Jest toMatchObject 与 MongoDB 混淆

Question

I have a test on my mongoose model and while one models' tests are running completly fine, another one which is basically a copy - does not work. And honestly I don't understand the problem. I tried to remove some of the properties or add hardcoded values to really match 100% exactly - but somehow i always get a similar error.

The error. What drives me crazy is that I tried to remove/add the "_id" and the "createdOn" field but at least the "_id" always appear in the error. As said above in another model the test does not complain about the "_id" because I do not validate it there...I just don't get it.

insert › Should save a channel

expect(received).toMatchObject(expected)

- Expected  - 1
+ Received  + 2

@@ -1,8 +1,9 @@
  Object {
+   "_id": "5e962f1dc133d8b92891ddaf",
    "createdBy": "5e962f1dc133d8b92891ddae",
-   "createdOn": Anything,
+   "createdOn": 2020-04-14T21:46:05.907Z,
    "hasAcceptedLegal": false,
    "isActive": true,
    "isPublic": false,
    "members": Array [
      "5e962f1dc133d8b92891ddae",

  48 |     expect(spy).toHaveBeenCalled();
  49 | 
> 50 |     expect(channel).toMatchObject({
     |                     ^
  51 |       name: mockName,
  52 |       createdBy: mockCreatedById,
  53 |       createdOn: expect.anything(),

  at Object.it (test/model/channel.model.test.ts:50:21)

The respective model

import mongoose, { Schema, Document } from "mongoose";
import { IUser } from "./user.model";

export interface IChannel extends Document {
  name: string;
  createdBy: IUser["id"];
  createdOn: Date;
  isActive: boolean;
  isPublic: boolean;
  hasAcceptedLegal: boolean;
  members: [IUser["id"]];
}

const ChannelSchema: Schema = new Schema({
  name: { type: String, required: true },
  createdBy: {
    type: Schema.Types.ObjectId,
    ref: "User",
    required: true,
  },
  createdOn: { type: Date },
  isActive: { type: Boolean, default: true },
  isPublic: { type: Boolean, default: false },
  hasAcceptedLegal: { type: Boolean, default: false },
  members: [
    {
      type: Schema.Types.ObjectId,
      ref: "User",
      required: true,
    },
  ],
});

export default mongoose.model<IChannel>("Channel", ChannelSchema);

The test:

it("Should save a channel", async () => {
    expect.assertions(2);
    let mockName = Faker.company.companyName();
    let mockCreatedById = Types.ObjectId();
    let mockCreatedOn = Date.now();

    const channel: IChannel = new Channel({
      name: mockName,
      createdBy: mockCreatedById,
      createdOn: mockCreatedOn,
      members: [mockCreatedById],
    });
    const spy = jest.spyOn(channel, "save");
    channel.save();

    expect(spy).toHaveBeenCalled();

    expect(channel).toMatchObject({
      name: mockName,
      createdBy: mockCreatedById,
      createdOn: expect.anything(),
      isActive: true,
      isPublic: false,
      hasAcceptedLegal: false,
      members: [mockCreatedById],
    });
  });

Answer 1

just for reference, I found sth. that the returned mongoose object should be converted with ".toJSON()" and then it works, but even then it was having a problem with the "createdOn" field as it seems to be a formatted Date or sth. like this (no string, parenthesis missing). What I finally did now was the following and now it works:

it("Should save a channel (required+defaults)", async () => {
    expect.assertions(2);
    let mockName = Faker.company.companyName();
    let mockCreatedById = Types.ObjectId();
    let mockCreatedOn = new Date();

    const channel: IChannel = new Channel({
      name: mockName,
      createdBy: mockCreatedById,
      createdOn: mockCreatedOn,
      members: [mockCreatedById],
    });
    const spy = jest.spyOn(channel, "save");
    channel.save();

    expect(spy).toHaveBeenCalled();

    expect(channel.toJSON()).toMatchObject({
      _id: expect.anything(),
      name: mockName,
      createdBy: mockCreatedById,
      createdOn: expect.anything(),
      isActive: true,
      isPublic: false,
      hasAcceptedLegal: false,
      members: expect.arrayContaining([mockCreatedById]),
    });
  });