Wrong directive

[neumatho]

Hi,

If you parse the expression "valueOf" in __proto with the Directives option enabled, then a directive property is added to the ExpressionStatement node, which is wrong. The directive property should only be added for "use strict" literals.

Meriyah also adds a BinaryExpression in the expression property, which is not legal according to the AST specification for directives. See https://github.com/estree/estree/blob/master/es5.md#directive

For these two lines:

"use strict";
"valueOf" in __proto

the tree looks like:

{
  "type": "Program",
  "sourceType": "script",
  "body": [
    {
      "type": "ExpressionStatement",
      "expression": {
        "type": "Literal",
        "value": "use strict",
        "raw": "\"use strict\""
      },
      "directive": "use strict"
    },
    {
      "type": "ExpressionStatement",
      "expression": {
        "type": "BinaryExpression",
        "left": {
          "type": "Literal",
          "value": "valueOf",
          "raw": "\"valueOf\""
        },
        "right": {
          "type": "Identifier",
          "name": "__proto"
        },
        "operator": "in"
      },
      "directive": "valueOf"    <!-- this one should be removed
    }
  ]
}

A fix could be that you in the parseDirective() function when checking for the directive option, also test the node type stored in expression variable and only add the directive property if it is a Literal.

-Thomas

[KFlash]

cc @3cp @aladdin-add