jest can't find babel when i'm using gitDir

[bmsuseluda]

Hello okonet,
thank you for your great work.
I'm trying to use jest with lint staged, but when i'm using the "gitDir" option jest can't find babel-jest and so every test fails.

My config:

{
    "gitDir": "../",
    "linters": {
        "*.js": [
            "prettier --single-quote --trailing-comma all --write",
            "git add",
            "eslint --ignore-path ./gui/.gitignore",
            "jest --config ./gui/jest.json --bail --findRelatedTests"
        ],
        "*.css": [
            "stylelint"
        ]
    }
}

My folder structure:
gitFolder -> gui (frontend-app)

^^^^^^ SyntaxError: Unexpected token import at transformAndBuildScript (gui/node_modules/jest-runtime/build/transform.js:320:12)

I think the problem is that jest can't find babel-jest, because of the "gitDir"-option and so can't transform the import statement.

When i'm using jest without lint-staged it's working like a charm.

lint-staged: 3.4.0
jest: 19.0.2
babel-jest: 19.0.0
husky: 0.13.3

I hope you've got an idea where the problem comes from.
Thank you

[okonet]

I'm not sure how this can cause this issue. Probably a way how Jest resolves babel-jest?

[bmsuseluda]

When i'm using the following option in my jest.json jest finds babel-jest:

"transform": {
    "^.+\\.js?$": "./gui/node_modules/babel-jest"
  },

the default for this in jest is:

"transform": {
    "^.+\\.js?$": "babel-jest"
  },

But now every other option in my jest.json points at the gitFolder and not the subfolder gui.
I was playing with the jest option "rootDir" to solve this, but than, jest can't resolve the files from lint-staged.

Correct me if i'm wrong: I think a general problem with "gitDir" is, that the linters will be executed in the gitDir and not in the frontend-app (npm project).
You can see this problem in my eslint config aswell:
"eslint --ignore-path ./gui/.gitignore" instead of "eslint --ignore-path .gitignore"

[okonet]

AFAIK executables should be located relative to package.json and node_modules directory in order to work but all paths provided to them are absolute to make gitDir option work but since I'm not using this option myself I might be wrong.

[bmsuseluda]

I made another test to isolate the problem. I put the jest config in my package.json, so that i don't need the config-parameter and removed every linting tool, but jest.
My config is than:

{
    "gitDir": "../",
    "linters": {
        "*.js": [
            "jest --findRelatedTests"
        ]
    }
}

The result is that jest can't find my config at all:

TypeError: Cannot read property 'config' of null
    at loadFromPackage.then ([path removed for issue report]/app/gui/node_modules/jest-config/build/index.js:50:38)

[okonet]

Can you add "verbose": true after gitDir to get more output? Can you also check out how is jest got called? Another idea to try: create a script `"run-jest": "jest --findRelatedTests" and use it in the config instead of calling jest directly.

[okonet]

Can you create a GH repo with this setup so I can play around with it?

[bmsuseluda]

The idea to call a npm-script instead of jest directly was a good one. It's working =D
Now all jest internal parameters got the right path.
Thank you very much.

[okonet]

Great. It would be still good to get to the root cause so if you can invest some time into it it would be great!

[bmsuseluda]

https://github.com/bmsuseluda/lintStagedJestTest/tree/master/gui
Here you can find a simple project with just 1 snapshot test. If you change the test you can see the problem with npm run precommit

[okonet]

I believe this line makes it behave like this: https://github.com/okonet/lint-staged/blob/master/src/runScript.js#L14

[DeFuex]

hi @bmsuseluda , i don't know if the issue still persists, but i'm not getting the problem by changing the included test and running npm run precommit...is there any step i might have forgotten to get to the problem?

[bmsuseluda]

Hi @DeFuex,
in the test i recommend to change the button id to something different for example "fooBar".
After changing the test you have to add the change to git with git add . before you are running npm run precommit. This is necessary for lint-staged to see the edited files.

[bmsuseluda]

Hi @okonet thanks for the commit. In my opinion it's better to reverse the algorithm from
res.bin !== 'npm' && options && options.gitDir ? { cwd: options.gitDir } : {}
to
res.bin === 'git' && options && options.gitDir ? { cwd: options.gitDir } : {}
so every execution i can do in the package.json would work in lintStaged.
Just the git executions like git add need the gitDir option.

[DeFuex]

@bmsuseluda yeah, im a little bit tired today, seeing the issue now. had some other difficulties 😄

[okonet]

@bmsuseluda good idea! Do you or @DeFuex mind creating a PR for it? I'd add a long-ish comment explaining why it's needed. This should go away when #75 is done (if it's even possible, I still don't know)

[bmsuseluda]

@okonet thanks, i will do it tomorrow.