Support parsing partial json in appsec

[cataphract]

Description

Backport partial json parsing from API10 branch.

Reviewer checklist

• Test coverage seems ok.
• Appropriate labels assigned.

[datadog-datadog-prod-us1]

⚠️ Tests

✨ Fix all issues with BitsAI or with Cursor

⚠️ Warnings

🧪 1028 Tests failed

testSearchPhpBinaries from integration.DDTrace\Tests\Integration\PHPInstallerTest (Datadog) (Fix with Cursor)

DDTrace\Tests\Integration\PHPInstallerTest::testSearchPhpBinaries
Test code or tested code printed unexpected output: Searching for available php binaries, this operation might take a while.

testSimplePushAndProcess from laravel-58-test.DDTrace\Tests\Integrations\Laravel\V5_8\QueueTest (Datadog) (Fix with Cursor)

Risky Test
phpvfscomposer://tests/vendor/phpunit/phpunit/phpunit:97

testSimplePushAndProcess from laravel-8x-test.DDTrace\Tests\Integrations\Laravel\V8_x\QueueTest (Datadog) (Fix with Cursor)

DDTrace\Tests\Integrations\Laravel\V8_x\QueueTest::testSimplePushAndProcess
Test code or tested code printed unexpected output: spanLinksTraceId: 69a1d3410000000083f09d845cebae69
tid: 69a1d34100000000
hexProcessTraceId: 83f09d845cebae69
hexProcessSpanId: 343091081193bd97
processTraceId: 9507272005199310441
processSpanId: 3760665152695025047

View all

ℹ️ Info

❄️ No new flaky tests detected

_{This comment will be updated automatically if new data arrives.
🔗 Commit SHA: 1622f8d | Docs | Datadog PR Page | Was this helpful? React with 👍/👎 or give us feedback!}

[codecov-commenter]

Codecov Report

❌ Patch coverage is 74.50980% with 65 lines in your changes missing coverage. Please review.
✅ Project coverage is 62.39%. Comparing base (6733f8f) to head (1622f8d).

Files with missing lines	Patch %	Lines
appsec/src/extension/json_truncated_parser.cpp	73.72%	47 Missing and 15 partials ⚠️
appsec/src/extension/entity_body.c	88.23%	1 Missing and 1 partial ⚠️
appsec/src/extension/logging.h	50.00%	0 Missing and 1 partial ⚠️

❌ Your patch status has failed because the patch coverage (74.50%) is below the target coverage (90.00%). You can increase the patch coverage or adjust the target coverage.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #3680      +/-   ##
==========================================
+ Coverage   62.20%   62.39%   +0.19%     
==========================================
  Files         141      142       +1     
  Lines       13352    13586     +234     
  Branches     1746     1775      +29     
==========================================
+ Hits         8305     8477     +172     
- Misses       4256     4304      +48     
- Partials      791      805      +14     

Files with missing lines	Coverage Δ
appsec/src/extension/php_compat.h	100.00% <ø> (ø)
appsec/src/extension/logging.h	96.29% <50.00%> (ø)
appsec/src/extension/entity_body.c	80.39% <88.23%> (+1.68%)	⬆️
appsec/src/extension/json_truncated_parser.cpp	73.72% <73.72%> (ø)

... and 2 files with indirect coverage changes

---

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[pr-commenter]

Benchmarks [ appsec ]

Benchmark execution time: 2026-02-27 17:54:23

Comparing candidate commit 1622f8d in PR branch glopes/partial-json with baseline commit 6733f8f in branch master.

Found 0 performance improvements and 0 performance regressions! Performance is the same for 12 metrics, 0 unstable metrics.

[estringana]

Why have you decided to go for a CPP implementation on the exension?

[cataphract]

It was dictated by the choice of library (rapidjson). The C libraries with SAX-like, event-driven API have not seen updates in more than a decade.

[estringana]

Why is this changed?

[cataphract]

3df4e17f08#diff-d7c6e792306074c39c93c98658584807ea65a8c68bbce5c3d353e3afc0a87e55L1-L19 changed the location where version.hpp was generated (no more on the source tree), so this ignore is not needed anymore

[estringana]

Just a few questions but nothing big