes is important here.
  // Emotion (that we use in libraries consuming Base UI) depends on this order
  // to properly override style. It requires the most important classes to be last
  // (see https://github.com/mui/material-ui/pull/33205) for the related discussion.
  const joinedClasses = clsx(internalSlotProps?.className, additionalProps?.className, className, externalForwardedProps?.className, externalSlotProps?.className);
  const mergedStyle = _extends({}, internalSlotProps?.style, additionalProps?.style, externalForwardedProps?.style, externalSlotProps?.style);
  const props = _extends({}, internalSlotProps, additionalProps, otherPropsWithoutEventHandlers, componentsPropsWithoutEventHandlers);
  if (joinedClasses.length > 0) {
    props.className = joinedClasses;
  }
  if (Object.keys(mergedStyle).length > 0) {
    props.style = mergedStyle;
  }
  return {
    props,
    internalRef: internalSlotProps.ref
  };
}