Error mocking mongoose schema with ts-mockito: “find() is not a function”

[jsoneaday]

I am running typescript with ts-node. I am trying to run a test with mocha and chai. I also tried my test with jest. Basically most of the test runs fine. But when I attempt to mock my mongoose schema model object, I get the error mockThread.find is not a function. Odd thing is when I hover over or dot on the mock object I can see all the mongoose query methods including find. This failure occurs only when the test runs. If I remove the mock and just run my test it succeeds.

import { mock, when, instance } from "ts-mockito"; import { expect } from "chai"; import request from "supertest"; import app from "../../src/app"; import { isJSONString } from "../testHelper"; import { ThreadSchema } from "../../src/repo/models/thread"; import mongoose, { Model, DocumentQuery, Document } from "mongoose";

const Thread = mongoose.model("Thread", ThreadSchema);

describe("Test whether result is array and json stringifyable.", () => { it("Should return the error", done => { let mockThread: Model<Document, {}> = mock<Model<Document, {}>>(Thread); // I've tried adding and removing the typing info above but that did nothing when(mockThread.find()).thenReturn( new DocumentQuery<Document[], Document, {}>() );

request(app) .get("/threads") .expect(200) .end(function(err, res) { expect(isJSONString(res.body)).to.equal(true); expect(Array.isArray(res.body)).to.equal(true); done(); }); }); });

I run the test with this command mocha --require ts-node/register test/**/*.ts

[adietish]

I face the same error with generic objects (no mongoose involved):

I have an RPClient that I retrieve an object Outgoing from (client.getOutgoingHandler(timeout?: number)). In Outgoing, I have a method outgoing.getServerHandles() that returns a promise and that I want to fake and return a predefined answer. The call that I want to mock is in the class under test:

client.getOutgoingHandler().getServerHandles()

To mock things I do the following:

client = mockito.mock(RSPClient);
outgoingMock = mockito.mock(Outgoing);
mockito.when(outgoingMock.getServerHandles(mockito.anyNumber())).thenResolve([serverHandle]);
mockito.when(client.getOutgoingHandler()).thenReturn(outgoingMock);

The test then runs into the following error (looks identical to yours, @dharric):

TypeError: client.getOutgoingHandler(...).getServerHandles is not a function

[dice14u]

First make sure that you are using an instance of the mock not the mock itself, You need to create an instance of the mock not the mock itself mockito.when(client.getOutgoingHandler()).thenReturn(instance(outgoingMock));

[adietish]

@dice14u thx for the quick response. Did not try that yet, I'll get back to ts-mockito when writing the next tests and try to substitute sinon. If that was my error, it would maybe be a great idea to include this hint in the error?