1476321 - SpiderMonkey should throw ReferenceError on invalid left-hand side expression (++ ++)

Status: RESOLVED DUPLICATE of bug 1340307

(Core :: JavaScript Engine, defect)

Description

[cinfuzz]

User Agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/67.0.3396.87 Safari/537.36 OPR/54.0.2952.54

Steps to reproduce:

Hi everyone, 
according to ES6 (https://www.ecma-international.org/ecma-262/8.0/index.html#sec-update-expressions-static-semantics-early-errors), should throw ReferenceError if the expression is not valid on UnaryExpression.

OS: Ubuntu 16.04 x64
version: 62.0b8

var a = 1;
eval('++ ++ a;')


Actual results:

SyntaxError: expected expression, got '++'


Expected results:

ReferenceError: Invalid left-hand side expression in prefix operation (v8)
or
ReferenceError: Prefix ++ operator applied to value that is not a reference (jsc)

Comment 1

[cinfuzz]

V8, Chakra, JSC and XS works as expected.

#### JavaScriptCore
ReferenceError: Prefix ++ operator applied to value that is not a reference.

#### V8
ReferenceError: Invalid left-hand side expression in prefix operation

#### Chakra
ReferenceError: Invalid left-hand side in assignment

#### XS
ReferenceError: no reference

#### SpiderMonkey
SyntaxError: expected expression, got '++':