DRY Refactoring Guide

Help users eliminate code duplication by extracting shared logic into reusable modules.

When This Applies

• User mentions "duplicates", "DRY", "repeated code", "copy-paste"

• /bluera-base:dry scan

  found duplicates that need refactoring
• Code review identified similar patterns across files

When Duplication is Acceptable

Not all duplication is bad. Keep duplicates when:

1. Test code: Explicit test cases can repeat for clarity
2. Generated code: Don't DRY generated files
3. Incidental similarity: Coincidentally similar code that may diverge
4. Coupling cost: Extraction would create tight coupling between unrelated modules

Refactoring Workflow

1. Analyze the Duplicates

# Run scan if not already done
/bluera-base:dry scan

# Review the report
/bluera-base:dry report

2. Categorize Each Duplicate

Category	Action
Exact copy	Extract immediately
Near-duplicate	Parameterize differences, then extract
Structural	Consider codegen/templates
Coincidental	Leave as-is, document why

3. Choose Extraction Target

Scope	Target
Same file	Local function/method
Same module/package	Shared utility file
Across modules	New shared module
Across repos	Shared library/package

4. Execute Extraction

1. Create the shared abstraction
2. Move one instance, verify tests pass
3. Replace remaining instances
4. Update imports/exports
5. Run tests after each replacement

5. Validate

• All tests pass
• No circular dependencies introduced
• Public API unchanged (if applicable)
• Code is actually simpler (not over-abstracted)

Anti-patterns to Avoid

1. Wrong abstraction: Forcing unrelated code together
2. Over-parameterization: Too many config options
3. Premature extraction: Extracting before patterns stabilize
4. Leaky abstraction: Exposing implementation details

Language-Specific Patterns

See

skills/dry-refactor/references/patterns.md

for detailed examples:

Language	Primary Pattern
JS/TS	Module export, barrel index
Python	Module with init.py
Rust	Submodule with pub use
Go	Same-package separate file

Report Integration

When

/bluera-base:dry scan

identifies duplicates:

1. Review the report at

   .bluera/bluera-base/state/dry-report.md

2. Start with highest-impact duplicates (most tokens/instances)
3. Use suggested extraction targets from the report
4. Re-run

   /bluera-base:dry scan

   after refactoring to verify reduction