Bug report: Always errors for use strict

[mondwan]

Versions

$ cat package.json
  "devDependencies": {
       "eslint": "~1.10.3",
       "babel-eslint": "~5.0.0-beta6",
        "eslint-plugin-react": "~3.13.1"
  }

.eslintrc

$ cat .eslintrc 
{
  "parser": "babel-eslint",
  "env": {
    "browser": true,
    "node": true,
    "amd": true
  },
  "settings": {
      "ecmascript": 6,
      "jsx": true
  },
  "plugins": [
      "react"
  ],
  "rules": {
    "strict": [2, "global"],
  }
}

a.js

"use strict";

console.log('a.js');

Reproduce error

$ node_modules/.bin/eslint -c .eslintrc a.js 

/home/mondwan/Documents/test/babel_eslint_test/a.js
  3:1  error  Use the global form of "use strict"  strict

✖ 1 problem (1 error, 0 warnings)

Note

• I have tried "use strict", "use strict"; 'use strict' and 'use strict';. None of them work.
• I have tried Babel-eslint v4.1.6. No such bug occur

[jmm]

Thanks for the report! I think this is due to the introduction of the Directive* node types in Babel v6. There are probably 2 solutions: persuade eslint to modify the rule to check for those node types first, or here rework them to the regular AST structure / types that the eslint rule is expecting. BTW, this can be trimmed down to a more minimal reproduction.

[jmm]

I double checked with eslint on their gitter and per nzakas they only want to support ESTree.

[satya164]

I'm also facing this.

[hzoo]

We can definitely change directive to estree b/c that's what we've had to do for everything else anyway. If you are using modules you shouldn't need use strict since they are all in strict mode right?

[satya164]

@hzoo Yeah. My code is a mix of these things right now as I'm running in my tests with Babel and other files with plain Node. I should change to use modules anyways and setup the server to run with babel :D

[jmm]

@hzoo I was wondering what is this line for?:

ast.directives = ast.program.directives;

[hzoo]

I think I was just trying to copy whatever was needed from the babylon AST to estree since it uses File instead of Program but looking at what you posted I wouldn't need to add that line since estree doesn't use that anyway.

[jmm]

@hzoo 👍

[hzoo]

Ok still have to convert Directive to an ExpressionStatement that has a Literal - It's getting pretty annoying to do this manually. Maybe we can use some more babel utilities to make it easier.

[mondwan]

Sorry, I am not sure I can follow the discussion.

Any hints for Directive* node, AST tree, ESTree? And how should I fix this problem? By configuration ?

[hzoo]

The AST is different so we have to convert it in https://github.com/babel/acorn-to-esprima/blob/master/src/toAST.js. Not much you can do other than using a different version or not using the rule.

[mondwan]

Yes. I am using a different version currently. But how to not using the rule?

And I am not sure the meaning of AST and esproma? I guess this is some kind of parsing mechanism? Do you have any links for showing the concept of them?

Thanks very much.

[hzoo]

Oh I just meant turning off the rule "strict": [2, "global"], (although you probably don't want that).

AST: https://en.wikipedia.org/wiki/Abstract_syntax_tree
esprima: http://esprima.org/, https://github.com/jquery/esprima - esprima/babylon/acorn are javascript parsers. Check out http://astexplorer.net/, https://www.youtube.com/watch?v=rKuNbEwoQfQ

You'll just have to wait for a fix.

[mondwan]

Thanks. I will check them out later on.

[jmm]

@hzoo

Ok still have to convert Directive to an ExpressionStatement that has a Literal - It's getting pretty annoying to do this manually. Maybe we can use some more babel utilities to make it easier.

It is a bit annoying, but it shouldn't be too bad. Want me to take a crack at it? (I sort of already did it before just to test things out.)

[jmm]

WIP fix for this: babel/acorn-to-esprima@master...jmm:directives. I believe acorn-to-esprima is the correct home for this, right?

[hzoo]

Yeah. Also, all that code needs cleanup - would be nice to be able to use more babel methods instead of stuff like

[d6u]

FYI, strict: [2, 'function'] behaves like what strict: [2, 'global'] intended to do.

[jmm]

@hzoo Thanks.

would be nice to be able to use more babel methods instead of stuff like

Hmm, I probably don't actually know the Babel method for that as of yet.

Submitted #241 for this.

@d6u I'm not sure what you mean.

[jmm]

Huh, so putting "Fixes {{someuser}}/{{somerepo}}#123" in a PR in a different repo closes the referenced issue when merged? Maybe just if they're under the same org?

[hzoo]

Yeah since you have colloborator access to the org

[jmm]

Oh ok, I'll have to be more careful with that. But since you merged and published babel/acorn-to-esprima#5 it is fixed now ✨.

[hzoo]

Fixed with https://github.com/babel/babel-eslint/releases/tag/v5.0.0-beta7