No --harmony default and no --use_strict possible [feature request]

[damianobarbati]

In different issues is mentioned how jest runs --harmony by default.
I don't see this happening.

• I have the spread/rest operator ... causing a Unexpected token error but node supports it
• explictly calling the jest binary node --harmony --use_strict ./node_modules/.bin/jest I found out jest does not support the "strict" too

imac:graphjql damz$ node --harmony --use_strict --trace-deprecation ./node_modules/.bin/jest
TypeError: 'caller', 'callee', and 'arguments' properties may not be accessed on strict mode functions or the arguments objects for calls to them
    at new CustomError (/Users/damz/Desktop/graphjql/node_modules/errno/custom.js:18:45)
    at createError (/Users/damz/Desktop/graphjql/node_modules/errno/custom.js:42:43)
    at ce (/Users/damz/Desktop/graphjql/node_modules/errno/custom.js:48:12)
    at module.exports (/Users/damz/Desktop/graphjql/node_modules/errno/custom.js:52:25)
    at Object.<anonymous> (/Users/damz/Desktop/graphjql/node_modules/errno/errno.js:312:44)
    at Module._compile (module.js:624:30)
    at Object.Module._extensions..js (module.js:635:10)
    at Module.load (module.js:545:32)
    at tryModuleLoad (module.js:508:12)
    at Function.Module._load (module.js:500:3)

• firing just node --harmony ./node_modules/.bin/jest works fine

Could jest allow for a nodeArguments where we can pass an array of arguments to fire node with?
Could jest support the use_strict node mode?

Versions and config:

    "jest": {
        "bail": true,
        "verbose": true,
        "transformIgnorePatterns": [
            "!node_modules/react-runtime"
        ],
        "setupFiles": [
            "raf/polyfill"
        ],
        "transform": {}
    },

"babel-jest": "^21.2.0",
"eslint-plugin-jest": "^21.2.0",
"jest": "^21.2.1",

[SimenB]

Update to latest version of the babel-preset-jest (might be beta) and rest spread works.

Could jest allow for a nodeArguments where we can pass an array of arguments to fire node with?

Why? You can add them yourself (as you've demonstrated in the OP)

Could jest support the use_strict node mode?

Not sure what we can do about the strict mode, all of Jest's own code is strict already. The error seems to come from errno which we transitively from worker-farm.

[damianobarbati]

@SimenB let me thank you for helping first.
I'm currently testing node-only modules so I actually don't need transpiling: what's missing here?

Ok about the node args: let's just explicitly pass them and call the jest binary directly.

Ok about the strict mode: so it's actually failing because of dependencies not strict-compliant.

[SimenB]

Jest internally uses babel. See #4248 for an explanation (including a workaround) and #4519 for the fix in Jest.

I'm gonna close as this is not actionable for us 🙂 Ping me if you disagree, though!

[damianobarbati]

Oh reading #4519 it looks like the problem is istanbul and not jest: jest --no-cache works while jest --no-cache --coverage fails!
Thanks @SimenB for pointing me to the right direction, I would never spot that xD

But I have the istanbul version you mentioned and my jest is already locally installed (not globally):

imac:graphjql damz$ npm ls istanbul-lib-instrument
[email protected] /Users/damz/Desktop/graphjql
├─┬ [email protected]
│ └─┬ [email protected]
│   └── [email protected] 
└─┬ [email protected]
  └─┬ [email protected]
    ├─┬ [email protected]
    │ └── [email protected]  deduped
    └── [email protected]  deduped

@digitalkaoz did you just fix this installing jest locally to the project? I already have but same error!

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