dotnet unit tests

tests/Application.UnitTest/Services/EmailServiceTests.cs

@@ -0,0 +1,60 @@
+using Application.Models;
+using Application.Services;
+using MailKit.Net.Smtp;
+using Microsoft.Extensions.Configuration;
+using MimeKit;
+using NSubstitute;
+
+namespace Application.UnitTest.Services;
+
+public class EmailServiceTests
+{
+    private readonly IConfiguration _configuration = Substitute.For<IConfiguration>();
+    private readonly ISmtpClient _smtpClient = Substitute.For<ISmtpClient>();
+    private readonly EmailService _sut;
+
+    public EmailServiceTests()
+    {
+        _configuration["EmailSettings:From"].Returns("sender@gmail.com");
+        _configuration["EmailSettings:SmtpServer"].Returns("smtp.gmail.com");
+        _configuration["EmailSettings:Password"].Returns("app-password");
+
+        _sut = new EmailService(_configuration, () => _smtpClient);
+    }
+
+    [Fact]
+    public void SendEmailAsync_ShouldConnectAndAuthenticate()
+    {
+        var request = new EmailRequest("recipient@example.com", "Test Subject", "<p>Hello</p>");
+
+        _sut.SendEmailAsync(request);
+
+        _smtpClient.Received(1).Connect("smtp.gmail.com", 465, true);
+        _smtpClient.Received(1).Authenticate("sender@gmail.com", "app-password");
+        _smtpClient.Received(1).Send(Arg.Any<MimeMessage>());
+        _smtpClient.Received(1).Disconnect(true);
+    }
+
+    [Fact]
+    public void SendEmailAsync_ShouldSendMessageWithCorrectDetails()
+    {
+        var request = new EmailRequest("recipient@example.com", "Welcome!", "<h1>Hi</h1>");
+
+        _sut.SendEmailAsync(request);
+
+        _smtpClient.Received(1).Send(Arg.Is<MimeMessage>(msg =>
+            msg.To.Mailboxes.Any(m => m.Address == "recipient@example.com") &&
+            msg.Subject == "Welcome!"));
+    }
+
+    [Fact]
+    public void SendEmailAsync_ShouldDisposeClient_AfterSending()
+    {
+        var request = new EmailRequest("recipient@example.com", "Subject", "Body");
+
+        _sut.SendEmailAsync(request);
+
+        _smtpClient.Received(1).Disconnect(true);
+        _smtpClient.Received(1).Dispose();
+    }
+}