Make NetworkAddressRulesAdheringDnsResolver testable

By using composition rather than inheritance

Author: Mahoney

src/main/java/com/github/tomakehurst/wiremock/http/NetworkAddressRulesAdheringDnsResolver.java

@@ -20,13 +20,21 @@
 import java.net.InetAddress;
 import java.net.UnknownHostException;
 import java.util.stream.Stream;
+import org.apache.hc.client5.http.DnsResolver;
 import org.apache.hc.client5.http.SystemDefaultDnsResolver;
 
-public class NetworkAddressRulesAdheringDnsResolver extends SystemDefaultDnsResolver {
+public class NetworkAddressRulesAdheringDnsResolver implements DnsResolver {
 
+ private final DnsResolver delegate;
  private final NetworkAddressRules networkAddressRules;
 
  public NetworkAddressRulesAdheringDnsResolver(NetworkAddressRules networkAddressRules) {
+ this(SystemDefaultDnsResolver.INSTANCE, networkAddressRules);
+ }
+
+ public NetworkAddressRulesAdheringDnsResolver(
+ DnsResolver delegate, NetworkAddressRules networkAddressRules) {
+ this.delegate = delegate;
  this.networkAddressRules = networkAddressRules;
  }
 
@@ -36,12 +44,17 @@ public InetAddress[] resolve(String host) throws UnknownHostException {
  throw new ProhibitedNetworkAddressException();
  }
 
- final InetAddress[] resolved = super.resolve(host);
+ final InetAddress[] resolved = delegate.resolve(host);
  if (Stream.of(resolved)
  .anyMatch(address -> !networkAddressRules.isAllowed(address.getHostAddress()))) {
  throw new ProhibitedNetworkAddressException();
  }
 
  return resolved;
  }
+
+ @Override
+ public String resolveCanonicalHostname(String host) throws UnknownHostException {
+ return delegate.resolveCanonicalHostname(host);
+ }
 }