refactor(netx): use netxlite for AddressResolver (#500)

Part of https://github.com/ooni/probe/issues/1591.

internal/engine/netx/netx.go

@@ -118,7 +118,9 @@ func NewResolver(config Config) Resolver {
 		config.BaseResolver = &netxlite.ResolverSystem{}
 	}
 	var r Resolver = config.BaseResolver
-	r = resolver.AddressResolver{Resolver: r}
+	r = &resolver.AddressResolver{
+		Resolver: netxlite.NewResolverLegacyAdapter(r),
+	}
 	if config.CacheResolutions {
 		r = &resolver.CacheResolver{Resolver: r}
 	}

internal/engine/netx/netx_test.go

@@ -35,11 +35,15 @@ func TestNewResolverVanilla(t *testing.T) {
 	if !ok {
 		t.Fatal("not the resolver we expected")
 	}
-	ar, ok := ewr.Resolver.(resolver.AddressResolver)
+	ar, ok := ewr.Resolver.(*resolver.AddressResolver)
 	if !ok {
 		t.Fatal("not the resolver we expected")
 	}
-	_, ok = ar.Resolver.(*netxlite.ResolverSystem)
+	arw, ok := ar.Resolver.(*netxlite.ResolverLegacyAdapter)
+	if !ok {
+		t.Fatal("not the resolver we expected")
+	}
+	_, ok = arw.ResolverLegacy.(*netxlite.ResolverSystem)
 	if !ok {
 		t.Fatal("not the resolver we expected")
 	}
@@ -63,11 +67,15 @@ func TestNewResolverSpecificResolver(t *testing.T) {
 	if !ok {
 		t.Fatal("not the resolver we expected")
 	}
-	ar, ok := ewr.Resolver.(resolver.AddressResolver)
+	ar, ok := ewr.Resolver.(*resolver.AddressResolver)
 	if !ok {
 		t.Fatal("not the resolver we expected")
 	}
-	_, ok = ar.Resolver.(resolver.BogonResolver)
+	arw, ok := ar.Resolver.(*netxlite.ResolverLegacyAdapter)
+	if !ok {
+		t.Fatal("not the resolver we expected")
+	}
+	_, ok = arw.ResolverLegacy.(resolver.BogonResolver)
 	if !ok {
 		t.Fatal("not the resolver we expected")
 	}
@@ -93,11 +101,15 @@ func TestNewResolverWithBogonFilter(t *testing.T) {
 	if !ok {
 		t.Fatal("not the resolver we expected")
 	}
-	ar, ok := br.Resolver.(resolver.AddressResolver)
+	ar, ok := br.Resolver.(*resolver.AddressResolver)
 	if !ok {
 		t.Fatal("not the resolver we expected")
 	}
-	_, ok = ar.Resolver.(*netxlite.ResolverSystem)
+	arw, ok := ar.Resolver.(*netxlite.ResolverLegacyAdapter)
+	if !ok {
+		t.Fatal("not the resolver we expected")
+	}
+	_, ok = arw.ResolverLegacy.(*netxlite.ResolverSystem)
 	if !ok {
 		t.Fatal("not the resolver we expected")
 	}
@@ -138,11 +150,15 @@ func TestNewResolverWithLogging(t *testing.T) {
 	if !ok {
 		t.Fatalf("not the resolver we expected %T", rla.ResolverLegacy)
 	}
-	ar, ok := ewr.Resolver.(resolver.AddressResolver)
+	ar, ok := ewr.Resolver.(*resolver.AddressResolver)
 	if !ok {
 		t.Fatal("not the resolver we expected")
 	}
-	_, ok = ar.Resolver.(*netxlite.ResolverSystem)
+	arw, ok := ar.Resolver.(*netxlite.ResolverLegacyAdapter)
+	if !ok {
+		t.Fatal("not the resolver we expected")
+	}
+	_, ok = arw.ResolverLegacy.(*netxlite.ResolverSystem)
 	if !ok {
 		t.Fatal("not the resolver we expected")
 	}
@@ -172,11 +188,15 @@ func TestNewResolverWithSaver(t *testing.T) {
 	if !ok {
 		t.Fatal("not the resolver we expected")
 	}
-	ar, ok := ewr.Resolver.(resolver.AddressResolver)
+	ar, ok := ewr.Resolver.(*resolver.AddressResolver)
 	if !ok {
 		t.Fatal("not the resolver we expected")
 	}
-	_, ok = ar.Resolver.(*netxlite.ResolverSystem)
+	arw, ok := ar.Resolver.(*netxlite.ResolverLegacyAdapter)
+	if !ok {
+		t.Fatal("not the resolver we expected")
+	}
+	_, ok = arw.ResolverLegacy.(*netxlite.ResolverSystem)
 	if !ok {
 		t.Fatal("not the resolver we expected")
 	}
@@ -205,11 +225,15 @@ func TestNewResolverWithReadWriteCache(t *testing.T) {
 	if cr.ReadOnly != false {
 		t.Fatal("expected readwrite cache here")
 	}
-	ar, ok := cr.Resolver.(resolver.AddressResolver)
+	ar, ok := cr.Resolver.(*resolver.AddressResolver)
 	if !ok {
 		t.Fatal("not the resolver we expected")
 	}
-	_, ok = ar.Resolver.(*netxlite.ResolverSystem)
+	arw, ok := ar.Resolver.(*netxlite.ResolverLegacyAdapter)
+	if !ok {
+		t.Fatal("not the resolver we expected")
+	}
+	_, ok = arw.ResolverLegacy.(*netxlite.ResolverSystem)
 	if !ok {
 		t.Fatal("not the resolver we expected")
 	}
@@ -243,11 +267,15 @@ func TestNewResolverWithPrefilledReadonlyCache(t *testing.T) {
 	if cr.Get("dns.google.com")[0] != "8.8.8.8" {
 		t.Fatal("cache not correctly prefilled")
 	}
-	ar, ok := cr.Resolver.(resolver.AddressResolver)
+	ar, ok := cr.Resolver.(*resolver.AddressResolver)
 	if !ok {
 		t.Fatal("not the resolver we expected")
 	}
-	_, ok = ar.Resolver.(*netxlite.ResolverSystem)
+	arw, ok := ar.Resolver.(*netxlite.ResolverLegacyAdapter)
+	if !ok {
+		t.Fatal("not the resolver we expected")
+	}
+	_, ok = arw.ResolverLegacy.(*netxlite.ResolverSystem)
 	if !ok {
 		t.Fatal("not the resolver we expected")
 	}

