Object Getter triggers yield to incorrectly parse as YieldExpression #1982

FreeMasen · 2019-07-22T20:26:21Z

When any get property is encountered the context.allowYield property is set to false and not reverted after parsing the getter body. This results in any future yield to be parsed as a yield expression incorrectly.

esprima.parse(`
({get a(){}});
yield;
`)

Expected output

{
  "type": "Program",
  "sourceType": "script",
  "body": [
    {
      "type": "ExpressionStatement",
      "expression": {
        "type": "ObjectExpression",
        "properties": [
          {
            "type": "Property",
            "key": {
              "type": "Identifier",
              "name": "a"
            },
            "computed": false,
            "kind": "get",
            "method": false,
            "shorthand": false,
            "value": {
              "type": "FunctionExpression",
              "id": null,
              "params": [],
              "body": {
                "type": "BlockStatement",
                "body": []
              },
              "generator": false,
              "async": false,
              "expression": false
            }
          }
        ]
      }
    },
    {
      "type": "ExpressionStatement",
      "expression": {
        "type": "Identifier",
        "name": "yield"
      }
    }
  ]
}

Actual output

{
    "type": "Program",
    "body": [
        {
            "type": "ExpressionStatement",
            "expression": {
                "type": "ObjectExpression",
                "properties": [
                    {
                        "type": "Property",
                        "key": {
                            "type": "Identifier",
                            "name": "a"
                        },
                        "computed": false,
                        "value": {
                            "type": "FunctionExpression",
                            "id": null,
                            "params": [],
                            "body": {
                                "type": "BlockStatement",
                                "body": []
                            },
                            "generator": false,
                            "expression": false,
                            "async": false
                        },
                        "kind": "get",
                        "method": false,
                        "shorthand": false
                    }
                ]
            }
        },
        {
            "type": "ExpressionStatement",
            "expression": {
                "type": "YieldExpression",
                "argument": null,
                "delegate": false
            }
        }
    ],
    "sourceType": "script"
}

This is pulled directly from everything.js

Using this file as and example, I was surprised that removing line 84 will cause this to parse differently as they are completely unrelated.

I believe the offending code is located on line 3257 of parser.ts.

I believe the correct path in the ecma262 spec for line 200 would be

FreeMasen · 2019-07-31T20:15:55Z

I think I had a problem originally with my expected and actual json blocks. I have corrected this block to correctly match what I was expecting.

jquery / esprima

Object Getter triggers yield to incorrectly parse as YieldExpression #1982

Object Getter triggers yield to incorrectly parse as YieldExpression #1982

FreeMasen commented Jul 22, 2019 •

edited

FreeMasen commented Jul 31, 2019

jquery / esprima

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Object Getter triggers yield to incorrectly parse as YieldExpression #1982

Object Getter triggers yield to incorrectly parse as YieldExpression #1982

Comments

FreeMasen commented Jul 22, 2019 • edited

Expected output

Actual output

FreeMasen commented Jul 31, 2019

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FreeMasen commented Jul 22, 2019 •

edited