setters: q-encode headers according to RFC1342

Encodes non-ASCII characters using the Q-encoding specified in RFC1342.

    https://tools.ietf.org/html/rfc1342

Fixes #19.

setters.go

@@ -1,5 +1,7 @@
 package mailyak
 
+import "mime"
+
 // To sets a list of recipient addresses.
 //
 // You can pass one or more addresses to this method, all of which are viewable to the recipients.
@@ -115,8 +117,9 @@ func (m *MailYak) From(addr string) {
 //
 // 		From Name <[email protected]>
 //
+// If name contains non-ASCII characters, it is Q-encoded according to RFC1342.
 func (m *MailYak) FromName(name string) {
-	m.fromName = m.trimRegex.ReplaceAllString(name, "")
+	m.fromName = mime.QEncoding.Encode("UTF-8", m.trimRegex.ReplaceAllString(name, ""))
 }
 
 // ReplyTo sets the Reply-To email address.
@@ -127,6 +130,8 @@ func (m *MailYak) ReplyTo(addr string) {
 }
 
 // Subject sets the email subject line.
+//
+// If sub contains non-ASCII characters, it is Q-encoded according to RFC1342.
 func (m *MailYak) Subject(sub string) {
-	m.subject = m.trimRegex.ReplaceAllString(sub, "")
+	m.subject = mime.QEncoding.Encode("UTF-8", m.trimRegex.ReplaceAllString(sub, ""))
 }

setters_test.go

@@ -105,3 +105,80 @@ func TestMailYakBcc(t *testing.T) {
 		})
 	}
 }
+func TestMailYakSubject(t *testing.T) {
+	t.Parallel()
+
+	tests := []struct {
+		// Test description.
+		name string
+		// Parameters.
+		subject string
+		// Want
+		want string
+	}{
+		{
+			"ASCII",
+			"Banana\r\n",
+			"Banana",
+		},
+		{
+			"Q-encoded",
+			"🍌\r\n",
+			"=?UTF-8?q?=F0=9F=8D=8C?=",
+		},
+	}
+	for _, tt := range tests {
+		tt := tt
+		t.Run(tt.name, func(t *testing.T) {
+			t.Parallel()
+
+			m := &MailYak{
+				trimRegex: regexp.MustCompile("\r?\n"),
+			}
+			m.Subject(tt.subject)
+
+			if !reflect.DeepEqual(m.subject, tt.want) {
+				t.Errorf("%q. MailYak.Subject() = %v, want %v", tt.name, m.subject, tt.want)
+			}
+		})
+	}
+}
+
+func TestMailYakFromName(t *testing.T) {
+	t.Parallel()
+
+	tests := []struct {
+		// Test description.
+		name string
+		// Parameters.
+		from string
+		// Want
+		want string
+	}{
+		{
+			"ASCII",
+			"Goat\r\n",
+			"Goat",
+		},
+		{
+			"Q-encoded",
+			"🐐",
+			"=?UTF-8?q?=F0=9F=90=90?=",
+		},
+	}
+	for _, tt := range tests {
+		tt := tt
+		t.Run(tt.name, func(t *testing.T) {
+			t.Parallel()
+
+			m := &MailYak{
+				trimRegex: regexp.MustCompile("\r?\n"),
+			}
+			m.FromName(tt.from)
+
+			if !reflect.DeepEqual(m.fromName, tt.want) {
+				t.Errorf("%q. MailYak.Subject() = %v, want %v", tt.name, m.fromName, tt.want)
+			}
+		})
+	}
+}