add a Clone function

config.go

@@ -110,3 +110,19 @@ func ToMap(conf *Config) (map[string]interface{}, error) {
 	}
 	return m, nil
 }
+
+// Clone copies the config. Use when updating.
+func (c *Config) Clone() (*Config, error) {
+	var newConfig Config
+	var buf bytes.Buffer
+
+	if err := json.NewEncoder(&buf).Encode(c); err != nil {
+		return nil, fmt.Errorf("failure to encode config: %s", err)
+	}
+
+	if err := json.NewDecoder(&buf).Decode(&newConfig); err != nil {
+		return nil, fmt.Errorf("failure to decode config: %s", err)
+	}
+
+	return &newConfig, nil
+}

config_test.go

@@ -0,0 +1,29 @@
+package config
+
+import (
+	"testing"
+)
+
+func TestClone(t *testing.T) {
+	c := new(Config)
+	c.Identity.PeerID = "faketest"
+	c.API.HTTPHeaders = map[string][]string{"foo": {"bar"}}
+
+	newCfg, err := c.Clone()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if newCfg.Identity.PeerID != c.Identity.PeerID {
+		t.Fatal("peer ID not preserved")
+	}
+
+	c.API.HTTPHeaders["foo"] = []string{"baz"}
+	if newCfg.API.HTTPHeaders["foo"][0] != "bar" {
+		t.Fatal("HTTP headers not preserved")
+	}
+
+	delete(c.API.HTTPHeaders, "foo")
+	if newCfg.API.HTTPHeaders["foo"][0] != "bar" {
+		t.Fatal("HTTP headers not preserved")
+	}
+}

types_test.go

@@ -0,0 +1,53 @@
+package config
+
+import (
+	"encoding/json"
+	"testing"
+)
+
+func TestOneStrings(t *testing.T) {
+	out, err := json.Marshal(Strings{"one"})
+	if err != nil {
+		t.Fatal(err)
+
+	}
+	expected := "\"one\""
+	if string(out) != expected {
+		t.Fatalf("expected %s, got %s", expected, string(out))
+	}
+}
+
+func TestNoStrings(t *testing.T) {
+	out, err := json.Marshal(Strings{})
+	if err != nil {
+		t.Fatal(err)
+
+	}
+	expected := "null"
+	if string(out) != expected {
+		t.Fatalf("expected %s, got %s", expected, string(out))
+	}
+}
+
+func TestManyStrings(t *testing.T) {
+	out, err := json.Marshal(Strings{"one", "two"})
+	if err != nil {
+		t.Fatal(err)
+
+	}
+	expected := "[\"one\",\"two\"]"
+	if string(out) != expected {
+		t.Fatalf("expected %s, got %s", expected, string(out))
+	}
+}
+
+func TestFunkyStrings(t *testing.T) {
+	toParse := " [   \"one\",   \"two\" ]  "
+	var s Strings
+	if err := json.Unmarshal([]byte(toParse), &s); err != nil {
+		t.Fatal(err)
+	}
+	if len(s) != 2 || s[0] != "one" && s[1] != "two" {
+		t.Fatalf("unexpected result: %v", s)
+	}
+}