Timestamps Initialisation Error with InsertMany and Discriminators

[MouadBelbah]

Prerequisites

• I have written a descriptive issue title
• I have searched existing issues to ensure the bug has not already been reported

Mongoose version

6.4.6

Node.js version

16.15.1

MongoDB server version

5.0.9

Description

Nested schema with a {timestamps: true} inside a schema that is a Discriminator will fail to initialise timestamps with insertMany() while successfully inserting the same object with create().

Removing {timestamps: true} from the nested schema seems to fix the problem.

Steps to Reproduce

const { Schema, model, connect, connection } = require('mongoose')

const AssetSchema = new Schema(
  {
    url: {
      type: String,
    },
    size: {
      type: String,
    },
  },
  { timestamps: true }
)

const HeaderSectionSchema = new Schema({
  title: {
    type: String,
  },
  image: AssetSchema,
})

// Abstract section
const BaseSectionSchema = new Schema(
  {
    isVisible: { type: Boolean, default: true },
  },
  { discriminatorKey: 'kind' }
)

// Main Schema
const PageSchema = new Schema(
  {
    sections: [BaseSectionSchema], // Same error without the array "sections: BaseSectionSchema"
  },
  { collection: 'page', timestamps: true }
)

const HEADER_SECTION_KIND = 'header'

const sections = PageSchema.path('sections')
sections.discriminator(HEADER_SECTION_KIND, HeaderSectionSchema)

const Page = model('Page', PageSchema)

const seed = [
  {
    sections: {
      isVisible: true,
      kind: HEADER_SECTION_KIND,
      title: 'h1',
    },
  },
  {
    sections: {
      title: 'h2',
      isVisible: true,
      kind: HEADER_SECTION_KIND,
    },
  },
]

async function run() {
  await connect(
    'mongodb://localhost:27017/db'
  )
  // Inserts the document successfully
  const p1 = await Page.create(seed[0])
  console.log(p1)

  // Fails instantiating the timestamps
  // NOTE: Removing {timestamps:true} from Assets schema will fix this.
  await Page.insertMany(seed)

  await connection.dropDatabase()
  await connection.close()
}

run()

Error Stack Trace

TypeError: Cannot read properties of undefined (reading 'now')
    at EmbeddedDocument.schema.methods.initializeTimestamps (/Users/mb/app/sandbox/node_modules/mongoose/lib/helpers/timestamps/setupTimestamps.js:56:29)
    at model.schema.methods.initializeTimestamps (/Users/mb/app/sandbox/node_modules/mongoose/lib/helpers/timestamps/setupTimestamps.js:72:18)
    at /Users/mb/app/sandbox/node_modules/mongoose/lib/model.js:3363:20
    at Array.map (<anonymous>)
    at /Users/mb/app/sandbox/node_modules/mongoose/lib/model.js:3358:38
    at /Users/mb/app/sandbox/node_modules/mongoose/lib/helpers/parallelLimit.js:49:16
    at /Users/mb/app/sandbox/node_modules/mongoose/lib/model.js:3332:9
    at /Users/mb/app/sandbox/node_modules/mongoose/lib/helpers/promiseOrCallback.js:25:16
    at /Users/mb/app/sandbox/node_modules/mongoose/lib/document.js:2458:7
    at complete (/Users/mb/app/sandbox/node_modules/mongoose/lib/document.js:2816:5)

Expected Behavior

No response