Sails.js: Jest spyOn results in TypeError: Cannot assign to read only property

Question

我正在尝试使用 Jest 的 spyOn:

模拟函数调用的实现

await sails.helpers.models.test.randomFn.with({ ... });

const randomFnSpy = jest.spyOn(sails.helpers.models.test.randomFn, 'with');
randomFnSpy.mockImplementation(() => {});

错误：

TypeError: Cannot assign to read only property 'with' of function 'function runFn(_argins, _explicitCbMaybe, _metadata){

我尝试将属性设置为 configurable 和 writable :

Object.defineProperty(
  sails.helpers.models.test.randomFn, 
  'with', 
  { configurable: true, writable: true }
);

错误：

TypeError: Cannot redefine property: with at Function.defineProperty ()

Answer 1

对我来说模拟助手的方法：

Sails 内部使用 machine 执行以下操作：

Object.defineProperty(wetMachine, 'with', {
    enumerable: false,
    configurable: false,
    writable: false,
    value: arginStyle === 'named' ? wetMachine : wetMachine.customize({
      arginStyle: 'named',
      execStyle: execStyle,
      extraArginsTactic: extraArginsTactic,
      extraCallbacksTactic: extraCallbacksTactic,
      arginValidationTactic: arginValidationTactic,
      resultValidationTactic: resultValidationTactic,
      finalAfterExec: finalAfterExec,
      defaultMeta: defaultMeta,
      defaultArgins: defaultArgins,
      // Note there is no reason to pass through `implementationSniffingTactic`
      // here, since it would have already applied now (it applies at build-time.)
    })
  });

不是监视 with，而是嘲笑助手的 fn 成功了：

jest.mock('../../../../../api/helpers/models/test/random-fn', () => ({ fn: () => {} }));

Sails.js: Jest spyOn results in TypeError: Cannot assign to read only property

Sails.js: Jest spyOn results in TypeError: Cannot assign to read only property

javascript

sails.js

jestjs