Chore: improve error handling and improve tests

pkg/rbl/rbl.go

@@ -1,7 +1,6 @@
 package rbl
 
 import (
-	"fmt"
 	"net"
 	"sync"
 
@@ -70,23 +69,35 @@ func (rbl *Rbl) query(ip string, blacklist string, result *Rblresult) {
 
 	rbl.logger.Debug("About to query RBL", slog.String("rbl", blacklist), slog.String("ip", ip))
 
-	lookup := fmt.Sprintf("%s.%s", ip, blacklist)
+	lookup := ip + "." + blacklist
+	rbl.logger.Debug("Built lookup", slog.String("lookup", lookup))
 
 	res, err := rbl.util.GetARecords(lookup)
-	if len(res) > 0 {
-		result.Listed = true
+	if err != nil {
+		rbl.logger.Error("error occurred fetching A record", slog.String("msg", err.Error()))
+		result.Error = true
+		result.ErrorType = err
+		return
+	}
 
-		txt, _ := net.LookupTXT(lookup)
-		if len(txt) > 0 {
-			result.Text = txt[0]
-		}
+	if len(res) == 0 {
+		// ip is not listed
+		return
 	}
 
+	rbl.logger.Debug("ip is listed", slog.String("ip", ip))
+	result.Listed = true
+
+	// fetch (potential) reason
+	txt, err := net.LookupTXT(lookup)
 	if err != nil {
-		result.Error = true
-		result.ErrorType = err
+		rbl.logger.Error("error occurred fetching TXT record", slog.String("msg", err.Error()))
+		return
 	}
 
+	if len(txt) > 0 {
+		result.Text = txt[0]
+	}
 }
 
 func (rbl *Rbl) lookup(rblList string, targetHost string) []Rblresult {

pkg/rbl/rbl_test.go

@@ -7,18 +7,43 @@ import (
 	"github.com/Luzilla/dnsbl_exporter/pkg/dns"
 	"github.com/Luzilla/dnsbl_exporter/pkg/rbl"
 	x "github.com/miekg/dns"
+	"github.com/stretchr/testify/assert"
 	"golang.org/x/exp/slog"
 )
 
-func TestUpdate(t *testing.T) {
-	logger := slog.New(slog.NewTextHandler(os.Stderr))
+func TestRblSuite(t *testing.T) {
+	t.Run("run=invalid_ip", func(t *testing.T) {
+		logger := slog.New(slog.NewTextHandler(os.Stderr))
 
-	d := dns.New(new(x.Client), "0.0.0.0:53", logger)
+		d := dns.New(new(x.Client), "0.0.0.0:53", logger)
 
-	r := rbl.New(d, logger)
-	r.Update("this.is.not.an.ip", []string{"cbl.abuseat.org"})
+		r := rbl.New(d, logger)
+		r.Update("this.is.not.an.ip", []string{"cbl.abuseat.org"})
 
-	if len(r.Results) > 0 {
-		t.Errorf("Got a result, but shouldn't have: %v", r.Results)
-	}
+		assert.Equal(t, 0, len(r.Results), "Got a result, but shouldn't have: %v", r.Results)
+	})
+
+	t.Run("run=error_result", func(t *testing.T) {
+		logger := slog.New(slog.NewTextHandler(os.Stderr))
+
+		d := dns.New(new(x.Client), "0.0.0.0:53", logger)
+
+		r := rbl.New(d, logger)
+		r.Update("79.214.198.85", []string{"zen.spamhaus.org"})
+
+		assert.Equal(t, 1, len(r.Results))
+
+		result := r.Results[0]
+
+		// assert the right RBL is in there
+		assert.Equal(t, "zen.spamhaus.org", result.Rbl)
+
+		// this is not an error as in transport/dialer
+		assert.False(t, result.Error)
+		assert.NoError(t, result.ErrorType)
+
+		// but the IP is listed
+		assert.True(t, result.Listed)
+		assert.Equal(t, "https://www.spamhaus.org/query/ip/79.214.198.85", result.Text)
+	})
 }