Keywords in ReferenceIdentifier should be syntax error.

[mysticatea]

From eslint/eslint#6013

On v3.1.0, Acorn succeeds to parse the following code.

let foo = {this};

But this should be syntax error: https://tc39.github.io/ecma262/2016/#prod-ObjectLiteral

PropertyDefinition → IdentifierReference → Identifier → IdentifierName but not ReserevedWord

---

"use strict";

const acorn = require("acorn");
const ast = acorn.parse(
    `
    let foo = {this};
    `,
    {
        ecmaVersion: 6
    }
);

console.log(`acorn v${acorn.version}`);
console.log(JSON.stringify(ast, null, 4));

> node test.js
acorn v3.1.0
{
    "type": "Program",
    "start": 0,
    "end": 27,
    "body": [
        {
            "type": "VariableDeclaration",
            "start": 5,
            "end": 22,
            "declarations": [
                {
                    "type": "VariableDeclarator",
                    "start": 9,
                    "end": 21,
                    "id": {
                        "type": "Identifier",
                        "start": 9,
                        "end": 12,
                        "name": "foo"
                    },
                    "init": {
                        "type": "ObjectExpression",
                        "start": 15,
                        "end": 21,
                        "properties": [
                            {
                                "type": "Property",
                                "start": 16,
                                "end": 20,
                                "method": false,
                                "shorthand": true,
                                "computed": false,
                                "key": {
                                    "type": "Identifier",
                                    "start": 16,
                                    "end": 20,
                                    "name": "this"
                                },
                                "kind": "init",
                                "value": {
                                    "type": "Identifier",
                                    "start": 16,
                                    "end": 20,
                                    "name": "this"
                                }
                            }
                        ]
                    }
                }
            ],
            "kind": "let"
        }
    ],
    "sourceType": "script"
}

[marijnh]

Attached patch should help.

[mysticatea]

I checked this on the current master branch, but this is not fixed yet.
This is about object literals, not object patterns.

Please reopen?

[marijnh]

Ugh, I should not read bug reports before I'm properly awake. Try again with patch 7c4758c

[mysticatea]

Thank you very much for the fast fix!
I confirmed this issue have been fixed.