mev-beta/pkg/security/rate_limiter_test.go

package security

import (
	"context"
	"testing"
	"time"
)

func TestEnhancedRateLimiter(t *testing.T) {

	config := &RateLimiterConfig{
		IPRequestsPerSecond:     5,
		IPBurstSize:             10,
		GlobalRequestsPerSecond: 10000, // Set high global limit
		GlobalBurstSize:         20000, // Set high global burst
		UserRequestsPerSecond:   1000,  // Set high user limit
		UserBurstSize:           2000,  // Set high user burst
		SlidingWindowEnabled:    false, // Disabled for testing basic burst logic
		SlidingWindowSize:       time.Minute,
		SlidingWindowPrecision:  time.Second,
		AdaptiveEnabled:         false, // Disabled for testing basic burst logic
		AdaptiveAdjustInterval:  100 * time.Millisecond,
		SystemLoadThreshold:     80.0,
		BypassDetectionEnabled:  true,
		BypassThreshold:         3,
		CleanupInterval:         time.Minute,
		BucketTTL:               time.Hour,
	}

	rl := NewEnhancedRateLimiter(config)
	defer rl.Stop()

	ctx := context.Background()
	headers := make(map[string]string)

	// Test basic rate limiting
	for i := 0; i < 3; i++ {
		result := rl.CheckRateLimitEnhanced(ctx, "127.0.0.1", "test-user", "TestAgent", "test", headers)
		if !result.Allowed {
			t.Errorf("Request %d should be allowed, but got: %s - %s", i+1, result.ReasonCode, result.Message)
		}
	}

	// Test burst capacity (should allow up to burst size)
	// We already made 3 requests, so we can make 7 more before hitting the limit
	for i := 0; i < 7; i++ {
		result := rl.CheckRateLimitEnhanced(ctx, "127.0.0.1", "test-user", "TestAgent", "test", headers)
		if !result.Allowed {
			t.Errorf("Request %d should be allowed within burst, but got: %s - %s", i+4, result.ReasonCode, result.Message)
		}
	}

	// Now we should exceed the burst limit and be rate limited
	for i := 0; i < 5; i++ {
		result := rl.CheckRateLimitEnhanced(ctx, "127.0.0.1", "test-user", "TestAgent", "test", headers)
		if result.Allowed {
			t.Errorf("Request %d should be rate limited (exceeded burst)", i+11)
		}
	}
}

func TestSlidingWindow(t *testing.T) {
	window := NewSlidingWindow(5, time.Minute, time.Second)

	// Test within limit
	for i := 0; i < 5; i++ {
		if !window.IsAllowed() {
			t.Errorf("Request %d should be allowed", i+1)
		}
	}

	// Test exceeding limit
	if window.IsAllowed() {
		t.Error("Request should be denied after exceeding limit")
	}
}

func TestBypassDetection(t *testing.T) {
	detector := NewBypassDetector(3, time.Hour, time.Minute)
	headers := make(map[string]string)

	// Test normal behavior
	result := detector.DetectBypass("127.0.0.1", "TestAgent", headers, false)
	if result.BypassDetected {
		t.Error("Normal behavior should not trigger bypass detection")
	}

	// Test bypass pattern (multiple rate limit hits)
	for i := 0; i < 25; i++ { // Increased to trigger MEDIUM severity
		result = detector.DetectBypass("127.0.0.1", "TestAgent", headers, true)
	}

	if !result.BypassDetected {
		t.Error("Multiple rate limit hits should trigger bypass detection")
	}

	if result.Severity != "MEDIUM" && result.Severity != "HIGH" {
		t.Errorf("Expected MEDIUM or HIGH severity, got %s", result.Severity)
	}
}

func TestSystemLoadMonitor(t *testing.T) {
	monitor := NewSystemLoadMonitor(100 * time.Millisecond)
	defer monitor.Stop()

	// Allow some time for monitoring to start
	time.Sleep(200 * time.Millisecond)

	cpu, memory, load, goroutines := monitor.GetCurrentLoad()

	if cpu < 0 || cpu > 100 {
		t.Errorf("CPU usage should be between 0-100, got %f", cpu)
	}

	if memory < 0 || memory > 100 {
		t.Errorf("Memory usage should be between 0-100, got %f", memory)
	}

	if load < 0 {
		t.Errorf("Load average should be positive, got %f", load)
	}

	if goroutines <= 0 {
		t.Errorf("Goroutine count should be positive, got %d", goroutines)
	}
}

func TestEnhancedMetrics(t *testing.T) {
	config := &RateLimiterConfig{
		IPRequestsPerSecond:    10,
		SlidingWindowEnabled:   true,
		AdaptiveEnabled:        true,
		AdaptiveAdjustInterval: 100 * time.Millisecond,
		BypassDetectionEnabled: true,
		CleanupInterval:        time.Second,
		BypassThreshold:        5,
		BypassDetectionWindow:  time.Minute,
		BypassAlertCooldown:    time.Minute,
	}

	rl := NewEnhancedRateLimiter(config)
	defer rl.Stop()

	metrics := rl.GetEnhancedMetrics()

	// Check that all expected metrics are present
	expectedKeys := []string{
		"sliding_window_enabled",
		"adaptive_enabled",
		"bypass_detection_enabled",
		"system_cpu_usage",
		"system_memory_usage",
		"system_load_average",
		"system_goroutines",
	}

	for _, key := range expectedKeys {
		if _, exists := metrics[key]; !exists {
			t.Errorf("Expected metric %s not found", key)
		}
	}

	// Verify boolean flags
	if metrics["sliding_window_enabled"] != true {
		t.Error("sliding_window_enabled should be true")
	}

	if metrics["adaptive_enabled"] != true {
		t.Error("adaptive_enabled should be true")
	}

	if metrics["bypass_detection_enabled"] != true {
		t.Error("bypass_detection_enabled should be true")
	}
}