Failing to Parse Valid JSON

[jgibson2]

The library fails to parse seemingly-valid JSON

What is the issue you have?

This code snippet:

std::string jsonStr = R"({ "key": [ { "id": "this_is_a_string", "color": { "r": 125, "g": 23, "b": 78 } } ] })";
auto json = nlohmann::json::parse(jsonStr);

Fails with:

libc++abi.dylib: terminating with uncaught exception of type nlohmann::detail::parse_error: [json.exception.parse_error.101] parse error at 62: syntax error - unexpected string literal; expected '}'

What is the expected behavior?

No error to be thrown; the JSON is apparently valid:
https://jsonlint.com/?json={%20%22key%22:%20[%20{%20%22id%22:%20%22this_is_a_string%22,%20%22color%22:%20{%20%22r%22:%20125,%20%22g%22:%2023,%20%22b%22:%2078%20}%20}%20]%20}

And what is the actual behavior instead?

A crash, seemingly when parsing the integers -- it works when the integers are quoted.

Which compiler and operating system are you using?

OSX, with

Apple clang version 11.0.3 (clang-1103.0.32.62)
Target: x86_64-apple-darwin19.5.0
Thread model: posix
InstalledDir: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin

Which version of the library did you use?

• latest release version 3.7.3
• other release - please state the version: ___
• the develop branch

If you experience a compilation error: can you compile and run the unit tests?

• yes
• no - please copy/paste the error message below

[nlohmann]

I cannot reproduce the issue with the same compiler.

Apple clang version 11.0.3 (clang-1103.0.32.62)
Target: x86_64-apple-darwin19.5.0
Thread model: posix
InstalledDir: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin

Full code for reference (using develop branch 29ad217):

#include <iostream>
#include "json.hpp"

using json = nlohmann::json;

int main() {
    std::string jsonStr = R"({ "key": [ { "id": "this_is_a_string", "color": { "r": 125, "g": 23, "b": 78 } } ] })";
    auto j = json::parse(jsonStr);
    std::cout << j << std::endl;
}

Output:

{"key":[{"color":{"b":78,"g":23,"r":125},"id":"this_is_a_string"}]}

Can you please double check your code?

[jgibson2]

I ran that exact code and got the same error... very strange! Let me try with that specific branch.

[nlohmann]

Can you try to execute the unit tests?

[jgibson2]

My "develop" was old. Works as expected with latest version. Thank you :)

[nlohmann]

Thanks for checking back!

[chloro-pn]

I ran that exact code and got the same error... very strange! Let me try with that specific branch.

I get the same error on version 3.7.3 ...
The error occurs occasionally, when I call a lot of json::parse func.

• macOS 10.14.6

[nlohmann]

The library will accept any valid JSON as long as it’s UTF-8 encoded. Can you copy the exact input and the code you use to parse it?

[chloro-pn]

Sorry, I can't provide the specific data, because I chunked a large file and called JSON:: parse to serialize it. I found this error in the log file, and I found that the error is not deterministic, even if the same input data. I will continue to test it with other third-party JSON libraries, and I will reply in time whether there is an error in my program itself or the cause of JSON:: parse.

[nlohmann]

If it’s nondeterministic, maybe you pass an invalid input buffer. Try running it with ASAN.

[chloro-pn]

I will

[chloro-pn]

It's my mistake , I mistakenly used the network library, resulting in a message error.
sorry to bother you.