[duplicate-code] Duplicate Code Pattern: SecrecyLabel/IntegrityLabel Structural Duplication

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🔍 Duplicate Code Pattern: SecrecyLabel/IntegrityLabel Structural Duplication

Part of duplicate code analysis: #5517

Summary

internal/difc/labels.go defines two wrapper types — SecrecyLabel and IntegrityLabel — that are structurally identical except for their type names and the boolean flag passed to checkFlowHelper. The six method pairs below are near-identical.

Duplication Details

Pattern: Parallel type hierarchies with identical boilerplate

• Severity: Medium
• Occurrences: 6 pairs of mirrored methods (~34 duplicated lines)
• Locations: internal/difc/labels.go

SecrecyLabel	IntegrityLabel	Lines
NewSecrecyLabel()	NewIntegrityLabel()	181–183, 313–315
NewSecrecyLabelWithTags()	NewIntegrityLabelWithTags()	186–188, 318–320
(l *SecrecyLabel) getLabel()	(l *IntegrityLabel) getLabel()	191–196, 323–328
(l *SecrecyLabel) CanFlowTo()	(l *IntegrityLabel) CanFlowTo()	201–204, 334–337
(l *SecrecyLabel) CheckFlow()	(l *IntegrityLabel) CheckFlow()	296–298, 340–342
(l *SecrecyLabel) Clone()	(l *IntegrityLabel) Clone()	301–303, 345–347

Code Sample (getLabel — identical implementation in both types):

// SecrecyLabel version (lines 191–196)
func (l *SecrecyLabel) getLabel() *Label {
    if l == nil {
        return nil
    }
    return l.Label
}

// IntegrityLabel version (lines 323–328) — word-for-word identical
func (l *IntegrityLabel) getLabel() *Label {
    if l == nil {
        return nil
    }
    return l.Label
}

Code Sample (Clone — identical implementation in both types):

// SecrecyLabel version (line 301–303)
func (l *SecrecyLabel) Clone() *SecrecyLabel {
    return &SecrecyLabel{Label: cloneLabelOrNew(l.getLabel())}
}

// IntegrityLabel version (lines 345–347)
func (l *IntegrityLabel) Clone() *IntegrityLabel {
    return &IntegrityLabel{Label: cloneLabelOrNew(l.getLabel())}
}

Impact Analysis

• Maintainability: If a new method (e.g., IsEmpty(), String()) is added to one type, it must be manually added to the other or the two types silently diverge.
• Bug Risk: Low today; medium over time as types evolve independently.
• Code Bloat: ~34 extra lines of boilerplate that serve no unique purpose.

Refactoring Recommendations

1. Go Generics (preferred) — Introduce a generic FlowLabel[T] that wraps *Label and carries a checkSubset bool constant at construction time:

   type FlowLabel[T any] struct {
       Label      *Label
       checkSubset bool
   }
   func (l *FlowLabel[T]) CanFlowTo(target *FlowLabel[T]) bool { ... }
   func (l *FlowLabel[T]) Clone() *FlowLabel[T]               { ... }

   Keep thin named type aliases (type SecrecyLabel = FlowLabel[secrecyKind]) for backwards-compatible public API.

2. Composition via embedded struct (simpler alternative) — Embed a shared baseLabel struct in both types and promote the shared methods. Only CanFlowTo/CheckFlow need per-type overrides.

Implementation Checklist

• Review duplication findings
• Decide between generics and composition approach
• Implement refactoring
• Ensure SecrecyLabel/IntegrityLabel public API remains unchanged
• Verify all existing tests pass

Parent Issue

See parent analysis report: #5517
Related to #5517

Generated by Duplicate Code Detector · ● 1.2M · ◷

• expires on May 19, 2026, 3:40 AM UTC