nameserver.go: refactor requiresRRUpdate and add basic tests

nameserver_test.go

@@ -0,0 +1,68 @@
+package main
+
+import (
+	"net"
+	"testing"
+
+	"github.com/foxcpp/go-mockdns"
+)
+
+func TestRequiresRRUpdate(t *testing.T) {
+	tests := []struct {
+		name   string
+		record string
+		addr   net.IP
+		expRes bool
+	}{
+		{
+			"nonexistent record",
+			"invalid.example.org",
+			net.ParseIP("1.1.1.1"),
+			true,
+		},
+		{
+			"ipv4 update required",
+			"ipv4.example.org",
+			net.ParseIP("1.1.1.1"),
+			true,
+		},
+		{
+			"ipv4 up to date",
+			"ipv4.example.org",
+			net.ParseIP("2.2.2.2"),
+			false,
+		},
+		{
+			"ipv6 up to date",
+			"ipv6.example.org",
+			net.ParseIP("1:1:1:1:1:1:1:1"),
+			true,
+		},
+		{
+			"ipv6 up to date",
+			"ipv6.example.org",
+			net.ParseIP("2:2:2:2:2:2:2:2"),
+			false,
+		},
+	}
+
+	// setup mock resolver
+	resolver := mockdns.Resolver{
+		Zones: map[string]mockdns.Zone{
+			"ipv4.example.org.": {
+				A: []string{"2.2.2.2"},
+			},
+			"ipv6.example.org.": {
+				AAAA: []string{"2:2:2:2:2:2:2:2"},
+			},
+		},
+	}
+
+	for _, tc := range tests {
+		res := requiresRRUpdate(tc.record, tc.addr, &resolver)
+
+		if tc.expRes != res {
+			t.Errorf("%s: has=%v, wanted=%v", tc.name, res, tc.expRes)
+		}
+	}
+}