Vscode-jest: Debug Jest with current test file doesn't stop at correct breakpoint in VSCode

[trivikr]

_From @trivikr on August 30, 2018 6:48_

🐛 Bug Report

Debug Jest with current test file doesn't stop at correct breakpoint in VSCode

To Reproduce

• Open Jest source code in VSCode (tested in VSCode 1.26.1 on Ubuntu 18.04.1)
• Open any test file (tested with putting breakpoint at on line 28 of is_valid_path.test.js)
• Go to debug mode in VSCode, and click "Debug Jest with current test file"
• Notice that debugger stops at line 22 instead

Screen Recording

Expected behavior

Debugger stops at Line 28

_Copied from original issue: facebook/jest#6918_

[trivikr]

_From @SimenB on August 30, 2018 10:22_

This works in Chrome and IntelliJ, so it's an issue with vs code, not Jest (maybe https://github.com/jest-community/vscode-jest?).

[ahanriat]

Having the exact same issue. Works with Chrome, but not VScode

[connectdotz]

jest uses flow, and vscode uses sourcemaps to debug these transpiled codes. There are a few suggestions on how to debug flow in vscode, such as here.

But for your use case, I found a simple line in .babelrc worked just fine without the full sourcemaps support:

"retainLines": true

[Morikko]

I fixed it by setting "sourceMaps": false, in launch.json

[trivikr]

Thank you @connectdotz, I've posted fix in Jest repo at https://github.com/facebook/jest/pull/6985

Thank you @Morikko for sharing another option. I tried it, but it didn't work in some situations (like with file notify-reporter.test.js)

[trivikr]

The fix was merged in https://github.com/facebook/jest/commit/68eb9a232dcbd4ecf85bb1f0bdad5cb850dff81a

[Morikko]

Yes, I also had trouble with the previous solution. Breakpoints were in the right place but actually executing code at another place.

I added "runtimeArgs": ["-r", "flow-remove-types/register"], to my project configuration (launch.json) but it still doesn't work. My project is not using flow but standard javascript.
I am calling jest from ./node_modules/jest/bin/jest.js.

Did you do other things ?

[trivikr]

This issue was raised in Jest's code base, and it was fixed with adding "runtimeArgs": ["-r", "flow-remove-types/register"] in launch.json in commit https://github.com/facebook/jest/commit/68eb9a232dcbd4ecf85bb1f0bdad5cb850dff81a