message: test(discriminators): update test to match typegoose specifications
diff: -import { LeanDocument } from 'mongoose';
  import { assertion } from '../../src/internal/utils';
  import {
  DocumentType,
  @@ -104,7 +103,7 @@ it('should pass all mongoose discriminator tests', async () => {
  discriminatorKey: 'kind',
  },
  })
  - @Pre('validate', (next) => {
  + @Pre('validate', function (next) {
  ++eventValidationCalls;
  next();
  })
  @@ -115,7 +114,7 @@ it('should pass all mongoose discriminator tests', async () => {
  public time?: Date;
  }
  - @Pre('validate', (next) => {
  + @Pre('validate', function (next) {
  ++clickedLinkEventValidationCalls;
  next();
  })
  @@ -172,7 +171,7 @@ it('should pass all mongoose discriminator tests', async () => {
  // https://mongoosejs.com/docs/discriminators.html#using-discriminators-with-model-create
  const events = await Promise.all([
  - EventModel.create<LeanDocument<ClickedLinkEvent>>({ time: new Date(Date.now()), url: 'google.com' }),
  + EventModel.create<mongoose.LeanDocument<ClickedLinkEvent>>({ time: new Date(Date.now()), url: 'google.com' }),
  ClickedLinkEventModel.create({ time: Date.now(), url: 'google.com' }),
  SignedUpEventModel.create({ time: Date.now(), user: 'testuser' }),
  ]);
  @@ -202,7 +201,7 @@ it('should pass all mongoose discriminator tests', async () => {
  expect(clickedEvents[0].url).toEqual('google.com');
  // https://mongoosejs.com/docs/discriminators.html#discriminators-copy-pre-and-post-hooks
  - expect(eventValidationCalls).toEqual(3);
  + expect(eventValidationCalls).toEqual(3); // hooks should be triggered for each of the 3 "create" calls of the 3 models above
  expect(clickedLinkEventValidationCalls).toEqual(1);
  // https://mongoosejs.com/docs/discriminators.html#embedded-discriminators-in-arrays
  