JSON Path Assertion: Assert key exists in object

[Bert]

How can I verify that a JSON object contains a key?

In the following JSON object the age is missing for the second person, Kevin:

[

{

"name":"John",

"age":30

},

{

"name":"Kevin"

}

]

If I query the JSON Path

$[*].age

and check expected value for

\d+

then then Kevin's object gets silently ignored.

1. I know Jayway's JsonPath, which afaik the JSON Path Assertion plugin is using, has an option (DEFAULT_PATH_LEAF_TO_NULL) to show missing leaves as null. For this case I have already a query to recognize objects with null values. But I don't know how

    to activate this option in the plugin.

2. Is there another way to check for missing keys? A query or setting in the plugin itself?