[jest-circus] missing fail() method

See original GitHub issue

This might be a known issue, but I could not find an existing issue so creating one here 😊 Also, I guess fail() was a bit of an undocumented feature, but we rely on it in our app for some nice developer experience improvements.

💥 Regression Report

After upgrading to Jest v27 (with jest-circus as default) the fail() method is no longer defined.

ReferenceError: fail is not defined

Last working version

Worked up to version: 26.6.3

Stopped working in version: 27.0.0

Can circumvent in 27.x with testRunner: "jest-jasmine2" in jest.config.js

To Reproduce

Steps to reproduce the behavior:

Open a JS project with jest >= 27.0.0
Write a test that includes a fail() method call
Notice that any tests with a call to fail() might pass (depending on the structure), and you will see a “fail is not defined” error message in Jest v27 with jest-circus (works correctly with jest-jasmine2)

Expected behavior

Expected fail() to work by default, as before, without any changes to jest.config.js.

Link to repl or repo (highly encouraged)

See this repo for example of the regression: https://github.com/Darep/jest-circus-fail-method

Check the branch jasmine where the testRunner is changed and the tests run correctly 🙂

The repo also hilights the way we use fail(), just to give some background info & motivation from our use-case 😄

Run `npx envinfo --preset jest`

Paste the results here:

$ npx envinfo --preset jest
npx: installed 1 in 0.976s

  System:
    OS: macOS 11.4
    CPU: (12) x64 Intel(R) Core(TM) i7-9750H CPU @ 2.60GHz
  Binaries:
    Node: 14.16.1 - ~/n/bin/node
    Yarn: 1.21.1 - ~/n/bin/yarn
    npm: 6.14.12 - ~/n/bin/npm
  npmPackages:
    jest: ^27.0.6 => 27.0.6

Issue Analytics

State:
Created 2 years ago
Reactions:66
Comments:14

Top GitHub Comments

20reactions

srmaguracommented, Sep 18, 2021

As a result of this issue, there is currently a discrepancy between @types/jest, which does define fail, and jest-circus, which does not define fail. Discussion in DefinitelyTyped

As a temporary workaround, you can define your own fail function:

function fail(reason = "fail was called in a test.") {
  throw new Error(reason);
}

global.fail = fail;

13reactions

m-gagnoncommented, Sep 14, 2021

Any update on this? Many of my integration tests are missing the correct messaging now that this is undefined, and its causing a lot of confusion.

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