JMESPath: valid query hits JSONCONS_ASSERT on stack size

[Lazrius]

I have a what I believe is a valid query, as it works on all the online playgrounds I have tried, and also works with the Python implementation of JMESPath. The query is as follows:

to_array("gw:GWallInfo"."gw:DocumentStatistics"."gw:ContentGroups"."gw:ContentGroup" || "gw:DocumentStatistics"."gw:ContentGroups"."gw:ContentGroup")[]."gw:IssueItems"."gw:IssueItem" | []

I would expect this query to work fine but it instead results in an assertions being triggered and preventing normal usage.

Minimal Code Example:

#include "jsoncons/basic_json.hpp"
#include "jsoncons_ext/jmespath/jmespath.hpp"

int main(int argc, char* argv[])
{
    auto json = jsoncons::json::parse("{}");
    auto result = jsoncons::jmespath::search(json,
                                             "to_array(\"gw:GWallInfo\".\"gw:DocumentStatistics\".\"gw:ContentGroups\".\"gw:ContentGroup\" || "
                                             "\"gw:DocumentStatistics\".\"gw:ContentGroups\".\"gw:ContentGroup\")[].\"gw:IssueItems\".\"gw:IssueItem\" | []");
    return 0;
}

The exception is thrown on line 2642 of jmespath.hpp, which for me reads: JSONCONS_ASSERT(stack.size() >= 2); - it is inside the token_kind::binary_operator section.

What compiler, architecture, and operating system?

• Compiler: MSVC Visual Studio 2022
• Architecture (e.g. x86, x64) x64
• Operating system: Windows 11

What jsoncons library version?

• Latest release 1.3.0
• Other release ______
• master

If relevant, using the VCPKG version.

[danielaparker]

You're right, there's an issue with parsing a function that is passed a binary expression, e.g. A || B. You can get around that for now by enclosing the entire argument in parentheses,

int main()
{
    std::string query = R"(
to_array(("gw:GWallInfo"."gw:DocumentStatistics"."gw:ContentGroups"."gw:ContentGroup" || 
    "gw:DocumentStatistics"."gw:ContentGroups"."gw:ContentGroup"))
)";
    auto expr = jsoncons::jmespath::make_expression<jsoncons::json>(query);
    jsoncons::json j;
    j["gw:DocumentStatistics"]["gw:ContentGroups"]["gw:ContentGroup"] = 9;
    auto result = expr.evaluate(j);
    std::cout << result << "\n";

Output:

[9]

We should have a fix on master soon.

[danielaparker]

Fixed on master