ecmaFeatures.modules conflicts with block-scoped-var

[gmathieu]

When ecmaFeatures.module=true, functions calls before declaration throws a block-scoped-var error. This test is using the default parser v0.24.1 but I believe I've seen something similar using babel-eslint.

(function () {
    fnDeclaredBelow(); // error: fnDeclaredBelow used outside of binding context
})();

function fnDeclaredBelow () {
    return true;
}

Here's the associated .eslintrc. If you switch module to false the above code validates properly.

{
  "env": {
    "es6": true,
  },
  "rules": {
    "block-scoped-var": 2,
    "no-use-before-define": [2, "nofunc"],
    "strict": [2, "never"],
  },
  "ecmaFeatures": {
    "modules": true,
  },
}

[gyandeeps]

@eslint/eslint-team input please.

[nzakas]

@gmathieu what about if modules is false? Is the behavior different?

[mysticatea]

I confirmed this issue, and #3126 fixes this.

(If modules flag is false, both are no errors as expected.)

test.js

(function () {
    fnDeclaredBelow(); // error: fnDeclaredBelow used outside of binding context
})();

function fnDeclaredBelow () {
    return true;
}

.eslintrc

ecmaFeatures:
    modules: true
rules:
    block-scoped-var: 2

Command & Actual

> eslint -v
v1.0.0-rc-3
> eslint test.js

test.js
  3:5  error  "fnDeclaredBelow" used outside of binding context  block-scoped-var

✖ 1 problem (1 error, 0 warnings)

> git log -1
commit 6a77f79f507fddb574a438e9ab29118caeb4d7a8
Author: Toru Nagashima <star.ctor@gmail.com>
Date:   Wed Jul 22 22:38:06 2015 +0900

    Fix: `block-scoped-var` issues (fixes #2253, fixes #2747)
> node bin/eslint.js test.js
>

No errors.

Expected

No errors.

[nzakas]

@mysticatea can you add a test case for this in #3126?

[mysticatea]

@nzakas Sure.