Function isPlainObject

packages/query-core/src/utils.ts:414–448

(o: any)

// Copied from: https://github.com/jonschlinkert/is-plain-object
export function isPlainObject(o: any): o is Record<PropertyKey, unknown> {
  if (!hasObjectPrototype(o)) {
    return false
  }

  // If has no constructor
  const objectPrototype = Object.getPrototypeOf(o)
  const ctor = objectPrototype?.constructor
  if (ctor === undefined) {
    return true
  }

  if (typeof ctor !== 'function') {
    return false
  }

  // If has modified prototype
  const prot = ctor.prototype
  if (!hasObjectPrototype(prot)) {
    return false
  }

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

  // Handles Objects created by Object.create(<arbitrary prototype>)
  if (objectPrototype !== Object.prototype) {
    return false
  }

  // Most likely a plain Object
  return true
}

function hasObjectPrototype(o: any): boolean {
  return Object.prototype.toString.call(o) === '[object Object]'