Parsing sparql-10-2-2b.sparql produces results that do not match with sparql-10-2-2b.json

[yamalight]

So, parser for some reason omits UNDEF fields for VALUES.

Expected output:

"type": "values",
"values": [
  {
    "?title": "\"SPARQL Tutorial\"",
    "?book": "{undefined}"
  },
  {
    "?title": "{undefined}",
    "?book": "http://example.org/book/book2"
  }
]

Actual output:

"type": "values",
"values": [
  {
    "?title": "\"SPARQL Tutorial\"",
  },
  {
    "?book": "http://example.org/book/book2"
  }
]

[RubenVerborgh]

Thanks for reporting. The code behaves fine though. The expected output is actually:

"values": [
  {
    "?title": "\"SPARQL Tutorial\"",
    "?book": undefined
  },
  {
    "?title": undefined,
    "?book": "http://example.org/book/book2"
  }
]

But since undefined is not valid JSON (as you can see above), for the tests, we identify the value undefined by "{undefined}". This is restored back in the test code.