chore: fix enr flaky test with local dns resolver (#935)

waku/v2/dnsdisc/enr_test.go

@@ -2,17 +2,64 @@ package dnsdisc
 
 import (
 	"context"
+	"errors"
 	"testing"
 
+	"github.com/ethereum/go-ethereum/common/hexutil"
+	"github.com/ethereum/go-ethereum/crypto"
+	"github.com/ethereum/go-ethereum/p2p/dnsdisc"
+	"github.com/ethereum/go-ethereum/p2p/enode"
 	"github.com/stretchr/testify/require"
 )
 
-// TestRetrieveNodes uses a live connection, so it could be
-// flaky, it should though pay for itself and should be fairly stable
-func TestRetrieveNodes(t *testing.T) {
-	url := "enrtree://AO47IDOLBKH72HIZZOXQP6NMRESAN7CHYWIBNXDXWRJRZWLODKII6@test.wakuv2.nodes.status.im"
+type mapResolver map[string]string
 
-	nodes, err := RetrieveNodes(context.Background(), url)
-	require.NoError(t, err)
-	require.NotEmpty(t, nodes)
+func (mr mapResolver) LookupTXT(ctx context.Context, name string) ([]string, error) {
+	if record, ok := mr[name]; ok {
+		return []string{record}, nil
+	}
+	return nil, errors.New("not found")
+}
+
+var signingKeyForTesting, _ = crypto.ToECDSA(hexutil.MustDecode("0xdc599867fc513f8f5e2c2c9c489cde5e71362d1d9ec6e693e0de063236ed1240"))
+
+func makeTestTree(domain string, nodes []*enode.Node, links []string) (*dnsdisc.Tree, string) {
+	tree, err := dnsdisc.MakeTree(1, nodes, links)
+	if err != nil {
+		panic(err)
+	}
+	url, err := tree.Sign(signingKeyForTesting, domain)
+	if err != nil {
+		panic(err)
+	}
+	return tree, url
+}
+
+func parseNodes(rec []string) []*enode.Node {
+	var ns []*enode.Node
+	for _, r := range rec {
+		var n enode.Node
+		if err := n.UnmarshalText([]byte(r)); err != nil {
+			panic(err)
+		}
+		ns = append(ns, &n)
+	}
+	return ns
+}
+
+func TestRetrieveNodes(t *testing.T) {
+	nodes := []string{
+		"enr:-Ji4QAa0VR5P27XvDEZzuFf1lnO6OGzm4hPhVtVYPFqlB-9vZnZtc-lzmEqY4stHFTIazRnSzwhlYne0UMIAmFMZ8o2GAYwawiLNgmlkgnY0gmlwhMCoAWSJc2VjcDI1NmsxoQLtnTLtFmyU8AFqO8Jw4X9zBfB6fWJxsMk9YpyrPeNPkoN0Y3CCw6qDdWRwgsm6hXdha3UyAQ",
+		"enr:-Ji4QPr-1R0uv6QSYSwtsjG-ksFvW6zEWRlIzkJGmr9SAPjcWmU7xM-3njzP0ByLhP3xNBBxeF_V5baEjITy6RuPKtuGAYwawtZPgmlkgnY0gmlwhMCoAWSJc2VjcDI1NmsxoQJyiENqCiVwzkluXBexKPA4eeLZU_Q2v0f0gRen_xoQaoN0Y3CCxJ6DdWRwgt4uhXdha3UyAQ",
+	}
+	tree, url := makeTestTree("n", parseNodes(nodes), nil)
+	resolver := mapResolver(tree.ToTXT("n"))
+
+	var opts []DNSDiscoveryOption
+	opts = append(opts, WithResolver(resolver))
+
+	discoveredNodes, err := RetrieveNodes(context.Background(), url, opts...)
+
+	require.NoError(t, err)
+	require.Equal(t, len(discoveredNodes), 2)
 }