Jest: Jest cannot use ts-jest when installed globally

[qwertie]

🐛 Bug Report

I can run tests with a local install...

npm install --save-dev jest ts-jest typescript

But a global install causes this error when jest is executed:

● Validation Error:
  Module ts-jest in the transform option was not found.

(This occurs even if ts-jest, but not jest, is installed locally in the project.)

To Reproduce

• Run these terminal commands (including install of babel-core to avoid a "peer dependency" warning):

  mkdir temp
  cd temp
  npm init -f
  npm install --global jest ts-jest typescript babel-core
  

• Add package.json configuration for ts-jest:

  "jest": {
  "transform": {
  "^.+\.tsx?$": "ts-jest"
  },
  "testRegex": "(/__tests__/.*|(\.|/)(test|spec))\.(jsx?|tsx?)$",
  "moduleFileExtensions": ["ts","tsx","js","jsx","json"]
  }

• Run jest to get "Module ts-jest in the transform option was not found."

Expected behavior

If the error does not occur, the output is "No tests found"

Run npx envinfo --preset jest

npx: installed 1 in 2.921s

  System:
    OS: Windows 10
    CPU: x64 Intel(R) Core(TM) i5 CPU         750  @ 2.67GHz
  Binaries:
    npm: 6.1.0 - C:\Program Files\nodejs\npm.CMD

[SimenB]

This is a bug with ts-jest, not us - that's a custom error they throw. If you open up an issue over there and they disagree, we can take another look on our side :)

[GeeWee]

Can you clarify @SimenB ? "Module ts-jest in the transform option was not found." is definitely not an error that ts-jest is throwing. (I grepped our codebase to make sure) - are you sure this is not an error thrown by jest when it can't find the specified preprocessor?

[bowlwinkle]

Updating the package.json transform location worked for me; hope this helps

"^.+\\.tsx?$": "<rootDir>/node_modules/ts-jest/preprocessor.js"

[dan-grayson]

Ensuring that jest was installed locally resolved this issue for me as well. Seems like another piece of evidence that a global install of jest may be part of the cause.

npm install --save-dev jest

[chenop]

What solved for me was the path to babel-jest in the "transform" key inside the jest.config.js file -

transform: {
    "\\.js$": "../node_modules/babel-jest" 
}

Change it to:

transform: { . 
    "\\.js$": "<rootDir>/node_modules/babel-jest" // Use <rootDir> . 
 },