vercel / vercel/next.js

Nextjs with jest example will not work if there is an esm dependency in node_modules

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bug
Dominant language
JavaScript
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Description

Verify canary release
  • I verified that the issue exists in the latest Next.js canary release
Provide environment information
Operating System:
  Platform: linux
  Arch: x64
  Version: #1 SMP Fri Apr 2 22:23:49 UTC 2021
Binaries:
  Node: 16.16.0
  npm: 8.11.0
  Yarn: 1.22.19
  pnpm: N/A
Relevant packages:
  next: 12.2.5
  eslint-config-next: 12.2.5
  react: 18.2.0
  react-dom: 18.2.0
Which example does this report relate to?

https://nextjs.org/docs/testing

What browser are you using? (if relevant)

No response

How are you deploying your application? (if relevant)

No response

Describe the Bug

If you have a project with a dependency that is published as an es modules in node_modules, running jest will not work..even though nextjs works with it e.g. running the project normally with npm run dev.

Test does not run even if ignoring the package. Please check this repo that reproduce the problem:

https://github.com/wmira/banana/

if you run npm run dev here..works fine.. npm run test here does not and this follow the jest example.

Expected Behavior

running test via jest works as per the docs

To Reproduce

repo is below:
https://github.com/wmira/banana/

  1. npm run dev -- nextjs works fine with an es module dependency under node_modules
  2. npm run test -- throws error

Contributor guide

Open the contributing guide

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start by reproducing the failure in the linked banana repository with npm run test, then compare it with npm run dev and the Next.js testing documentation example. Done means the documented Jest example runs successfully when a dependency published as an ES module is present in node_modules.

Written by the indexing model from the issue text.

Assessment

Tech stack
javascript, nextjs
Domain
testing-qa, web-dev
Issue type
Bug
Difficulty
3/5
Estimated time
1-2 days
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
38/100

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