internal/engine/netx/resolver/address.go

@@ -1,22 +1,9 @@
 package resolver
 
 import (
-	"context"
+	"github.com/ooni/probe-cli/v3/internal/netxlite"
-	"net"
 )
 
 // AddressResolver is a resolver that knows how to correctly
 // resolve IP addresses to themselves.
-type AddressResolver struct {
+type AddressResolver = netxlite.AddressResolver
-	Resolver
-}
-
-// LookupHost implements Resolver.LookupHost
-func (r AddressResolver) LookupHost(ctx context.Context, hostname string) ([]string, error) {
-	if net.ParseIP(hostname) != nil {
-		return []string{hostname}, nil
-	}
-	return r.Resolver.LookupHost(ctx, hostname)
-}
-
-var _ Resolver = AddressResolver{}

internal/engine/netx/resolver/address_test.go

@@ -1,36 +0,0 @@
-package resolver_test
-
-import (
-	"context"
-	"errors"
-	"testing"
-
-	"github.com/ooni/probe-cli/v3/internal/engine/netx/resolver"
-)
-
-func TestAddressSuccess(t *testing.T) {
-	r := resolver.AddressResolver{}
-	addrs, err := r.LookupHost(context.Background(), "8.8.8.8")
-	if err != nil {
-		t.Fatal(err)
-	}
-	if len(addrs) != 1 || addrs[0] != "8.8.8.8" {
-		t.Fatal("not the result we expected")
-	}
-}
-
-func TestAddressFailure(t *testing.T) {
-	expected := errors.New("mocked error")
-	r := resolver.AddressResolver{
-		Resolver: resolver.FakeResolver{
-			Err: expected,
-		},
-	}
-	addrs, err := r.LookupHost(context.Background(), "dns.google.com")
-	if !errors.Is(err, expected) {
-		t.Fatal("not the error we expected")
-	}
-	if addrs != nil {
-		t.Fatal("expected nil addrs")
-	}
-}

internal/netxlite/legacy.go

@@ -33,6 +33,7 @@ type (
 	DialerSystem              = dialerSystem
 	TLSDialerLegacy           = tlsDialer
 	UserAgentTransport        = httpUserAgentTransport
+	AddressResolver           = resolverShortCircuitIPAddr
 )
 
 // ResolverLegacy performs domain name resolutions.