Javascript 在使用Jest进行测试时，在Express应用程序中未定义Multer

我正在使用JEST测试我用TS制作的Express应用程序，它使用Multer上传文件.但我的测试以错误"TypeError: Cannot read properties of undefined (reading 'diskStorage')"结束. 这个应用运行得很好，错误只出现在我测试的时候.

我的错误发生在-

import multer from "multer";

const storage = multer.diskStorage({
    destination: function (req, file, cb) {
        cb(null, "images/");
    },
    filename: function (req, file, cb) {
        const uniqueSuffix = Date.now() + "-" + Math.round(Math.random() * 1e9);
        cb(
            null,
            (
                file.fieldname +
                "-" +
                uniqueSuffix +
                "-" +
                file.originalname
            ).replace(/ /g, "_")
        );
    },
});

function filter(req: object, file: Express.Multer.File, cb: Function) {
    cb(null, file.mimetype === "image/jpg" || file.mimetype === "image/jpeg");
}

const postStorage = multer({
    storage: storage,
    fileFilter: filter,
    limits: {
        fileSize: 1024 * 1024, // max size in bytes
    },
});

export default postStorage;

然后我在我的航线上用它-

const router = express.Router();

router.get("/", getAll);
router.post(
    "/",
    postStorage.fields([
        { name: "main_image", maxCount: 1 },
        { name: "additional_images", maxCount: 5 },
    ]),
    RequestValidator(PostSchema, "body"),
    insert
);

export default router;

我的jest密码是-

describe("do ", () => {
    describe("dodo", () => {
        it("dododo", async () => {
            await supertest(app).get("/").expect(200);
            return true;
        });
    });
});

如果能有任何帮助，我将不胜感激.谢谢.