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TypeError: Jest: a transform must export a `process` function.

See original GitHub issue

🐛 Bug Report

To Reproduce

Steps to reproduce the behavior:

Install and configure the latest version of ts-jest according to the docs.
run npx jest
See the error

TypeError: Jest: a transform must export a `process` function.

      at ScriptTransformer._getTransformer (node_modules/@jest/transform/build/ScriptTransformer.js:368:15)
      at ScriptTransformer.transformSource (node_modules/@jest/transform/build/ScriptTransformer.js:444:28)
      at ScriptTransformer._transformAndBuildScript (node_modules/@jest/transform/build/ScriptTransformer.js:586:40)
      at ScriptTransformer.transform (node_modules/@jest/transform/build/ScriptTransformer.js:624:25)

Expected behavior

npx jest works properly

Link to repo (highly encouraged)

Debug log:

Don’t need this yet.

# content of ts-jest.log :

envinfo

System:
    OS: macOS
    Node version: v14.16.0

Npm packages:
    jest: 26.0.0
    ts-jest: 27.0.3
    typescript: 4.3.2
    babel(optional):

Additional context: When I downgrade ts-jest to 26.5.5, everything works perfectly. It seems the recent version of ts-jest breaks the jest command, should we add a process export as the error log said?

Issue Analytics

State:
Created 2 years ago
Comments:12

Top GitHub Comments

7reactions

ahnpnlcommented, Jun 13, 2021

You are not using jest 27. ts-jest major version always goes together with Jest major version.

0reactions

lmiller1990commented, Sep 10, 2021

Can you try @vue/vue3-jest? It’s on alpha 1. https://www.npmjs.com/package/@vue/vue3-jest. Should be working with Jest 27, or at least, that’s the intention (internal tests are passing, but Jest ecosystem is immense).

master for vue-jest now defaults to Jest 27. I think this process API should be correct: https://github.com/vuejs/vue-jest/blob/master/packages/vue3-jest/lib/index.js

Still figuring out Jest 27 and Vue 3 compat is work in progress but should be pretty stable and the main version in Vue CLI soon. There is some work in Vue CLI to make everything work with Jest 27, you might find some useful info here: https://github.com/vuejs/vue-cli/pull/6627

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