Add basic NSD format with tests

2 files changed, 135 insertions, 0 deletions

diff --git a/nsd.go b/nsd.go
new file mode 100644
index 0000000..88aeee1
--- /dev/null
+++ b/nsd.go
@@ -0,0 +1,47 @@
+package dyndns
+
+import (
+	"bufio"
+	"bytes"
+	"fmt"
+	"regexp"
+	"strconv"
+	"text/template"
+)
+
+type nsdFormat struct {
+}
+
+func (f nsdFormat) Write(hosts []Host) ([]byte, error) {
+	var out bytes.Buffer
+	t := template.Must(template.New("zone").Parse(nsdZone))
+	err := t.Execute(&out, hosts)
+	return out.Bytes(), err
+}
+
+func (f nsdFormat) Read(b []byte) (out []Host, err error) {
+	re := regexp.MustCompile(nsdRE)
+
+	scanner := bufio.NewScanner(bytes.NewReader(b))
+	for scanner.Scan() {
+		r := re.FindStringSubmatch(scanner.Text())
+		if len(r) != 5 {
+			return out, ErrInvalidZone
+		}
+		ttl, err := strconv.ParseInt(r[2], 10, 0)
+		if err != nil {
+			fmt.Printf("failed to parse zone entry %q\n", scanner.Text())
+			return out, ErrInvalidZone
+		}
+		out = append(out, Host{Name: r[1], TTL: int(ttl), Type: r[3], Address: r[4]})
+	}
+	return out, err
+}
+
+const (
+	// Regexp to read zone entries
+	nsdRE = `^\s*(\S+)\s+(\d+)\s+(A|AAAA)\s+(\S+)\s*$`
+
+	// The zone file template
+	nsdZone = "{{range .}}{{.Name}}	{{.TTL}}	{{.Type}}	{{.Address}}\n{{end}}"
+)
diff --git a/nsd_test.go b/nsd_test.go
new file mode 100644
index 0000000..63bd658
--- /dev/null
+++ b/nsd_test.go
@@ -0,0 +1,88 @@
+package dyndns
+
+import (
+	"github.com/google/go-cmp/cmp"
+	"testing"
+)
+
+func TestNSDWrite(t *testing.T) {
+	nsd := nsdFormat{}
+
+	var tests = []struct {
+		in  interface{}
+		out interface{}
+	}{
+		{
+			in:  []Host{{Name: "test.com", TTL: 60, Type: "A", Address: "10.1.1.1"}},
+			out: []byte("test.com\t60\tA\t10.1.1.1\n"),
+		},
+		{
+			in: []Host{
+				{Name: "test.com", TTL: 60, Type: "A", Address: "10.1.1.1"},
+				{Name: "test2.com", TTL: 61, Type: "AAAA", Address: "10.1.1.2"},
+			},
+			out: []byte("test.com\t60\tA\t10.1.1.1\ntest2.com\t61\tAAAA\t10.1.1.2\n"),
+		},
+		{
+			in:  []Host{{Name: "test.com", TTL: 6, Type: "A", Address: "10.1.1.1"}},
+			out: []byte("test.com\t6\tA\t10.1.1.1\n"),
+		},
+	}
+
+	for _, tt := range tests {
+		r, err := nsd.Write(tt.in.([]Host))
+		if err != nil {
+			t.Errorf("Write(%q) failed, got %s\n", tt.in, err)
+		}
+		if !cmp.Equal(r, tt.out) {
+			t.Errorf("Write(%q) => %q, expected %q\n", tt.in, r, tt.out)
+		}
+	}
+}
+
+func TestNSDRead(t *testing.T) {
+	nsd := nsdFormat{}
+
+	var tests = []struct {
+		in  interface{}
+		out interface{}
+	}{
+		{
+			in:  []byte("test.com\t60\tA\t10.1.1.1\n"),
+			out: []Host{{Name: "test.com", TTL: 60, Type: "A", Address: "10.1.1.1"}},
+		},
+		{
+			in:  []byte("test.com   \t  60\t  \tA\t\t\t10.1.1.1\n"),
+			out: []Host{{Name: "test.com", TTL: 60, Type: "A", Address: "10.1.1.1"}},
+		},
+		{
+			in: []byte("test.com\t60\tA\t10.1.1.1\ntest2.com\t61\tAAAA\t10.1.1.2\n"),
+			out: []Host{
+				{Name: "test.com", TTL: 60, Type: "A", Address: "10.1.1.1"},
+				{Name: "test2.com", TTL: 61, Type: "AAAA", Address: "10.1.1.2"},
+			},
+		},
+		{
+			in:  []byte("test.com\t6\tA\t10.1.1.1\n"),
+			out: []Host{{Name: "test.com", TTL: 6, Type: "A", Address: "10.1.1.1"}},
+		},
+		{
+			in: []byte("test.com\tA\t10.1.1.1\n"),
+		},
+		{
+			in: []byte("test.com\t6 5\tA\t10.1.1.1\n"),
+		},
+	}
+
+	for _, tt := range tests {
+		r, err := nsd.Read(tt.in.([]byte))
+		if err == nil {
+			if !cmp.Equal(r, tt.out) {
+				t.Errorf("Read(%q) => %q %q, expected %q\n", tt.in, r, err, tt.out)
+
+			}
+		} else if tt.out != nil {
+			t.Errorf("Write(%q) failed, got %s\n", tt.in, err)
+		}
+	}
+}