refactor(backend): extract to pkg/cap

pkg/mail/mail_test.go

@@ -0,0 +1,92 @@
+// Copyright 2025 linux.do
+// Copyright 2026 Arctel.net
+// SPDX-License-Identifier: Apache-2.0
+
+package mail
+
+import (
+	"bufio"
+	"context"
+	"net"
+	"net/textproto"
+	"testing"
+)
+
+func TestSendMailMock(t *testing.T) {
+	// Start a mock SMTP server
+	l, err := net.Listen("tcp", "127.0.0.1:0")
+	if err != nil {
+		t.Fatalf("failed to start mock smtp server: %v", err)
+	}
+	defer func() { _ = l.Close() }()
+
+	port := l.Addr().(*net.TCPAddr).Port
+
+	go func() {
+		conn, err := l.Accept()
+		if err != nil {
+			return
+		}
+		defer func() { _ = conn.Close() }()
+
+		writer := bufio.NewWriter(conn)
+		reader := bufio.NewReader(conn)
+		tp := textproto.NewReader(reader)
+
+		// 220 Ready
+		_, _ = writer.WriteString("220 mock.smtp.com SMTP Ready\r\n")
+		_ = writer.Flush()
+
+		// Read HELO/EHLO
+		_, _ = tp.ReadLine()
+		_, _ = writer.WriteString("250-mock.smtp.com\r\n250 AUTH PLAIN\r\n")
+		_ = writer.Flush()
+
+		// Read AUTH PLAIN
+		_, _ = tp.ReadLine()
+		_, _ = writer.WriteString("235 Authentication successful\r\n")
+		_ = writer.Flush()
+
+		// Read MAIL FROM
+		_, _ = tp.ReadLine()
+		_, _ = writer.WriteString("250 OK\r\n")
+		_ = writer.Flush()
+
+		// Read RCPT TO
+		_, _ = tp.ReadLine()
+		_, _ = writer.WriteString("250 OK\r\n")
+		_ = writer.Flush()
+
+		// Read DATA
+		_, _ = tp.ReadLine()
+		_, _ = writer.WriteString("354 Start mail input\r\n")
+		_ = writer.Flush()
+
+		// Read body lines until dot
+		for {
+			line, err := tp.ReadLine()
+			if err != nil || line == "." {
+				break
+			}
+		}
+		_, _ = writer.WriteString("250 OK\r\n")
+		_ = writer.Flush()
+
+		// Read QUIT
+		_, _ = tp.ReadLine()
+		_, _ = writer.WriteString("221 Bye\r\n")
+		_ = writer.Flush()
+	}()
+
+	cfg := Config{
+		Host:     "127.0.0.1",
+		Port:     port,
+		Username: "test@example.com",
+		Password: "password",
+	}
+
+	err = SendMail(context.Background(), cfg, "recipient@example.com", "Test Subject", "<h1>Test Body</h1>")
+	if err != nil {
+		t.Errorf("failed to send mail: %v", err)
+	}
+}