| name | catalog-reducer-filter-development |
| description | Guidance for adding or modifying product selection filters in the current catalog reducer under tmp/, while preserving ordering semantics, statistics, and XML compatibility. Use when implementing or reviewing changes in tmp/lib/filters, tmp/lib/filterManager.js, tmp/lib/parser.js, or config-driven selection behavior. |
| license | MIT |
| compatibility | VS Code agent mode, GitHub Copilot coding agent, Node.js CommonJS projects |
Catalog Reducer Filter Development
Use this skill to make safe, minimal changes to filter behavior in the current reducer implementation under tmp/.
When to Use This Skill
- Adding a new filter in
tmp/lib/filters/
- Modifying selection logic for existing filters
- Updating filter order or parser registration flow
- Extending statistics or config-driven behavior tied to filtering
- Planning how existing filter behavior should be preserved during plugin migration
- Not for: Pure documentation updates or output-only formatting tweaks
Prerequisites
- Understand the current CLI flow in
tmp/reducer.js
- Understand parsing and filter registration in
tmp/lib/parser.js
- Read base behavior in
tmp/lib/filters/filter.js
Core Workflow
- Confirm desired behavior from config and filter order.
- Change the smallest possible filter surface.
- Preserve deduplication and selection caps.
- Keep master and variant expansion logic consistent.
- Run a representative reduction command and verify all expected XML outputs are written.
Ordering Constraints
Current execution order in the reducer test pipeline is:
PreferredMasterProductsFilterMasterFilterPreferredProductsFilterAttributeFilterFillerProductsFilter
Treat this as behavior-defining order. Reorder only when explicitly requested and document why.
Implementation Guardrails
- Reuse existing filter contracts and statistics tracking where possible.
- Keep selected product IDs as the canonical dedupe source across filter passes.
- If changing config behavior, add safe defaults in
tmp/config/default.json.
- Preserve compatibility with SFCC-style catalog, inventory, and pricebook XML structures.
- If the change is part of plugin migration work, keep the behavior grounded in the current reducer until the new contract is intentionally changed.
Quick Reference
| File | Responsibility |
|---|
tmp/reducer.js | CLI argument parsing and startup |
tmp/lib/parser.js | Orchestrates parsing and output generation |
tmp/lib/filterManager.js | Runs filters and tracks selection state |
tmp/lib/filters/*.js | Concrete selection strategies |
tmp/config/*.json | Selection targets and constraints |
Verification Checklist
- Filter stops when intended
- No duplicate products are selected across filter passes
- Master expansion still tracks variants and variation groups correctly
- Catalog, inventory, and pricebook outputs are generated as expected
- Behavior changes are explained in terms of selection semantics
References
