No exception thrown when using an empty json path on calling json_query

[Flow86]

After upgrading from v0.144.0 I encountered an issue when using an empty json path:
With the old version I got an exception thrown "The provided JSONPath is incorrect.".
With the new version, an empty result is returned.

I thought that an empty json path is invalid?

What is the expected behavior?
Exception thrown when using an empty json path (= invalid) on calling json_query

What is the actual behavior?
An empty result is returned.

Enumerate the steps to reproduce the bug
query jsoncons::jsonpath::json_query with an empty path

Include a small, self-contained example if possible

auto json = jsoncons::json::parse(R"({ "a": 1 })");
auto path = "";
auto result = jsoncons::jsonpath::json_query(json, path);
// expected: exception jsoncons::jsonpath::jsonpath_error thrown
// actual: result.empty() == true

What compiler, architecture, and operating system?

• Compiler: MSVC / clang
• Architecture: x64
• Operating system: Windows, Linux (Debian)

What jsoncons library version?

• Latest release v0.160.0

[Flow86]

Ah, It seems this behavior was changed in #270 by purpose

[danielaparker]

Reopening. It was changed, but I'm no longer sure that was right. We're currently working on a major rewrite of the jsonpath extension, and may reconsider that. Generally, we want syntax errors in the path expression to be reported, and execution errors when applying the path to a particular JSON instance to result in an empty array.

Comparing with other implementations:

Empty

[danielaparker]

As of the next release, 0.161.0, an empty JSONPath string will be regarded as a syntax error and an error will be raised, see #306.