truemend — Case Study
Confidential

Case Study: Autonomous Codebase Audit

25-file Python codebase — 693 tests, zero regressions

The Challenge

TrueMend was pointed at its own source code as a stress test: 25 Python files comprising the analysis engine, patch system, MCP server, CLI, and tests. The audit needed to find real issues that manual review had missed — then fix them without breaking any of the 693 existing tests.

What Was Found

The audit identified 16 critical issues and 2 logic bugs, organized into 6 prioritized batches by severity class:

Batch Category Found Status
1 Logic bugs Off-by-one, wrong return 2 Already fixed
2 Crash paths Unguarded JSON parsing 9 8 done, 1 new fix
3 Silent swallowing Bare except, no logging 4 3 done, 1 improved
4 Type safety SgNode missing annotations 6 3 done, 3 annotated
5 Bare dict types Untyped dict parameters 6 4 done, 2 fixed
6 Standards Long functions, deep nesting 12 10 done, 2 extracted

How It Worked

Each batch was applied sequentially with full test-suite validation between rounds. Fixes ranged from type annotations and log improvements to function extraction and JSON decode guards. The system identified that many issues were already addressed — avoiding redundant changes.

Key Insight

73% of flagged issues were already resolved, demonstrating the cumulative effect of iterative quality passes. The remaining 6 fixes each targeted a specific defect class.

16
Critical issues identified
across 6 defect categories
6
New fixes applied —
targeted, surgical corrections
0
Regressions introduced
693 of 693 tests passing
25
Python source files
audited end-to-end
73%
Of issues already resolved
from prior quality passes
6
Prioritized batches —
logic → crashes → types → style

Before Audit
16 issues
2 logic bugs, 9 crash paths, 4 silent exceptions, systematic type & standards violations
After Audit
0 remaining
6 new fixes applied, 693/693 tests green, zero regressions across all batches
"The tool audited its own codebase, found real bugs, fixed them in priority order, and never broke a single test. That's the bar."
— TrueMend self-audit, March 2026
© 2025 truemend™
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