| name | architecture-review |
| description | Analyze JavaScript/TypeScript module architecture using jscan - class coupling (CBO), instability metrics, and circular dependency detection. Use when user asks about architecture, module structure, coupling, or circular dependencies. |
JavaScript/TypeScript Architecture Review with jscan
Run the jscan CLI to understand module structure and coupling. No install needed: npx jscan@latest <command>.
Commands
| User Request | Command |
|---|
| "Check class coupling" | npx jscan@latest analyze --text --select cbo <path> |
| "Find circular dependencies" | npx jscan@latest analyze --text --select deps <path> |
| "Map the module dependencies" | npx jscan@latest deps <path> |
| "Which modules are risky to change?" | npx jscan@latest deps --format json <path> |
| "Draw the dependency graph" | npx jscan@latest deps --format dot <path> | dot -Tsvg -o deps.svg |
jscan deps flags: --format text|json|dot, --include-external (include npm packages), --no-cycles (skip cycle detection), --min-coupling <n> (filter low-coupling modules in DOT output), --max-depth <n>.
Text output shows per-class CBO and cycle membership, but only aggregate coupling stats for modules. Per-module Martin metrics live in deps --format json: analysis.ModuleMetrics (Ca/Ce, instability, abstractness, distance, risk level per module) and analysis.CouplingAnalysis (explicit ZoneOfPain / MainSequence module lists).
Interpreting Coupling Results
- High CBO classes depend on many others; changes ripple widely. Suggest interface extraction or dependency inversion.
- Martin metrics per module (from the JSON output above): instability I = Ce / (Ca + Ce) and distance from the main sequence. Modules in the Zone of Pain (stable but concrete) are risky to change; name them explicitly.
- Dependency cycles are the highest-priority architectural issue; name the modules in each cycle and the weakest edge to break.
Always tie findings back to concrete modules and suggest a specific structural change.
