VS Code not recognizing Jest, underlining with Intellisense

Question

I'm using VS Code in a Typescript project that uses Jest for testing. For some reason, VS Code thinks that the Jest globals are not available:

I have the Jest typedefs installed in my dev dependencies.

"devDependencies": {
    // ...truncated
    "@types/jest": "^20",
    "jest": "^20.0.4",
    "ts-jest": "^20.0.7",
    "ts-node": "^5.0.0",
    "typescript": "~2.4.0"
}

I have tried to make `npm i @types/jest` and VSCode discovered `jest` global object. Try to reinstall/restart/clear cache... — Pavel, Mar 31 '18 at 19:43
It may be a silly question, but did you import the objects you're using? Also, this question may help: https://stackoverflow.com/questions/41324636/how-to-import-jest — Gustavo Lopes, Apr 01 '18 at 00:59
Jest is setup as a global object so as to not need to import those functions in every test file. — Steven Musumeche, Apr 02 '18 at 13:50

score 10 · Answer 1 · answered May 02 '18 at 08:50

10

Correct answer here is that typescript requires type declarations for jest before jest global objects are visible for intellisense.

Add this triple-slash directive to beginning of your test file:

/// <reference types="jest" />

answered May 02 '18 at 08:50

Licensed Slacker

378
1
9

score 3 · Answer 2 · answered Apr 13 '20 at 18:45

I've similarly struggled with this problem a number of times despite having @types/jest in my devDependencies too.

I created jest-without-globals as a very tiny wrapper to support importing Jest's features instead of relying on globals, thereby ensuring the variables exist.
It's written in TypeScript as well, ensuring that it's typed properly when imported and that you don't need to do anything other than an import to make the types function.

Per the Usage docs, it's straightforward to use:

import { describe, it, expect } from 'jest-without-globals'

describe('describe should create a section', () => {
  it('it should checkmark', () => {
    expect('').toBe('')
   })
})
All of the functions available in Jest's API, as well as jest and expect, can be imported from jest-without-globals.

score 0 · Accepted Answer · answered Apr 02 '18 at 13:51

0

I upgraded my version of Typescript to 2.8 and this problem went away. I'm going to assume it was some sort of cache issue.

answered Apr 02 '18 at 13:51

Steven Musumeche

2,886
5
33
55

1

I have seen that using the "Restart TS Server" command from Cmd+Shift+P can help sometimes. Ensuring my tsconfig file was being loaded and had the correct settings was also important, as was this post: https://stackoverflow.com/questions/57874114/intellisense-for-jest-not-working-in-vs-code – killthrush Nov 23 '21 at 21:25

VS Code not recognizing Jest, underlining with Intellisense

3 Answers3