refactor: fully move IDNAResolver to netxlite (#433)

We started doing this in https://github.com/ooni/probe-cli/pull/432.

This work is part of https://github.com/ooni/probe/issues/1733.

internal/engine/netx/resolver/idna.go

@@ -1,34 +1,11 @@
 package resolver
 
 import (
-	"context"
-
-	"golang.org/x/net/idna"
+	"github.com/ooni/probe-cli/v3/internal/netxlite"
 )
 
 // IDNAResolver is to support resolving Internationalized Domain Names.
 // See RFC3492 for more information.
-type IDNAResolver struct {
-	Resolver
-}
+type IDNAResolver = netxlite.ResolverIDNA
 
-// LookupHost implements Resolver.LookupHost
-func (r IDNAResolver) LookupHost(ctx context.Context, hostname string) ([]string, error) {
-	host, err := idna.ToASCII(hostname)
-	if err != nil {
-		return nil, err
-	}
-	return r.Resolver.LookupHost(ctx, host)
-}
-
-// Network implements Resolver.Network.
-func (r IDNAResolver) Network() string {
-	return "idna"
-}
-
-// Address implements Resolver.Address.
-func (r IDNAResolver) Address() string {
-	return ""
-}
-
-var _ Resolver = IDNAResolver{}
+var _ Resolver = &IDNAResolver{}

internal/engine/netx/resolver/idna_test.go

@@ -1,76 +0,0 @@
-package resolver_test
-
-import (
-	"context"
-	"errors"
-	"strings"
-	"testing"
-
-	"github.com/google/go-cmp/cmp"
-	"github.com/ooni/probe-cli/v3/internal/engine/netx/resolver"
-)
-
-var ErrUnexpectedPunycode = errors.New("unexpected punycode value")
-
-type CheckIDNAResolver struct {
-	Addresses []string
-	Error     error
-	Expect    string
-}
-
-func (resolv CheckIDNAResolver) LookupHost(ctx context.Context, hostname string) ([]string, error) {
-	if resolv.Error != nil {
-		return nil, resolv.Error
-	}
-	if hostname != resolv.Expect {
-		return nil, ErrUnexpectedPunycode
-	}
-	return resolv.Addresses, nil
-}
-
-func (r CheckIDNAResolver) Network() string {
-	return "checkidna"
-}
-
-func (r CheckIDNAResolver) Address() string {
-	return ""
-}
-
-func TestIDNAResolverSuccess(t *testing.T) {
-	expectedIPs := []string{"77.88.55.66"}
-	resolv := resolver.IDNAResolver{Resolver: CheckIDNAResolver{
-		Addresses: expectedIPs,
-		Expect:    "xn--d1acpjx3f.xn--p1ai",
-	}}
-	addrs, err := resolv.LookupHost(context.Background(), "яндекс.рф")
-	if err != nil {
-		t.Fatal(err)
-	}
-	if diff := cmp.Diff(expectedIPs, addrs); diff != "" {
-		t.Fatal(diff)
-	}
-}
-
-func TestIDNAResolverFailure(t *testing.T) {
-	resolv := resolver.IDNAResolver{Resolver: CheckIDNAResolver{
-		Error: errors.New("we should not arrive here"),
-	}}
-	// See https://www.farsightsecurity.com/blog/txt-record/punycode-20180711/
-	addrs, err := resolv.LookupHost(context.Background(), "xn--0000h")
-	if err == nil || !strings.HasPrefix(err.Error(), "idna: invalid label") {
-		t.Fatal("not the error we expected")
-	}
-	if addrs != nil {
-		t.Fatal("expected no response here")
-	}
-}
-
-func TestIDNAResolverTransportOK(t *testing.T) {
-	resolv := resolver.IDNAResolver{Resolver: CheckIDNAResolver{}}
-	if resolv.Network() != "idna" {
-		t.Fatal("invalid network")
-	}
-	if resolv.Address() != "" {
-		t.Fatal("invalid address")
-	}
-}

internal/engine/netx/resolver/integration_test.go

@@ -44,8 +44,8 @@ func testresolverquickidna(t *testing.T, reso resolver.Resolver) {
 	if testing.Short() {
 		t.Skip("skip test in short mode")
 	}
-	reso = resolver.IDNAResolver{
-		&netxlite.ResolverLogger{Logger: log.Log, Resolver: reso},
+	reso = &resolver.IDNAResolver{
+		Resolver: &netxlite.ResolverLogger{Logger: log.Log, Resolver: reso},
 	}
 	addrs, err := reso.LookupHost(context.Background(), "яндекс.рф")
 	if err != nil {