Jest giving wrong line number for error

[zwhitchcox]

Do you want to request a feature or report a bug?
Bug report

What is the current behavior?
It gives the line number a few lines above where the error actually is. The error should be on line 7, where Object.assign is run, but it is giving the error on line 10.

Sourcemaps appear to be working, but this particular instance, they didn't for some reason.

I made a repo https://github.com/zwhitchcox/jest-bug, you just have to git clone, yarn install and yarn test

What is the expected behavior?
To give the correct line number

Please provide your exact Jest configuration and mention your Jest, node,
yarn/npm version and operating system.
Node: v8.4.0
Jest: 22.1.4
OS: GalliumOS (basically Ubuntu 14.04)
yarn: 1.1.0

[zwhitchcox]

I also copied my code to the react official example, and it had the same problem

[rickhanlonii]

@zwhitchcox that repo is empty 😬

[zwhitchcox]

Sorry! Just pushed!

[rickhanlonii]

Confirmed - the failure is shown on line 10 but the code is on line 7.

Code:

FWIW converting the exports to commonjs will show the correct line so this is probably babel related:

[jwbay]

Does this repro without jest-sourcemaps? Custom transformers currently can't map stacktraces and code frames against original source code. I would think out-of-the-box babel-jest would work here.

[zwhitchcox]

No, it wasn't working, and I added that thinking it might work

[rickhanlonii]

@zwhitchcox it would be helpful if you could remove everything you can from the test repo

@jwbay I had the same thought, but I tested and it's not related to jest-sourcemaps

[rickhanlonii]

I created the absolute minimum repo: https://github.com/rickhanlonii/jest-issue-5446

See the comment here for an interesting finding:

[zwhitchcox]

Thanks, sorry, I would've done that, but I'm not home right now. And yeah, I think it's probably babel, but Facebook de facto owns anything related to the internet anyway, right??

[SimenB]

Vaguely related to #5449. If I apply the same changes here as I propose in there, this is the error:

[nbkhope]

Hi. I'm using Node 8.9.4 with jest@22.2.1. Given the following example

  test('should fail', () => { // Line 31
    expect(1).toBe(2); // Line 32
  });

  test('should do something else', () => {

  });

  test('should do yet something else', () => {

  }); // Line 41

The test output is:

    expect(received).toBe(expected) // Object.is equality

    Expected value to be:
      2
    Received:
      1

      39 |   test('should do yet something else', () => {
      40 |
    > 41 |   });
      42 |

So the error should be at line 32, but Jest says it is at line 41, a difference of 9.

For babel, I'm using:

    "babel-loader": "^7.1.2",
    "babel-preset-env": "^1.6.1",
    "babel-preset-react": "^6.24.1",

[SimenB]

Can you create a repro showing this?

[SimenB]

@rickhanlonii your example is fixed after #5177. The OP is still wrong, though...