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package resolver
import (
"sync"
"testing"
)
func TestNewDNSResolver(t *testing.T) {
resolver := NewDNSResolver()
if resolver == nil {
t.Fatal("NewDNSResolver returned nil")
}
if resolver.cache == nil {
t.Fatal("cache map not initialized")
}
if len(resolver.cache) != 0 {
t.Errorf("expected empty cache, got size %d", len(resolver.cache))
}
}
func TestIsIPAddress(t *testing.T) {
tests := []struct {
input string
expected bool
}{
{"192.168.1.1", true},
{"10.0.0.1", true},
{"255.255.255.255", true},
{"2001:db8::1", true},
{"::1", true},
{"not-an-ip", false},
{"", false},
{"256.1.1.1", false},
{"192.168.1", false},
{"server.example.com", false},
}
for _, tt := range tests {
result := isIPAddress(tt.input)
if result != tt.expected {
t.Errorf("isIPAddress(%q) = %v, want %v", tt.input, result, tt.expected)
}
}
}
func TestResolveIP_InvalidIP(t *testing.T) {
resolver := NewDNSResolver()
invalidInputs := []string{
"not-an-ip",
"server.example.com",
"",
"invalid",
}
for _, input := range invalidInputs {
hostname, ok := resolver.ResolveIP(input)
if ok {
t.Errorf("ResolveIP(%q) returned ok=true for invalid IP", input)
}
if hostname != "" {
t.Errorf("ResolveIP(%q) returned hostname=%q for invalid IP", input, hostname)
}
}
}
func TestResolveIP_Localhost(t *testing.T) {
resolver := NewDNSResolver()
// Test localhost resolution (should work on most systems)
hostname, ok := resolver.ResolveIP("127.0.0.1")
// We expect either success with "localhost" or failure (depending on system DNS config)
// Just verify the function doesn't panic and caches the result
if ok && hostname == "" {
t.Error("ResolveIP returned ok=true but empty hostname")
}
// Verify caching - second call should hit cache
initialCacheSize := resolver.GetCacheSize()
if initialCacheSize != 1 {
t.Errorf("expected cache size 1 after first lookup, got %d", initialCacheSize)
}
// Second lookup should use cache
hostname2, ok2 := resolver.ResolveIP("127.0.0.1")
if hostname2 != hostname || ok2 != ok {
t.Error("second lookup returned different result (cache not working)")
}
// Cache size should still be 1
if resolver.GetCacheSize() != 1 {
t.Errorf("cache size changed on second lookup")
}
}
func TestResolveIP_CachingFailedLookup(t *testing.T) {
resolver := NewDNSResolver()
// Use a private IP that likely won't resolve
nonExistentIP := "192.168.255.254"
// First lookup
hostname1, ok1 := resolver.ResolveIP(nonExistentIP)
// Verify it's cached (even if it failed)
if resolver.GetCacheSize() != 1 {
t.Errorf("expected cache size 1 after first lookup, got %d", resolver.GetCacheSize())
}
// Second lookup should return same result from cache
hostname2, ok2 := resolver.ResolveIP(nonExistentIP)
if hostname1 != hostname2 {
t.Errorf("hostname changed between lookups: %q vs %q", hostname1, hostname2)
}
if ok1 != ok2 {
t.Errorf("ok changed between lookups: %v vs %v", ok1, ok2)
}
// Cache size should still be 1
if resolver.GetCacheSize() != 1 {
t.Errorf("cache size should remain 1, got %d", resolver.GetCacheSize())
}
}
func TestResolveIP_MultipleIPs(t *testing.T) {
resolver := NewDNSResolver()
ips := []string{
"127.0.0.1",
"192.168.1.1",
"10.0.0.1",
}
// Resolve all IPs
for _, ip := range ips {
resolver.ResolveIP(ip)
}
// Verify all are cached
if resolver.GetCacheSize() != len(ips) {
t.Errorf("expected cache size %d, got %d", len(ips), resolver.GetCacheSize())
}
// Resolve again to verify cache hits
for _, ip := range ips {
resolver.ResolveIP(ip)
}
// Cache size should not change
if resolver.GetCacheSize() != len(ips) {
t.Errorf("cache size changed on second pass")
}
}
func TestResolveIP_Concurrent(t *testing.T) {
resolver := NewDNSResolver()
// Test concurrent access to ensure thread safety
var wg sync.WaitGroup
numGoroutines := 50
for i := 0; i < numGoroutines; i++ {
wg.Add(1)
go func(id int) {
defer wg.Done()
// Each goroutine resolves a few IPs
ips := []string{
"127.0.0.1",
"192.168.1.1",
"10.0.0.1",
}
for _, ip := range ips {
resolver.ResolveIP(ip)
}
}(i)
}
wg.Wait()
// Despite concurrent access, cache should only have unique IPs
expectedSize := 3
if resolver.GetCacheSize() != expectedSize {
t.Errorf("expected cache size %d after concurrent access, got %d",
expectedSize, resolver.GetCacheSize())
}
}
func TestResolveIP_IPv6(t *testing.T) {
resolver := NewDNSResolver()
// Test IPv6 localhost
hostname, ok := resolver.ResolveIP("::1")
// Should be cached regardless of success
if resolver.GetCacheSize() != 1 {
t.Errorf("expected cache size 1, got %d", resolver.GetCacheSize())
}
// If successful, hostname should not be empty
if ok && hostname == "" {
t.Error("ResolveIP returned ok=true but empty hostname for IPv6")
}
}
func TestGetCacheSize(t *testing.T) {
resolver := NewDNSResolver()
if resolver.GetCacheSize() != 0 {
t.Errorf("expected initial cache size 0, got %d", resolver.GetCacheSize())
}
// Add entries
resolver.ResolveIP("127.0.0.1")
if resolver.GetCacheSize() != 1 {
t.Errorf("expected cache size 1 after first entry, got %d", resolver.GetCacheSize())
}
resolver.ResolveIP("192.168.1.1")
if resolver.GetCacheSize() != 2 {
t.Errorf("expected cache size 2 after second entry, got %d", resolver.GetCacheSize())
}
// Resolving same IP shouldn't increase size
resolver.ResolveIP("127.0.0.1")
if resolver.GetCacheSize() != 2 {
t.Errorf("expected cache size to remain 2, got %d", resolver.GetCacheSize())
}
}
|
