Jest can't find AbortController in node v16.13.0

user_8221175 0
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I am using Jest to run my tests. After an upgrade to Node v16.13.0 (the LTS version) from v12, I got the following error:

ReferenceError: AbortController is not defined

Whereas running the code manually with Node worked fine.

I upgraded all my packages to the newest versions during the upgrade to v16. I had been using a polyfill for a mock AbortController because I was using Node v12 before the upgrade. Node v16 comes with its own AbortController, so I removed the polyfill. I am using TypeScript 4.4.4, in case that's relevant (this is not a TypeScript error).

This error did not occur with the polyfill.

It seems that when Jest runs it is not using the same environment compared to when I manually run my app with Node.

I tried the following:

  • Make Node v16.13.0 the default version using nvm
  • Remove all other versions of Node installed except v16.13.0
  • Run console.log(process.env) at the start of the test and check what Node version is being used -> All references to Node had that same version: 16.13.0.

I've been at this for hours and it seems nobody on the internet has had this problem. Does anyone have any idea what is going on?

jestjs node.js
2 Answers

After more digging I 'fixed' the issue. Simply remove "testEnvironment": "node" (inside "jest": {...}) from your package.json.

I stumbled upon the option to set Jest's testing environment (https://jestjs.io/docs/configuration#testenvironment-string), and I noticed my package.json already contained that setting (under "jest": {...}) and it was set to: "testEnvironment": "node". According to the docs, however, it's the default, so I didn't think anything of it.

Hours later, in a ditch effort of desperation I decided to remove it... And voilà, it solved the problem.

Apparently setting the "testEnvironment" configuration to the same thing as its default changes Jest's running environment, which is very counterintuitive and confusing to me.

Edit: This is caused by Create React App. I compared an empty repo with only jest installed with a CRA repo, which comes with jest. Changing the test command to jest and adding the configuration above triggers the issue. If you use the default react-scripts test command, CRA will not run the tests and give you a big red error that they don't support the "testEnvironment" setting.

user_82211750

I experienced this with node v16.15.0 this when downgrading jest from v27 -> v26. Reverting back to jest v27 fixed this error.

user_139296370
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