Error when using VM

[flyerH]

Describe the bug

JSONPath fails in VM mode (eval: 'safe') but works in native mode.

Code sample or steps to reproduce

$..parameters..[?(@property !== 'properties' && @.example !== void 0 && (@.type || @.format || @.$ref || @.properties || @.items))]

{
    "components": {
        "schemas": {
            "QueryCallbackResponse": {
                "properties": {
                    "num_out": {
                        "description": "description",
                        "example": 123123123,
                        "format": "int32",
                        "title": "title",
                        "type": "integer"
                    }
                },
                "type": "object"
            }
        }
    },
    "openapi": "3.0.0",
    "paths": {
        "/brand/sample/querycallback": {
            "get": {
                "description": "description",
                "operationId": "CallbackTesting",
                "parameters": [
                    {
                        "description": "description",
                        "in": "query",
                        "name": "num_in",
                        "required": false,
                        "schema": {
                            "description": "description",
                            "example": 123123123123,
                            "format": "int32",
                            "title": "title",
                            "type": "integer"
                        }
                    }
                ],
                "responses": {
                    "200": {
                        "content": {
                            "application/json": {
                                "schema": {
                                    "$ref": "#/components/schemas/QueryCallbackResponse"
                                }
                            }
                        },
                        "description": "description"
                    }
                }
            }
        }
    }
}

Console error or logs

Figure 1: JSONPath failure under VM (eval: 'safe')

Figure 2: Expected JSONPath result in native mode

Expected behavior

Expected result

[
  {
    "description": "description",
    "example": 123123123123,
    "format": "int32",
    "title": "title",
    "type": "integer"
  }
]

Environment (IMPORTANT)

• JSONPath-Plus version: 10.3.0

Desktop**

• OS: Linux
• Browser and version: Node.js 20

Additional context

This behavior started occurring after upgrading to v10. No issues before v10.
From the changelog, I think the VM changes broke this.

[80avin]

This is because the same mode only implements a subset of JavaScript.
If you change void 0 to undefined, it appears to work.

We can add support for void also but we should stop at some point accepting that we cannot implement entire javascript in it.
Can you describe your usecase to understand why void 0 must be added ?

ref: demo

[flyerH]

I'm using ​​@stoplight/spectral v5​​, which has built-in jsonpath rules that I can't modify.

I also tested ​​jsonpath-plus v9​​. Even though the docs say eval is safe by default, it still works fine. Maybe v9 has a complete JS VM implementation?

[80avin]

@flyerH VM in v9 had few bugs and was using some keywords from outside the sandbox. That might be causing void to work.

I checked and it is only 2 lines of code to add void operator.
I'll add when back on my machine.