Jest mock timer warning without using fake timers

[sspenst]

Prerequisites

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

Mongoose version

6.6.0

Node.js version

18.7.0

MongoDB server version

6.5.4

Description

Using jest.spyOn shows the following warning in the console:

(node:35252) [MONGOOSE] Warning: Mongoose: looks like you're trying to test a Mongoose app with Jest's mock timers enabled. Please make sure you read Mongoose's docs on configuring Jest to test Node.js apps: https://mongoosejs.com/docs/jest.html

Steps to Reproduce

Create a test with the following:

jest.spyOn(logger, 'error').mockImplementation(() => ({} as Logger));

For additional context: https://github.com/sspenst/pathology/blob/main/tests/pages/api/avatar/avatar.test.ts#L23

Expected Behavior

No warning should appear in the console.

[hasezoey]

cannot reproduce, this must mean that mock timers are somehow enabled in your tests OR you are not using NodeJS (like deno) and that function somehow does not include nextTick

the line checking for nextTick is defined like:

mongoose/lib/helpers/printJestWarning.js

Line 12 in 94b308e

if (typeof jest !== 'undefined' && process.nextTick.toString().indexOf('nextTick') === -1) {

which i cant get to output anything other than 9 (process.nextTick.toString().indexOf('nextTick')) when both running in NodeJS REPL or in jest test without enableMockTimers set

MongoDB server version 6.5.4

from what i can tell that version does not exist yet

[sspenst]

Sorry I was looking at the wrong MongoDB version, I'm using "node_modules/mongodb": { "version": "4.9.1", ...

But thanks for the code reference, I was able to narrow down the root cause:

const newrelicWinstonFormatter = newrelicFormatter(winston);

Using winston logger with this option causes the output of process.nextTick.toString() to be:

function wrappedProcess() {
  const segment = shim.getActiveSegment()
  if (!segment) {
    return fn.apply(this, arguments)
  }

  // Manual copy because helper methods add significant overhead in some usages
  const len = arguments.length
  const args = new Array(len)
  for (let i = 0; i < len; ++i) {
    args[i] = arguments[i]
  }

  shim.bindSegment(args, shim.FIRST, segment)

  return fn.apply(this, args)
}

Is it correct for printJestWarning to always output a warning if nextTick is overwritten? Maybe the check could be updated to only output a warning if nextTick is equal to Jest's mock timer function.

[sspenst]

I created a PR for what I think the correct fix might be, but feel free to close it if this is not the right solution.