safesearch: imp tests

CHANGELOG.md

@@ -14,11 +14,11 @@ and this project adheres to
 <!--
 ## [v0.108.0] - TBA
 
-## [v0.107.32] - 2023-06-28 (APPROX.)
+## [v0.107.33] - 2023-06-28 (APPROX.)
 
-See also the [v0.107.32 GitHub milestone][ms-v0.107.32].
+See also the [v0.107.33 GitHub milestone][ms-v0.107.33].
 
-[ms-v0.107.32]: https://github.com/AdguardTeam/AdGuardHome/milestone/68?closed=1
+[ms-v0.107.33]: https://github.com/AdguardTeam/AdGuardHome/milestone/68?closed=1
 
 NOTE: Add new changes BELOW THIS COMMENT.
 -->
@@ -82,7 +82,8 @@ In this release, the schema version has changed from 20 to 21.
 
 ### Fixed
 
-- Safe Search not working with `AAAA` queries for Yandex domains ([#5913]).
+- Safe Search not working with `AAAA` queries for domains that don't have `AAAA`
+  records ([#5913]).
 
 [#951]:  https://github.com/AdguardTeam/AdGuardHome/issues/951
 [#1577]: https://github.com/AdguardTeam/AdGuardHome/issues/1577

internal/filtering/safesearch/safesearch.go

@@ -259,7 +259,7 @@ func (ss *Default) newResult(
 
 	ips, err := ss.resolver.LookupIP(context.Background(), qtypeToProto(qtype), host)
 	if err != nil {
-		return nil, err
+		return nil, fmt.Errorf("resolving cname: %w", err)
 	}
 
 	ss.log(log.DEBUG, "resolved %s", ips)

internal/filtering/safesearch/safesearch_test.go

@@ -1,6 +1,7 @@
 package safesearch_test
 
 import (
+	"context"
 	"net"
 	"testing"
 	"time"
@@ -80,6 +81,14 @@ func TestDefault_CheckHost_yandexAAAA(t *testing.T) {
 	require.NoError(t, err)
 
 	assert.True(t, res.IsFiltered)
+
+	// TODO(a.garipov): Currently, the safe-search filter returns a single rule
+	// with a nil IP address.  This isn't really necessary and should be changed
+	// once the TODO in [safesearch.Default.newResult] is resolved.
+	require.Len(t, res.Rules, 1)
+
+	assert.Nil(t, res.Rules[0].IP)
+	assert.EqualValues(t, filtering.SafeSearchListID, res.Rules[0].FilterListID)
 }
 
 func TestDefault_CheckHost_google(t *testing.T) {
@@ -116,6 +125,56 @@ func TestDefault_CheckHost_google(t *testing.T) {
 	}
 }
 
+// testResolver is a [filtering.Resolver] for tests.
+//
+// TODO(a.garipov): Move to aghtest and use everywhere.
+type testResolver struct {
+	OnLookupIP func(ctx context.Context, network, host string) (ips []net.IP, err error)
+}
+
+// type check
+var _ filtering.Resolver = (*testResolver)(nil)
+
+// LookupIP implements the [filtering.Resolver] interface for *testResolver.
+func (r *testResolver) LookupIP(
+	ctx context.Context,
+	network string,
+	host string,
+) (ips []net.IP, err error) {
+	return r.OnLookupIP(ctx, network, host)
+}
+
+func TestDefault_CheckHost_duckduckgoAAAA(t *testing.T) {
+	conf := testConf
+	conf.CustomResolver = &testResolver{
+		OnLookupIP: func(_ context.Context, network, host string) (ips []net.IP, err error) {
+			assert.Equal(t, "ip6", network)
+			assert.Equal(t, "safe.duckduckgo.com", host)
+
+			return nil, nil
+		},
+	}
+
+	ss, err := safesearch.NewDefault(conf, "", testCacheSize, testCacheTTL)
+	require.NoError(t, err)
+
+	// The DuckDuckGo safe-search addresses are resolved through CNAMEs, but
+	// DuckDuckGo doesn't have a safe-search IPv6 address.  The result should be
+	// the same as the one for Yandex IPv6.  That is, a NODATA response.
+	res, err := ss.CheckHost("www.duckduckgo.com", dns.TypeAAAA)
+	require.NoError(t, err)
+
+	assert.True(t, res.IsFiltered)
+
+	// TODO(a.garipov): Currently, the safe-search filter returns a single rule
+	// with a nil IP address.  This isn't really necessary and should be changed
+	// once the TODO in [safesearch.Default.newResult] is resolved.
+	require.Len(t, res.Rules, 1)
+
+	assert.Nil(t, res.Rules[0].IP)
+	assert.EqualValues(t, filtering.SafeSearchListID, res.Rules[0].FilterListID)
+}
+
 func TestDefault_Update(t *testing.T) {
 	conf := testConf
 	ss, err := safesearch.NewDefault(conf, "", testCacheSize, testCacheTTL)