zsvo/test/test_singleton_fix.go

package main

import (
	"fmt"
	"os"
	"time"

	"zsvo/pkg/resolver"
)

func main() {
	fmt.Println("🧪 Testing Singleton Resolver Fix")
	fmt.Println("=================================")

	cacheDir := "/tmp/zsvo_test_singleton"
	mirror := "https://deb.debian.org/debian"
	suite := "stable"
	component := "main"

	// Remove any existing cache
	os.RemoveAll(cacheDir)

	// Test 1: Multiple GetGlobalResolver calls should only parse once
	fmt.Printf("\n📦 Test 1: Multiple GetGlobalResolver calls...\n")
	
	start := time.Now()
	
	// First call - should parse Sources.xz
	fmt.Printf("Call 1: ")
	r1, err := resolver.GetGlobalResolver(cacheDir, mirror, suite, component)
	if err != nil {
		fmt.Printf("❌ Error: %v\n", err)
		return
	}
	duration1 := time.Since(start)
	fmt.Printf("✅ %v\n", duration1)

	// Second call - should be instant
	start = time.Now()
	fmt.Printf("Call 2: ")
	r2, err := resolver.GetGlobalResolver(cacheDir, mirror, suite, component)
	if err != nil {
		fmt.Printf("❌ Error: %v\n", err)
		return
	}
	duration2 := time.Since(start)
	fmt.Printf("✅ %v\n", duration2)

	// Third call - should also be instant
	start = time.Now()
	fmt.Printf("Call 3: ")
	r3, err := resolver.GetGlobalResolver(cacheDir, mirror, suite, component)
	if err != nil {
		fmt.Printf("❌ Error: %v\n", err)
		return
	}
	duration3 := time.Since(start)
	fmt.Printf("✅ %v\n", duration3)

	// Verify same instance
	if r1 == r2 && r2 == r3 {
		fmt.Printf("✅ Same resolver instance (singleton working)\n")
	} else {
		fmt.Printf("❌ Different instances (singleton failed)\n")
	}

	// Test 2: Multiple dependency resolutions should not re-parse
	fmt.Printf("\n📦 Test 2: Multiple dependency resolutions...\n")
	
	totalStart := time.Now()
	resolutions := 0
	
	for i := 0; i < 5; i++ {
		start = time.Now()
		
		// Try to resolve a package (this will trigger dependency resolution)
		graph, err := r1.ResolveDependencies("cmake")
		if err != nil {
			fmt.Printf("  Resolution %d: ❌ %v\n", i+1, err)
		} else {
			duration := time.Since(start)
			nodeCount, maxLevel := graph.GetStats()
			fmt.Printf("  Resolution %d: ✅ %v (%d packages, %d levels)\n", 
				i+1, duration, nodeCount, maxLevel)
		}
		resolutions++
	}
	
	totalDuration := time.Since(totalStart)
	avgDuration := totalDuration / time.Duration(resolutions)
	
	fmt.Printf("📊 Total time for %d resolutions: %v\n", resolutions, totalDuration)
	fmt.Printf("📈 Average per resolution: %v\n", avgDuration)

	// Results
	fmt.Printf("\n🎯 Test Results:\n")
	fmt.Printf("• First resolver init: %v\n", duration1)
	fmt.Printf("• Second resolver init: %v\n", duration2)
	fmt.Printf("• Third resolver init: %v\n", duration3)
	fmt.Printf("• Average resolution time: %v\n", avgDuration)
	
	// Check if singleton is working correctly
	if duration2 < time.Millisecond && duration3 < time.Millisecond {
		fmt.Printf("✅ SUCCESS: Singleton pattern working (subsequent calls <1ms)\n")
	} else {
		fmt.Printf("❌ FAILED: Singleton pattern broken (subsequent calls >1ms)\n")
		fmt.Printf("   Expected: <1ms, Got: %v, %v\n", duration2, duration3)
	}

	// Check for performance regression
	if avgDuration < 10*time.Millisecond {
		fmt.Printf("✅ SUCCESS: No repeated parsing (avg resolution <10ms)\n")
	} else {
		fmt.Printf("❌ FAILED: Repeated parsing detected (avg resolution >10ms)\n")
	}

	fmt.Printf("\n📋 Expected behavior:\n")
	fmt.Printf("• LoadIndex() should execute only once inside sync.Once\n")
	fmt.Printf("• Subsequent GetGlobalResolver() calls should be <1ms\n")
	fmt.Printf("• Dependency resolutions should not trigger re-parsing\n")
}