Babel-eslint: regression v8.2.2: optional chained properties reported as undefined

[dnalborczyk]

it appears that v8.2.2 is reporting optional chained properties as undefined (works with v8.2.1)

foo?.bar?.foobar

77:15  error  'bar' is not defined     no-undef
77:22  error  'foobar' is not defined  no-undef

[bciach]

I approached same issue however I am using "babel-eslint": "^8.2.1" together with "@babel/plugin-proposal-optional-chaining": "^7.0.0-beta.40". @dnalborczyk could you please tell me what babel plugin you are using? Thanks in advance.

[lordgiotto]

I'm facing the same issue.
I'm using @babel/plugin-proposal-optional-chaining

Thanks for your great work ;)

[lehni]

I am seeing this too. Downgrading back to 8.2.1 resolves the issue for me.

[existentialism]

Ref: https://github.com/babel/babel/pull/7288

We need to now handle OptionalMemberExpressions and OptionalCallExpressions.

Added this to my TODO list if no one gets to it first!

[julien-f]

@existentialism babel/babel#7288 has been resolved, does this mean this can be fixed?

[existentialism]

@julien-f yes, my reference to it was more that it is the cause of the issue, not that I was waiting for it to land. Sorry for not being clear!

[lehni]

Not a surprise given the state of discussions, but just to prevent other from having to test it:

8.2.3 still suffers from this issue.

[conradoramalho]

I downgrade 8.2.1 and this doesn't solves the problem for me. How did you fix it?

[brneto]

I'm using:

ESLint: 4.19.1
Babel: 7.0.0-beta.46
babel-eslint: 8.2.3
@babel/plugin-proposal-optional-chaining: 7.0.0-beta.46

And I having the same issue here.

Have someone found how to solver that?

[gastonmorixe]

hours on this... downgrading to 8.2.1 works for me. Thanks

[hansonw]

It seems like this should be fixed once the babylon dep (@babel/parser now) is upgraded past beta45 (which includes https://github.com/babel/babel/pull/7668). Right now it's at beta44.

Should be a pretty easy bump, is anyone working on this already (@hzoo?)

[lehni]

@hansonw that alone doesn't seem to fix it. I just tried by installing and linking babel-eslint locally, and upgrading its dependencies. I still get the same linting errors with its @babel dependencies updated to beta.48

[brneto]

In fact, downgrading to 8.2.1 have worked. Any idea when this issue will be fixed in next releases?

[brneto]

@lehni have you tried with beta.49?

[richardgirges]

I'm seeing it with beta.49. I too had to downgrade to 8.2.1

[brneto]

@richardgirges Have you seen with beta.49? Did Work?

[LennyPenny]

Even downgrading to 8.2.1 doesn't fix this for me

[brneto]

We need the see your .babelrc and .eslintrc, at least.

[davidsmorais]

Downgraded to 8.2.1 and I got rid of the 'undefined' errors. Now it seems to be expecting a ternary (probably due to the '?').

Here are my dependencies

    "@babel/core": "^7.0.0-beta.49",
    "@babel/plugin-proposal-optional-chaining": "^7.0.0-beta.49",
    "@babel/plugin-syntax-optional-chaining": "^7.0.0-beta.49",
    "@babel/polyfill": "^7.0.0-beta.49",
    "@babel/preset-env": "^7.0.0-beta.49",
    "@babel/preset-react": "^7.0.0-beta.49",
    "babel-eslint": "^8.2.1",
    "babel-loader": "^8.0.0-beta.3",
    "eslint": "^4.19.1",

My .babelrc and .eslintrc, respectively

{
  "presets": [
    "@babel/react",
    "@babel/preset-env"
  ],
  "plugins": [
    "@babel/plugin-proposal-optional-chaining",
    "react-hot-loader/babel"
  ]
}

{
  "parser": "babel-eslint",
  "env": {
    "browser": true,
    "es6": true
  },
  "extends": ["eslint:recommended", "airbnb"],
  "parserOptions": {
    "ecmaFeatures": {
      "experimentalObjectRestSpread": true,
      "jsx": true
    },
    "sourceType": "module"
  },
  "plugins": ["react", "jsx-a11y", "import"],
  "rules": { ... }

[LennyPenny]

@brneto
.babelrc

{
    "presets": [
        [
            "@babel/preset-env",
            {
                "targets": {
                    "node": "current"
                }
            }
        ]
    ],
    "sourceMaps": "inline",
    "plugins": [
        "@babel/plugin-proposal-optional-chaining",
        "import-glob"
    ]
}

.eslintrc

{
    "parser": "babel-eslint",
    "env": {
        "es6": true,
        "node": true
    },
    "extends": "eslint:recommended",
    "parserOptions": {
        "ecmaVersion": 8,
        "sourceType": "module"
    },
    "rules": {...}
}

[brneto]

@LennyPenny Are you importing @babel/polyfill at the root of your code? Are you using webpack or node as the environment to run your code?

[rubennorte]

@existentialism I guess I got to it first. Can you please take a look at #630 where I put a fix for this? This is the last thing we need in order to roll out this at Facebook. Thanks!

[LennyPenny]

@brneto I'm using node with the latest babel. I never needed @babel/polyfill before, but even with it it doesn't work

[lehni]

Unfortunately we're not out of the woods yet: #643

[jlaustill]

@lehni What is the process of helping with this? I'd like to get to a point that I can use optional chaining with eslint and cra@next, but I'm not sure how to plug in to help.

[lehni]

@jlaustill I don't know! I haven't been involved in fixing those issues, just been observing them and pointing them out.

[macrozone]

even with assigments this error gets thrown using babel-eslint 9.0.0 final

https://github.com/babel/babel-eslint/issues/643#issuecomment-417282457

downgrading to 8.2.1 solves it.