A TypeError occurred when mocks BatchResponseContent via jest.spyOn()

[karamem0]

Bug Report

Prerequisites

• Can you reproduce the problem?
• Are you running the latest version?
• Are you reporting to the correct repository?
• Did you perform a cursory search?

For more information, see the CONTRIBUTING guide.

Description

Test failed when I upgraded SDK version from 2.2.1 to 3.0.0.

Console Errors: TypeError: Cannot redefine property: BatchResponseContent

Screenshots:

Steps to Reproduce

1. Create a new project. npm init
2. Install packages.

• @microsoft/microsoft-graph-client@3.0.0
• @types/jest@26.0.24
• jest@26.6.0
• ts-jest@26.5.6
• typescript@4.3.5

3. Write a test script. index.test.ts

import * as microsoftGraph from '@microsoft/microsoft-graph-client';
it('test', () => {
    jest.spyOn(microsoftGraph, 'BatchResponseContent');
});

Expected behavior: Test passed.

Actual behavior: Test failed because cannot mock BatchResponseContent.

Additional Context

It works with @microsoft/microsoft-graph-client@2.2.1. Was it any changes?

Usage Information

Request ID - Value of the requestId field if you are receiving a Graph API error response

SDK Version - 3.0.0

• Node (Check, if using Node version of SDK)

Node Version - 14.17.6

• Browser (Check, if using Browser version of SDK)

Browser Name - [The name of Browser that you are using for SDK]

Version - [The version of the browser you are using]

[nikithauc]

@karamem0 There are no changes to BatchResponseContent in 3.0.0.

[karamem0]

@nikithauc Thank you for replying. Did you try to reproduce the issue? In actual there might be no changes to BatchResponseContent but something causes the error.

[nikithauc]

@karamem0 I was able to reproduce the issue. Will have to look more into this to understand the cause of the issue.

Thank you for reporting this!

Are you able to use the BatchResponseContent otherwise?

[nikithauc]

@karamem0
I came across some similar reported issues:

aelbore/esbuild-jest#26
https://stackoverflow.com/questions/67872622/jest-spyon-not-working-on-index-file-cannot-redefine-property
https://medium.com/walmartglobaltech/jest-v18-to-v23-migration-notes-b726cf6aafcf

The typescript version was updated to version 4.x in @microsoft/microsoft-graph-client@3.0.0. My first thought is this upgrade is causing the issue.

Does the workaround suggested as follows work for you?
https://stackoverflow.com/questions/67872622/jest-spyon-not-working-on-index-file-cannot-redefine-property

[ghost]

This issue has been automatically marked as stale because it has been marked as requiring author feedback but has not had any activity for 4 days. It will be closed if no further activity occurs within 3 days of this comment.

[karamem0]

@nikithauc
Thanks a lot! I understood the reason is the change of typescript build systems.
I will use jest.mock instread of jest.spyOn.

jest.mock('@microsoft/microsoft-graph-client');
import { BatchResponseContent } from '@microsoft/microsoft-graph-client';
it('test', () => {
  const MockBatchResponseContent = BatchResponseContent as unknown as jest.Mock;
  MockBatchResponseContent.mockImplementation(() => ({
    getResponses: jest.fn()
  }));
});

[karamem0]

My suggestion to avoid this error is as follows.

before:

export * from "./content/BatchRequestContent";

after:

export { BatchRequestContent } from "./content/BatchRequestContent";

[nikithauc]

@karamem0 Thanks for bringing this up!

Can you explain the difference here and how that caused the error?

My suggestion to avoid this error is as follows.

before:

export * from "./content/BatchRequestContent";

after:

export { BatchRequestContent } from "./content/BatchRequestContent";

[karamem0]

@nikithauc

If build using export *, the result is like below.

"use strict";
var __createBinding = (this && this.__createBinding) || (Object.create ? (function(o, m, k, k2) {
    if (k2 === undefined) k2 = k;
    Object.defineProperty(o, k2, { enumerable: true, get: function() { return m[k]; } });
}) : (function(o, m, k, k2) {
    if (k2 === undefined) k2 = k;
    o[k2] = m[k];
}));
var __exportStar = (this && this.__exportStar) || function(m, exports) {
    for (var p in m) if (p !== "default" && !Object.prototype.hasOwnProperty.call(exports, p)) __createBinding(exports, m, p);
};
Object.defineProperty(exports, "__esModule", { value: true });
__exportStar(require("./content/BatchRequestContent"), exports);

__exportStar function calls Object.defineProperty function without { configurable: true }. jest.spyOn function tries to overwrite existing property but is blocked.

If build using export {}, the result is like below.

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.BatchRequestContent = void 0;
var BatchRequestContent_1 = require("./content/BatchRequestContent");
Object.defineProperty(exports, "BatchRequestContent", { enumerable: true, get: function () { return BatchRequestContent_1.BatchRequestContent; } });

In this case, the Object.defineProperty function will not be called for the property. jest.spyOn function can overwrite existing property.