@trpc/server/src/vendor/is-plain-object.ts

The tRPC server library

/*!
 * is-plain-object <https://github.com/jonschlinkert/is-plain-object>
 *
 * Copyright (c) 2014-2017, Jon Schlinkert.
 * Released under the MIT License.
 */

function isObject(o: unknown): o is Record<string, unknown> {
  return Object.prototype.toString.call(o) === '[object Object]';
}
  
export function isPlainObject(o: unknown): o is Record<string, unknown> {
  var ctor,prot;

  if (isObject(o) === false) return false;

  // If has modified constructor
  ctor = o.constructor;
  if (ctor === undefined) return true;

  // If has modified prototype
  prot = ctor.prototype;
  if (isObject(prot) === false) return false;

  // If constructor does not have an Object-specific method
  if (prot.hasOwnProperty('isPrototypeOf') === false) {
    return false;
  }

  // Most likely a plain Object
  return true;
};