remove whitespace at beginning of new .netrc files

Fixes bgentry#5

Author: bgentry

netrc/netrc.go

@@ -90,6 +90,10 @@ func (n *Netrc) NewMachine(name, login, password, account string) *Machine {
 	n.updateLock.Lock()
 	defer n.updateLock.Unlock()
 
+	prefix := "\n"
+	if len(n.tokens) == 0 {
+		prefix = ""
+	}
 	m := &Machine{
 		Name:     name,
 		Login:    login,
@@ -98,7 +102,7 @@ func (n *Netrc) NewMachine(name, login, password, account string) *Machine {
 
 		nametoken: &token{
 			kind:     tkMachine,
-			rawkind:  []byte("\nmachine"),
+			rawkind:  []byte(prefix + "machine"),
 			value:    name,
 			rawvalue: []byte(" " + name),
 		},

netrc/netrc_test.go

@@ -271,6 +271,12 @@ func testNewMachine(t *testing.T, n *Netrc) {
 			}
 		}
 
+		// test prefix for machine token
+		prefix := "\n"
+		if len(n.tokens) == 0 {
+			prefix = ""
+		}
+
 		m := n.NewMachine(test.name, test.login, test.password, test.account)
 		if m == nil {
 			t.Fatalf("NewMachine() returned nil")
@@ -293,7 +299,7 @@ func testNewMachine(t *testing.T, n *Netrc) {
 			t.Errorf("m.Account expected %q, got %q", test.account, m.Account)
 		}
 		// check tokens
-		checkToken(t, "nametoken", m.nametoken, tkMachine, "\nmachine", test.name)
+		checkToken(t, "nametoken", m.nametoken, tkMachine, prefix+"machine", test.name)
 		checkToken(t, "logintoken", m.logintoken, tkLogin, "\n\tlogin", test.login)
 		checkToken(t, "passtoken", m.passtoken, tkPassword, "\n\tpassword", test.password)
 		checkToken(t, "accounttoken", m.accounttoken, tkAccount, "\n\taccount", test.account)
@@ -510,6 +516,32 @@ func TestUpdatePassword(t *testing.T) {
 	}
 }
 
+func TestNewFile(t *testing.T) {
+	var n Netrc
+
+	result, err := n.MarshalText()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if string(result) != "" {
+		t.Errorf("expected empty result=\"\", got %q", string(result))
+	}
+
+	n.NewMachine("netrctest.heroku.com", "auser", "apassword", "")
+
+	result, err = n.MarshalText()
+	if err != nil {
+		t.Fatal(err)
+	}
+	expected := `machine netrctest.heroku.com
+	login auser
+	password apassword`
+
+	if string(result) != expected {
+		t.Errorf("expected result:\n%q\ngot:\n%q", expected, string(result))
+	}
+}
+
 func netrcReader(filename string, t *testing.T) io.Reader {
 	b, err := ioutil.ReadFile(filename)
 	if err != nil {