tests: OSS-Fuzz: Add new fuzzer targets otlp json process

[arthurscchan]

This PR creates a new OSS-Fuzz fuzzer targets otlp/json decoding process, together with the fix on OSS-Fuzz (google/oss-fuzz#16089) to prepare the corpora for this new fuzzer.

Summary by CodeRabbit

• Tests
  • Added automated fuzz testing for OTLP/JSON log, metric, and trace decoding.
  • Expanded test target generation to include the new decoder fuzzing coverage.
  • Added safeguards for timeouts, allocation failures, and resource cleanup during testing.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Team

Run ID: 73ff31e8-93e5-4d2b-9fc9-67334047615e

📥 Commits

Reviewing files that changed from the base of the PR and between a31cf11 and c1a17a4.

📒 Files selected for processing (2)

• tests/internal/fuzzers/CMakeLists.txt
• tests/internal/fuzzers/otlp_json_fuzzer.c

Included review availability: Your plan provides up to 8 included reviews per hour; 7 remain after this review.

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📝 Walkthrough

Walkthrough

The pull request adds an OTLP/JSON fuzz target for logs, metrics, and traces. It registers the target in the existing CMake fuzzer list and cleans up decoder resources after each test input.

Changes

OTLP JSON fuzzing

Layer / File(s)	Summary
Fuzzer registration and decoder dispatch tests/internal/fuzzers/otlp_json_fuzzer.c, tests/internal/fuzzers/CMakeLists.txt	The new fuzz target selects a decoder from the first input byte, rejects short inputs, configures allocation failures, frees decoder outputs, and is added to generated test and OSS-Fuzz targets.

Estimated code review effort: 2 (Simple) | ~10 minutes

Merge Risk: ⚪ Minimal · up to c1a17

This change adds isolated OSS-Fuzz coverage for existing OTLP JSON decoders without altering production behavior or deployment paths. No actionable merge-blocking risk remains beyond normal checks and review.

Suggested reviewers: cosmo0920, edsiper

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Docstring Coverage	✅ Passed	Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 1 functions across 1 files. (1 skipped: 1 …
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title identifies the test scope and the addition of OSS-Fuzz targets for OTLP/JSON processing. It is related to the main change, but the wording is grammatically awkward.

Full details: Docstring Coverage

Explanation

Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 1 functions across 1 files. (1 skipped: 1 unsupported.)

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

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[DavidKorczynski]

LGTM from my side! CC @edsiper

[cosmo0920]

❌ Commit c1a17a4a23 failed:
Missing prefix in commit subject: 'OSS-Fuzz: Add new fuzzer targets otlp json process'


Commit prefix validation failed.

We need to follow the guideline of commit message.