Jest TypeError: Cannot read property 'useFakeTimers' of undefined

idisblueflash · December 28, 2021, 2:49am

Describe the issue/error/question

run a unit test under packages/nodes-base got failed.
But I can fix it by remove node_models and reinstall again with npm install

Steps to reproduce?

clone n8n repo
lerna bootstrap --hoist
npm run build
add the code below under packages/nodes-base/test/nodes/Stripe/helpers.test.js

beforeAll(() => {
	jest
		.useFakeTimers('modern')
		.setSystemTime(new Date('2021-02-18 12:24:00'));

});

What is the error message (if any)?

TypeError: Cannot read property ‘useFakeTimers’ of undefined

Share the output returned by the test

PASS test/nodes/Postgres/Postgres.node.functions.test.js
FAIL test/nodes/Stripe/helpers.test.js
  ● adjustMetadata › it should adjust multiple metadata values

    TypeError: Cannot read property 'useFakeTimers' of undefined

      3 | beforeAll(() => {
      4 | 	jest
    > 5 | 		.useFakeTimers('modern')
        | 		 ^
      6 | 		.setSystemTime(new Date('2021-02-18 12:24:00'));
      7 |
      8 | });

      at Object.useFakeTimers (../../node_modules/jest/node_modules/jest-runtime/build/index.js:1751:38)
      at Object.<anonymous> (test/nodes/Stripe/helpers.test.js:5:4)

PASS test/placeholder.test.ts

Information on your n8n setup

Running n8n via [Docker, npm, n8n.cloud, desktop app]: npm

ivov · December 28, 2021, 5:09pm

Thanks for your report.

For reference, the issue seems to be mismatched versions of @jest/fake-timers.

github.com/vuejs/vue-cli

Using Jest's fakeTimers in modern mode breaks when also depending on @vue/cli-plugin-unit-jest

opened 09:59PM - 28 Jan 21 UTC

Robin-Hoodie

### Version 4.5.11 ### Reproduction link [https://github.com/Robin-Hoodie/t…est-jest-modern-faketimers](https://github.com/Robin-Hoodie/test-jest-modern-faketimers) ### Environment info ``` System: OS: macOS 11.1 CPU: (12) x64 Intel(R) Core(TM) i7-8850H CPU @ 2.60GHz Binaries: Node: 15.0.1 - ~/.nvm/versions/node/v15.0.1/bin/node Yarn: 1.22.5 - ~/.yarn/bin/yarn npm: 7.0.3 - ~/.nvm/versions/node/v15.0.1/bin/npm Browsers: Chrome: 88.0.4324.96 Edge: 88.0.705.53 Firefox: 84.0.2 Safari: 14.0.2 npmPackages: @vue/cli-plugin-unit-jest: ^4.5.11 => 4.5.11 @vue/cli-shared-utils: 4.5.11 jest-serializer-vue: 2.0.2 vue-jest: 3.0.7 vue-template-es2015-compiler: 1.9.1 npmGlobalPackages: @vue/cli: Not Found ``` ### Steps to reproduce - Clone repo - Run command "yarn jest" ### What is expected? Using Jest's `fakeTimers` in modern mode should work (https://jestjs.io/blog/2020/05/05/jest-26#new-fake-timers) ### What is actually happening? An error is thrown: "TypeError: setSystemTime is not available when not using modern timers" --- I'm honestly not sure whether this is a Jest issue, a Vue CLI issue or a Yarn issue. This can be fixed by removing the dependency on `@vue/cli-plugin-unit-jest` entirely, though that's obviously not ideal. It seems that somehow, running `jest` while having a dependency on `@vue/cli-plugin-unit-jest` will still use `jest@24` Even overwriting the `jest@24` dependency to `jest@26` using [Yarn resolutions](https://classic.yarnpkg.com/en/docs/selective-version-resolutions/) does not fix the issue. I bumped into this while working on a monorepo where I have have 2 sub packages in my workspace: - A server package in which tests are run with `jest` - A client (Vue) package in which tests are run with `vue-cli-service test:unit` (The error message is slightly different there, logging "TypeError: Cannot read property 'useFakeTimers' of undefined", though the root cause is likely the same) EDIT: Just found out that installing dependencies with `npm i` (first removing `yarn.lock` and `node_modules`) will actually also fix this (though that doesn't convince me yet that this is a yarn issue) EDIT#2: Using yarn 2 to install dependencies also removes this problem

github.com/facebook/jest

setSystemTime and getRealSystemTime always throw if yarn/npm does not deduplicate @jest/fake-timers

opened 06:44AM - 14 Jul 21 UTC

closed 10:02AM - 15 Oct 21 UTC

simon-paris

Needs Triage Bug Report

## 🐛 Bug Report Jest relies on yarn/npm to deduplicate `@jest/fake-timers`. I…f it is not deduplicated, the following functions always throw the error `setSystemTime is not available when not using modern/legacy timers`. * setSystemTime * getRealSystemTime * runAllImmediates It's caused by the instanceof checks in this file: https://github.com/facebook/jest/blob/master/packages/jest-runtime/src/index.ts. I've attached my real yarn lock file to prove that deduplication can fail in the wild, and not just in the contrived example below. [yarn.lock.zip](https://github.com/facebook/jest/files/6814044/yarn.lock.zip) ## To Reproduce Run the following ``` yarn add [email protected] @jest/[email protected] echo "jest.useFakeTimers('modern').setSystemTime(new Date());" > test.js yarn jest ``` It will output this: ``` FAIL ./test.js ● Test suite failed to run TypeError: setSystemTime is not available when not using modern timers > 1 | jest.useFakeTimers('modern').setSystemTime(new Date()); | ^ 2 | at Object.setSystemTime (node_modules/jest-runtime/build/index.js:1989:17) at Object.<anonymous> (test.js:1:1) ``` ## Expected behavior Jest should not rely on yarn/npm deduplication behavior. ## Link to repl or repo (highly encouraged) Just run the script above in an empty folder. ## envinfo  ``` System: OS: macOS 10.15.7 CPU: (8) x64 Intel(R) Core(TM) i7-8569U CPU @ 2.80GHz Binaries: Node: 14.17.3 - /usr/local/bin/node Yarn: 1.22.10 - /usr/local/bin/yarn npm: 6.14.13 - /usr/local/bin/npm npmPackages: jest: 27.0.3 => 27.0.3 ```

Cannot look more deeply into this at the moment. Could you install try installing @jest/fake-timers in packages/nodes-base and switch back to the legacy implementation in the meantime?