Fix JSON formatting in crash.json template

[Kartikayy007]

Title: Invalid JSON Syntax in crash.json Template

Description

The source_code field in crash.json template has invalid syntax due to missing quotes and improper escaping, causing parse errors in generated reports.

Current implementation:

"source_code": {{ get_benchmark_final_target_code(sample.id) | replace('\\n', '\\\\n')}}

Reference

This issue was identified in #891 "Anomalies in recent experiments"

Incorrect JSON content

https://llm-exp.oss-fuzz.com/Result-reports/scheduled/2025-03-15-weekly-all-1/benchmark/output-cppcheck-_zn8cppcheck5checkerk15filewithdetails/crash.json

        "coverage_report": "#",
        "stacktrace": "/stacktrace",
        "target_binary": "/target_binary",
        "reproducer": "/artifacts",
        "run_log": "run.log",
        "source_code": ,

[Kartikayy007]

Hey @DonggeLiu I mentioned in #891 that it could be due to missing quotes "source_code": {{ get_benchmark_final_target_code(sample.id) | replace('\\n', '\\\\n')}} but I think there could be other possibilities too like the get_benchmark_final_target_code() function may be failing silently, can we can add fallbacks in the template?

[DonggeLiu]

but I think there could be other possibilities too

Yep definitely. I am not sure if this happens on all cases or certain corner cases.
For example, it could happen due to code errors or flaky experiment failures.
Unfortunately, I do not have the time to investigate now.

Please feel free to add this to the GSoC idea list.

can we can add fallbacks in the template?

It could be more time-efficient to add more logs into the related experiment code to identify the root cause so that we can fix it.
We can also save those data at runtime in the result dir.
The current template is fine, at least we can tell something wrong happened.

BTW, in that issue I was mainly referring to other fields (e.g, reproducer), but thanks for noticing the error in source_code.

[DonggeLiu]

BTW, would you mind if I delete your previous comment, given it has been moved here?
Thanks!

[Kartikayy007]

BTW, would you mind if I delete your previous comment, given it has been moved here?
Thanks!

Sure we can, let me just delete my self

[Ekam219]

@DonggeLiu @Kartikayy007

While this PR effectively resolves the immediate JSON syntax errors - great work adding quotes and escaping critical characters! To make this solution fully robust and maintainable, I recommend these complementary improvements:

. Comprehensive Escaping

Current Approach:

"source_code": "{{ ... | replace('"','\\"') | replace('\n','\\n') }}"  

Suggested Enhancement:

"source_code": {{ get_benchmark_final_target_code(...) | tojson }}  

Why Better:

• Automatically handles all special characters (\, ", \n, unicode)
• Reduces template complexity (no manual replacements)
• Built-in null safety → renders null instead of ""

I'm happy to help out

[Kartikayy007]

@DonggeLiu @Kartikayy007

While this PR effectively resolves the immediate JSON syntax errors - great work adding quotes and escaping critical characters! To make this solution fully robust and maintainable, I recommend these complementary improvements:

. Comprehensive Escaping

Current Approach:

"source_code": "{{ ... | replace('"','\"') | replace('\n','\n') }}"
Suggested Enhancement:

"source_code": {{ get_benchmark_final_target_code(...) | tojson }}
Why Better:

• Automatically handles all special characters (\, ", \n, unicode)
• Reduces template complexity (no manual replacements)
• Built-in null safety → renders null instead of ""

I'm happy to help out

yup that sounds good to use tojson its Less prone to escaping-related bugs