Dependency Graph

Analyze and visualize dependency relationships in your container.

Cycle Detection

Uses Tarjan's Strongly Connected Components algorithm to detect circular dependencies:

const result = container.validate();

if (!result.valid) {
  for (const error of result.errors) {
    console.error(error);
    // "Circular dependency detected: A -> B -> C -> A"
  }
}

Visualizing Dependencies

// Get the dependency graph
const graph = container.getDependencyGraph();

// Detect cycles
const cycles = graph.detectCycles();
if (cycles.length > 0) {
  console.log('Cycles found:', cycles);
}

// Get cycle analysis
const analysis = graph.getCycleAnalysis();
console.log(analysis);
// { cycles: [...], depth: 3, totalNodes: 10, cycleNodes: 3 }

// Find missing dependencies
const missing = graph.getMissingDependencies();
console.log('Missing:', missing);

// Get resolution order (topological sort)
const order = graph.getResolutionOrder();
console.log('Resolution order:', order);

// Visualize as string
const visualization = graph.visualize();
console.log(visualization);
// Dependency Graph:
//   UserService [singleton] -> [UserRepository]
//   UserRepository [singleton] -> [DatabaseConnection]
//   DatabaseConnection [singleton] -> []

Container Statistics

Track resolution performance:

const stats = container.getStatistics();

console.log(stats);
// {
//   resolutions: 1500,  // Total get() calls
//   creates: 50,        // New instance creations
//   cacheHits: 1450,    // Cache hits (singleton reuse)
//   errors: 2           // Resolution errors
// }

Calculating Metrics

const stats = container.getStatistics();

// Cache hit rate
const hitRate = stats.cacheHits / stats.resolutions;
console.log(`Cache hit rate: ${(hitRate * 100).toFixed(1)}%`);

// Error rate
const errorRate = stats.errors / stats.resolutions;
console.log(`Error rate: ${(errorRate * 100).toFixed(2)}%`);

Best Practices

1. Validate before production - Catch dependency issues early with container.validate()
2. Monitor statistics - Track cache hit rates to identify performance issues
3. Visualize complex graphs - Use graph.visualize() for debugging
4. Check resolution order - Ensure dependencies resolve in expected order

Next Steps

• Injection Functions - Modern inject() API
• Testing - Testing dependency graphs
• API Reference - Complete API documentation