JsonPathParser seems to wrongly parse unescaped reference-token if its starts with a number

[laurent-gougeon]

Hello,

First of all, I want to thank you for sharing this fork !

In the context of evaluating this fork as a replacement of unmaintained original https://github.com/java-json-tools/json-patch, I think I found an issue in the JsonPathParser

Version used: 2.0.1

simple test code :

    String inputToPatch = "{\"5gStringToMove\":\"exists\"}";

    JsonPatchOperation operation = new MoveOperation("/5gStringToMove", "/5gStringMoved");

    var patch = new JsonPatch(List.of(operation));
    JsonNode objToBePatched = JsonLoader.fromString(inputToPatch);
    JsonNode result = null;
    try
    {
        result = patch.apply(objToBePatched);
    } catch (JsonPatchException e)
    {
        TRACER.fatal(e.getMessage(), e);
        Assertions.fail(e);
    }

The attribute name and JsonPointer towards the attribute is valid as per RFC 6901
Such attribute names are quite frequent in 3GPP standards for example.

But the lib fails in converting the JsonPointer to Json Path :

com.gravity9.jsonpatch.JsonPatchException: Filter: [5]['gStringToMove'] can only be applied to arrays. Current context is: {"5gStringToMove":"exists"}
at com.gravity9.jsonpatch.JsonPatchOperation.apply(JsonPatchOperation.java:124) ~[json-patch-path-2.0.1.jar:?]
at com.gravity9.jsonpatch.JsonPatch.apply(JsonPatch.java:144) ~[json-patch-path-2.0.1.jar:?]
at com.my.example.test.testMoveElementSimple(Test.java:368) ~[test-classes/:?]

The parser considered the number as an array index while it's not even a number, then it split to next char and consider another attribue name.

The issue is more or less here:
https://github.com/gravity9-tech/json-patch-path/blob/master/src/main/java/com/gravity9/jsonpatch/JsonPathParser.java#L7
and here
https://github.com/gravity9-tech/json-patch-path/blob/master/src/main/java/com/gravity9/jsonpatch/JsonPathParser.java#L27

Not sure how to fix this, though...

Original https://github.com/java-json-tools/json-patch was able to patch the same data.

Rgds
Laurent

[MateuszGravity9]

Hello,

@laurent-gougeon Thank you for raising the issue, we are looking into resolving it. I will keep you posted.

[laurent-gougeon]

@MateuszGravity9 thanks for that fix. It seems to work with the provided testcase.

However I feel like there is still some remaining issue, but I'm not 100% sure of the validity of the following case:

let's pick the data:

{ "mymap" : { "1" : "valueFor1", "a": valueFora" } }

and the JsonPointer:

/mymap/1
/mymap/a

both could select the proper entry with Json-patch 1.13

/mymap/1 fails with json-patch-path 2.0.2

as it will blindly consider the 1 as indicating an array element.

The OpenApi spec just states that map key should be string. which is the case there. "1" is a string representing a number in the json document.

I couldn't find clue in https://datatracker.ietf.org/doc/html/rfc6901 or https://datatracker.ietf.org/doc/rfc9535/ of how to map that properly in a JsonPath ...

Maybe you have ideas ?