Issue

Fixes #2983: Some tests always pass due to wrong assertion

GitHub Issue: #2983

Root Cause Analysis

All 11 serialization round-trip tests used self-referential assertions (assertThat(result).isEqualTo(result)) instead of comparing the deserialized result against the original input. This made the tests tautological — they always passed regardless of whether toJson()/fromJson() worked correctly.

Changes

Changed all 11 test assertions from assertThat(result).isEqualTo(result) to assertThat(result.toJson().toString()).isEqualTo(json), which validates that JSON data survives a full round-trip through fromJson()/toJson().

The JSON string comparison approach was chosen over object equality (isEqualTo(event)) because:

• Some generated model classes (e.g., SpanEvent.Span) are not data class and lack equals() implementations
• JSON type coercion (Long → Double) causes false equality failures even for data classes

Files Changed

Test Coverage

• Tests fixed: 11 (across 4 modules: core, rum, logs, trace)
• Local verification: core (PASS), logs (PASS), trace (PASS)
• Note: RUM module has a pre-existing compilation error (RumVitalAppLaunchEvent redeclaration) on develop, unrelated to this change

Investigation Log

Issue Analysis

The issue reporter identified that multiple test files contained assertThat(result).isEqualTo(result) which always passes. This was confirmed across 11 files in 4 modules (2 more than originally reported).

Reproduction

All 11 affected files follow the same pattern: forge a random event, serialize to JSON, deserialize, and compare. The self-referential assertion never catches serialization bugs.

Fix Approach

1. First attempted assertThat(result).isEqualTo(event) — this revealed real serialization differences (non-data-class types, JSON type coercion)
2. Switched to JSON string comparison which correctly validates round-trip fidelity without depending on object equals()