[duplicate-code] Duplicate Code Analysis Report

[github-actions]

Analysis of commit ac8733a — "Refactor SendRequestWithServerID to use a single inbound response logging path"

Summary

Analysis of the codebase following the recent SendRequestWithServerID refactor (which resolved the duplication that motivated it) reveals 3 remaining significant duplication patterns across internal/guard/wasm.go, internal/server/guard_init.go, and internal/server/tool_registry.go.

Detected Patterns

1. Marshal-for-debug-logging block — Severity: Medium — See [duplicate-code] Duplicate Code Pattern: Marshal-for-debug-logging block in guard/wasm.go and server/guard_init.go #4076
   Identical 5-line marshal + conditional log block repeated 3× across two files.

2. Sys tool handler structural duplication — Severity: Medium — See [duplicate-code] Duplicate Code Pattern: Sys tool handler call-and-log skeleton in tool_registry.go #4077
   sysInitHandler and sysListHandler in registerSysTools() copy the same call → error-handle → marshal → log → return skeleton. Adding a third sys tool requires another copy-paste.

3. Missing result sanitization in sysListHandler — Severity: High — See [duplicate-code] Duplicate Code Pattern: Missing result sanitization in sysListHandler (copy-paste divergence) #4078
   Direct consequence of Pattern 2: sysListHandler omits sanitize.SanitizeString when logging the JSON result, diverging from sysInitHandler and the backend tool handler and creating a potential secret-leak risk in log output.

Overall Impact

• Total Duplicated Lines: ~35 lines across 3 patterns
• Affected Files: internal/guard/wasm.go, internal/server/guard_init.go, internal/server/tool_registry.go
• Maintainability Risk: Medium — patterns will silently diverge as sys tools are added
• Refactoring Priority: Pattern 3 (sanitization gap) should be fixed immediately; Patterns 1 & 2 are medium-priority cleanup

Next Steps

1. Fix the missing sanitization in sysListHandler (Pattern 3) — low-risk, one-line change
2. Extract a logMarshaledForDebug helper to consolidate Pattern 1
3. Introduce a shared helper for the sys-tool call-and-log skeleton (Pattern 2)

Analysis Metadata

• Analyzed Files: internal/guard/wasm.go, internal/server/guard_init.go, internal/server/tool_registry.go (and broad survey of non-test Go sources)
• Detection Method: Static code inspection — pattern search + manual comparison
• Commit: ac8733aff67ad6e95c4fef045c8cac6fbcdb9b65
• Analysis Date: 2026-04-18