Don't output trailing commas in dot attrs

Signed-off-by: Eric Chlebek <[email protected]>

dot/dot.go

@@ -3,9 +3,11 @@ package dot
 import (
 	"bytes"
 	"fmt"
-	"github.com/echlebek/goraph"
 	"io"
 	"sort"
+	"strings"
+
+	"github.com/echlebek/goraph"
 )
 
 const (
@@ -67,10 +69,11 @@ func writeAttrs(w *bytes.Buffer, name string, tabs int, attrs map[string]interfa
 		keys = append(keys, k)
 	}
 	sort.Sort(keys)
+	list := []string{}
 	for _, k := range keys {
-		fmt.Fprintf(w, "%s=%v, ", k, attrs[k])
+		list = append(list, fmt.Sprintf("%s=%v", k, attrs[k]))
 	}
-	fmt.Fprint(w, "];\n")
+	fmt.Fprintln(w, strings.Join(list, ", "), "];")
 }
 
 // WriteDot writes dot to w. It returns the number of bytes written and

dot/dot_test.go

@@ -2,8 +2,9 @@ package dot
 
 import (
 	"bytes"
-	"github.com/echlebek/goraph"
 	"testing"
+
+	"github.com/echlebek/goraph"
 )
 
 func TestDirectedDotWriter(t *testing.T) {
@@ -37,15 +38,15 @@ func TestDirectedDotWriter(t *testing.T) {
 	WriteDot(buf, dot)
 
 	expected := `digraph {
-	graph [ splines=false, ];
-	0 [ label=Happy, ];
-	1 [ label=Sleepy, shape=egg, ];
+	graph [ splines=false ];
+	0 [ label=Happy ];
+	1 [ label=Sleepy, shape=egg ];
 	1 -> 0;
 	1 -> 2;
 	3 -> 1;
 	4 -> 3;
 	4 -> 5;
-	5 -> 6 [ arrowhead=diamond, ];
+	5 -> 6 [ arrowhead=diamond ];
 	6 -> 7;
 	6 -> 9;
 	9 -> 8;