[duplicate-code] Duplicate Code Pattern: DIFC Component Fields Duplicated in Server and Proxy Structs

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Part of duplicate code analysis: #4711

Summary

Both UnifiedServer (internal/server/unified.go) and Server (internal/proxy/proxy.go) independently declare an identical set of DIFC component fields. This structural duplication means any addition of a new DIFC component requires updates in two separate structs.

Duplication Details

Pattern: Duplicated DIFC component fields in two structs

• Severity: Medium

• Occurrences: 2

• Locations:

  • internal/server/unified.go — UnifiedServer struct (lines ~100–104)
  • internal/proxy/proxy.go — Server struct (lines ~41–44)

• Code Sample (server/unified.go):

  guardRegistry *guard.Registry
  agentRegistry *difc.AgentRegistry
  capabilities  *difc.Capabilities
  evaluator     *difc.Evaluator

• Code Sample (proxy/proxy.go):

  guard         guard.Guard
  evaluator     *difc.Evaluator
  agentRegistry *difc.AgentRegistry
  capabilities  *difc.Capabilities

The initialization of these fields also uses the same difc.NewComponents(...) pattern in both packages (server via difc.NewComponents, proxy via explicit field assignment).

Impact Analysis

• Maintainability: Adding a new DIFC component (e.g. a new registry type) requires updating two structs.
• Bug Risk: Low, but the divergence (guard.Registry in server vs single guard.Guard in proxy) indicates the two have already begun to diverge.
• Code Bloat: Minor (~8 lines), but sets a precedent for further divergence.

Refactoring Recommendations

1. Introduce a DIFCComponents struct in internal/difc/ (already partially exists as difc.NewComponents return):

   type Components struct {
       AgentRegistry *AgentRegistry
       Capabilities  *Capabilities
       Evaluator     *Evaluator
   }

   Both UnifiedServer and proxy Server embed *difc.Components instead of individual fields.
   • Estimated effort: 1–2 hours
   • Benefits: single definition, new components automatically propagate

Implementation Checklist

• Review duplication findings
• Check if difc.NewComponents already returns a composable struct (it does — leverage it)
• Embed *difc.Components in both UnifiedServer and proxy Server
• Update all field references to use the embedded struct
• Verify no functionality broken

Parent Issue

See parent analysis report: #4711
Related to #4711

Generated by Duplicate Code Detector · ● 1M · ◷

• expires on May 5, 2026, 6:23 AM UTC