moltres-utils/dist/data/defn.js

Utils for Moltres apps

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.default = void 0;

var _isArray = _interopRequireDefault(require("./isArray"));

var _isFunction = _interopRequireDefault(require("./isFunction"));

var _isObject = _interopRequireDefault(require("./isObject"));

var _nArySpread = _interopRequireDefault(require("./nArySpread"));

function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }

/**
 * Defines a function that will invoke the named function if it exists on the
 * last arg. If the method does not, all args are passed through to the default
 * function.
 *
 * @func
 * @since v0.1.0
 * @category data
 * @sig defn(
 *   name: string,
 *   defaultFn: (*) => any
 * ): (...args: any[], last: any) => last[name] ? last[name](...args) : defaultFn(...args)
 * @param {string} name The name of the method to call if it exists
 * @param {Function} defaultFn The default function to execute if the named one does not exist on the last arg
 * @returns {Function} The wrapped function
 * @example
 *
 * const get = defn('get', (prop, value) => value[prop])
 * get('a', { a: 'foo' }) //=> 'foo'
 *
 * const obj = {
 *   props: {
 *     a: 'bar'
 *   }
 *   get: (prop) => obj.props[prop]
 * }
 * get('a', obj) //=> 'bar'
 */
const defn = (name, defaultFn) => {
  const arity = defaultFn.length;

  const override = function override(...args) {
    if (args.length === 0) {
      return defaultFn.apply(this);
    }

    const obj = args[args.length - 1];

    if (!(0, _isArray.default)(obj) && (0, _isObject.default)(obj) && (0, _isFunction.default)(obj[name]) && obj !== this) {
      return obj[name](...args);
    }

    return defaultFn.apply(this, args);
  };

  return (0, _nArySpread.default)(arity, override);
};

var _default = defn;
exports.default = _default;
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