om/node_modules/setprototypeof/test/index.js

'use strict'
/* eslint-env mocha */
/* eslint no-proto: 0 */
var assert = require('assert')
var setPrototypeOf = require('..')

describe('setProtoOf(obj, proto)', function () {
  it('should merge objects', function () {
    var obj = { a: 1, b: 2 }
    var proto = { b: 3, c: 4 }
    var mergeObj = setPrototypeOf(obj, proto)

    if (Object.getPrototypeOf) {
      assert.strictEqual(Object.getPrototypeOf(obj), proto)
    } else if ({ __proto__: [] } instanceof Array) {
      assert.strictEqual(obj.__proto__, proto)
    } else {
      assert.strictEqual(obj.a, 1)
      assert.strictEqual(obj.b, 2)
      assert.strictEqual(obj.c, 4)
    }
    assert.strictEqual(mergeObj, obj)
  })
})