javascript - 无法模拟模块中的函数

Question

我正在尝试为模块创建一个简单的测试。我在一个模块中得到了一些 firestore 触发器(请参阅下面的模块文件)。在 onDelete 触发器中，我只想测试是否调用了 deleteColletion。为此，我只需要模拟 deleteCollection 函数。在我的测试中(请参阅测试文件中的 onDelete 还应删除子集合路径和下载)我模拟了 deleteCollection 函数并调用 firestore 触发器并检查是否 deleteCollection 被调用。这是我从测试中得到的失败响应:

Error: expect(jest.fn()).toBeCalled()

Expected number of calls: >= 1
Received number of calls:    0

jest 似乎与我模拟的函数不匹配。我做错了什么？

注意!我现在认为这个测试本身并不是一个好的测试；)

测试文件

const functions = require('firebase-functions-test');
const admin = require('firebase-admin');
const triggers = require("../../data/protocol/triggers");
const {createEvent} = require("../test_utilities");
const testEnv = functions();


const mockUpdate = jest.fn();
mockUpdate.mockReturnValue(true);

jest.mock("firebase-admin", () => ({
        initializeApp: jest.fn(),
        firestore: () => ({
            batch: jest.fn(() => ({commit: jest.fn()})),
            collection: () => (
                {
                    doc: () => ({update: mockUpdate}),
                    orderBy: () => ({
                        limit: jest.fn(() => ({
                            get: jest.fn(() => ({
                                size: 0,
                                docs: {
                                    forEach: jest.fn(),
                                }
                            }))
                        }))
                    })
                }
            )
        }),
    })
);

jest.mock('../../data/protocol/triggers', () => ({
        ...(jest.requireActual('../../data/protocol/triggers')),
        deleteCollection: jest.fn(() => [])
    })
);


describe("Protocol trigger", () => {
    let adminStub, triggersStub, api;
    const context = {
        params: {
            protocolId: 0,
        }
    };

    beforeAll(() => {
        adminStub = jest.spyOn(admin, "initializeApp");
        //triggersStub = jest.spyOn(triggers, 'deleteCollection');
        api = require("../../index");
    });

    beforeEach(() => jest.clearAllMocks());

    afterAll(() => {
        adminStub.mockRestore();
        //triggersStub.mockRestore();
        testEnv.cleanup();
    });


   ...

    it('`onDelete` should also delete the sub-collections `trails` and `downloads`', async () => 
    {
        const onDeleteProtocol = testEnv.wrap(api.onDeleteProtocol);
        const event = {id: 0};

        await onDeleteProtocol(event, {});

        expect(triggers.deleteCollection).toBeCalled();
        expect(onDeleteProtocol(event, {})).toBe([]);


    });
});

模块

const functions = require('firebase-functions');
const admin = require('firebase-admin');
const {lastModifiedNeedsUpdate} = require("../utilities/event");

function deleteCollection(db, collectionPath, batchSize) {
    return deleteQueryBatch(db, db.collection(collectionPath).orderBy('__name__').limit(batchSize), batchSize, []);
}

...

const deleteProtocol = () => functions.firestore
    .document('protocols/{protocolId}')
    .onDelete((event, context) => {
        return deleteCollection(admin.firestore(), `protocols/${event.id}/trails`, 1);
    });


module.exports = {
    deleteProtocol,
    createProtocol,
    updateProtocol,
    deleteCollection,
};

-- 弗罗德

Answer 1

我通过将辅助函数(deleteCollection 和 deleteQueryBatch)移动到它自己的模块中并模拟该模块来解决这个问题。

--弗罗德