[duplicate-code] Duplicate Code Pattern: Repeated logger-initialisation error blocks in cmd/root.go and cmd/proxy.go

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Part of duplicate code analysis: #3309

Summary

internal/cmd/root.go initialises five loggers using an identical 3-line pattern (if err := logger.InitXxx(...); err != nil { log.Printf("Warning: ...") }). The same structure (abbreviated to two loggers) is also repeated in internal/cmd/proxy.go. This is a classic copy-paste initialisation block that could be extracted into a single helper function.

Duplication Details

Pattern: Repeated logger-initialisation error blocks

• Severity: Medium
• Occurrences: 5 in root.go + 2 in proxy.go = 7 blocks (≈21 lines)
• Locations:
  • internal/cmd/root.go (lines 129–151)
  • internal/cmd/proxy.go (lines 144–149)
• Code Sample (root.go lines 129–151):

if err := logger.InitFileLogger(logDir, "mcp-gateway.log"); err != nil {
    log.Printf("Warning: Failed to initialize file logger: %v", err)
}
if err := logger.InitServerFileLogger(logDir); err != nil {
    log.Printf("Warning: Failed to initialize server file logger: %v", err)
}
if err := logger.InitMarkdownLogger(logDir, "gateway.md"); err != nil {
    log.Printf("Warning: Failed to initialize markdown logger: %v", err)
}
if err := logger.InitJSONLLogger(logDir, "rpc-messages.jsonl"); err != nil {
    log.Printf("Warning: Failed to initialize JSONL logger: %v", err)
}
if err := logger.InitToolsLogger(logDir, "tools.json"); err != nil {
    log.Printf("Warning: Failed to initialize tools logger: %v", err)
}

• Code Sample (proxy.go lines 144–149):

if err := logger.InitFileLogger(proxyLogDir, "proxy.log"); err != nil {
    log.Printf("Warning: Failed to initialize file logger: %v", err)
}
if err := logger.InitJSONLLogger(proxyLogDir, "rpc-messages.jsonl"); err != nil {
    log.Printf("Warning: Failed to initialize JSONL logger: %v", err)
}

Impact Analysis

• Maintainability: Adding a new logger type requires editing every callsite; currently two files.
• Bug Risk: If the warning format or error handling changes, all sites must be updated.
• Code Bloat: 21 lines reducible to ~2 calls.

Refactoring Recommendations

1. Add an InitGatewayLoggers(logDir string) helper in internal/logger/ that initialises the standard set of gateway loggers and returns a combined error or logs warnings internally:

   // internal/logger/init.go
   func InitGatewayLoggers(logDir string) {
       initWithWarning(InitFileLogger(logDir, "mcp-gateway.log"), "file logger")
       initWithWarning(InitServerFileLogger(logDir), "server file logger")
       initWithWarning(InitMarkdownLogger(logDir, "gateway.md"), "markdown logger")
       initWithWarning(InitJSONLLogger(logDir, "rpc-messages.jsonl"), "JSONL logger")
       initWithWarning(InitToolsLogger(logDir, "tools.json"), "tools logger")
   }
   
   func initWithWarning(err error, name string) {
       if err != nil {
           log.Printf("Warning: Failed to initialize %s: %v", name, err)
       }
   }

2. root.go becomes: logger.InitGatewayLoggers(logDir)

3. proxy.go can call a lighter InitProxyLoggers(logDir string) variant.

   Estimated effort: ~1 hour. Very low regression risk.

Implementation Checklist

• Create internal/logger/init.go with InitGatewayLoggers and InitProxyLoggers
• Update internal/cmd/root.go (lines 129–151) to call InitGatewayLoggers
• Update internal/cmd/proxy.go (lines 144–149) to call InitProxyLoggers
• Verify all loggers still initialise correctly via make test-integration
• Run make agent-finished

Parent Issue

See parent analysis report: #3309
Related to #3309

Generated by Duplicate Code Detector · ● 2.2M · ◷

• expires on Apr 14, 2026, 6:05 AM UTC