Extensions instead of partial classes

CHANGELOG.md

@@ -7,7 +7,14 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
-_No changes yet_
+### Added
+
+- `Validation` utility class for specifications as MSISDN
+
+### Changed
+
+- Channel implementations (SMS, WhatsApp, ...) are extensions to the `ILinkMobilityClient` interface.
+
 
 ## [v0.1.1] - 2026-03-13
 

src/LinkMobility/ILinkMobilityClient.cs

@@ -9,17 +9,14 @@ namespace AMWD.Net.Api.LinkMobility
 	public interface ILinkMobilityClient
 	{
 		/// <summary>
-		/// Sends a text message to a list of recipients.
+		/// Performs a POST request to the LINK mobility API.
 		/// </summary>
+		/// <typeparam name="TResponse">The type of the response.</typeparam>
+		/// <typeparam name="TRequest">The type of the request.</typeparam>
+		/// <param name="requestPath">The path of the API endpoint.</param>
 		/// <param name="request">The request data.</param>
+		/// <param name="queryParams">Optional query parameters.</param>
 		/// <param name="cancellationToken">A cancellation token to propagate notification that operations should be canceled.</param>
-		Task<SendMessageResponse> SendTextMessage(SendTextMessageRequest request, CancellationToken cancellationToken = default);
+		Task<TResponse> PostAsync<TResponse, TRequest>(string requestPath, TRequest? request, IQueryParameter? queryParams = null, CancellationToken cancellationToken = default);
-
-		/// <summary>
-		/// Sends a binary message to a list of recipients.
-		/// </summary>
-		/// <param name="request">The request data.</param>
-		/// <param name="cancellationToken">A cancellation token to propagate notification that operations should be canceled.</param>
-		Task<SendMessageResponse> SendBinaryMessage(SendBinaryMessageRequest request, CancellationToken cancellationToken = default);
 	}
 }

src/LinkMobility/LinkMobilityClient.Sms.cs

@@ -1,68 +0,0 @@
-using System.Text.RegularExpressions;
-using System.Threading;
-using System.Threading.Tasks;
-
-namespace AMWD.Net.Api.LinkMobility
-{
-	/// <summary>
-	/// Implementation of text messaging (SMS). <see href="https://developer.linkmobility.eu/sms-api/rest-api">API</see>
-	/// </summary>
-	public partial class LinkMobilityClient : ILinkMobilityClient, IDisposable
-	{
-		/// <inheritdoc/>
-		public Task<SendMessageResponse> SendTextMessage(SendTextMessageRequest request, CancellationToken cancellationToken = default)
-		{
-			if (request == null)
-				throw new ArgumentNullException(nameof(request));
-
-			if (string.IsNullOrWhiteSpace(request.MessageContent))
-				throw new ArgumentException("A message must be provided.", nameof(request.MessageContent));
-
-			if (request.RecipientAddressList == null || request.RecipientAddressList.Count == 0)
-				throw new ArgumentException("At least one recipient must be provided.", nameof(request.RecipientAddressList));
-
-			foreach (string recipient in request.RecipientAddressList)
-			{
-				if (!IsValidMSISDN(recipient))
-					throw new ArgumentException($"Recipient address '{recipient}' is not a valid MSISDN format.", nameof(request.RecipientAddressList));
-			}
-
-			return PostAsync<SendMessageResponse, SendTextMessageRequest>("/smsmessaging/text", request, cancellationToken: cancellationToken);
-		}
-
-		/// <inheritdoc/>
-		public Task<SendMessageResponse> SendBinaryMessage(SendBinaryMessageRequest request, CancellationToken cancellationToken = default)
-		{
-			if (request == null)
-				throw new ArgumentNullException(nameof(request));
-
-			if (request.MessageContent?.Count > 0)
-			{
-				// Validate that the string is a valid Base64 string
-				// Might throw a ArgumentNullException or FormatException
-				foreach (string str in request.MessageContent)
-					Convert.FromBase64String(str);
-			}
-
-			if (request.RecipientAddressList == null || request.RecipientAddressList.Count == 0)
-				throw new ArgumentException("At least one recipient must be provided.", nameof(request.RecipientAddressList));
-
-			foreach (string recipient in request.RecipientAddressList)
-			{
-				if (!IsValidMSISDN(recipient))
-					throw new ArgumentException($"Recipient address '{recipient}' is not a valid MSISDN format.", nameof(request.RecipientAddressList));
-			}
-
-			return PostAsync<SendMessageResponse, SendBinaryMessageRequest>("/smsmessaging/binary", request, cancellationToken: cancellationToken);
-		}
-
-		// https://en.wikipedia.org/wiki/MSISDN
-		private static bool IsValidMSISDN(string msisdn)
-		{
-			if (string.IsNullOrWhiteSpace(msisdn))
-				return false;
-
-			return Regex.IsMatch(msisdn, @"^[1-9][0-9]{7,14}$", RegexOptions.Compiled);
-		}
-	}
-}

src/LinkMobility/LinkMobilityClient.cs

@@ -13,7 +13,7 @@ namespace AMWD.Net.Api.LinkMobility
 	/// <summary>
 	/// Provides a client for interacting with the Link Mobility API.
 	/// </summary>
-	public partial class LinkMobilityClient : ILinkMobilityClient, IDisposable
+	public class LinkMobilityClient : ILinkMobilityClient, IDisposable
 	{
 		private readonly ClientOptions _clientOptions;
 		private readonly HttpClient _httpClient;
@@ -78,6 +78,52 @@ namespace AMWD.Net.Api.LinkMobility
 			GC.SuppressFinalize(this);
 		}
 
+		/// <inheritdoc/>
+		public async Task<TResponse> PostAsync<TResponse, TRequest>(string requestPath, TRequest? request, IQueryParameter? queryParams = null, CancellationToken cancellationToken = default)
+		{
+			ThrowIfDisposed();
+			ValidateRequestPath(requestPath);
+
+			string requestUrl = BuildRequestUrl(requestPath, queryParams);
+			var httpContent = ConvertRequest(request);
+
+			var httpRequest = new HttpRequestMessage
+			{
+				Method = HttpMethod.Post,
+				RequestUri = new Uri(requestUrl, UriKind.Relative),
+				Content = httpContent,
+			};
+
+			var httpResponse = await _httpClient.SendAsync(httpRequest, cancellationToken).ConfigureAwait(false);
+			var response = await GetResponse<TResponse>(httpResponse, cancellationToken).ConfigureAwait(false);
+			return response;
+		}
+
+		private string BuildRequestUrl(string requestPath, IQueryParameter? queryParams = null)
+		{
+			string path = requestPath.Trim().TrimStart('/');
+			var param = new Dictionary<string, string>();
+
+			if (_clientOptions.DefaultQueryParams.Count > 0)
+			{
+				foreach (var kvp in _clientOptions.DefaultQueryParams)
+					param[kvp.Key] = kvp.Value;
+			}
+
+			var customQueryParams = queryParams?.GetQueryParameters();
+			if (customQueryParams?.Count > 0)
+			{
+				foreach (var kvp in customQueryParams)
+					param[kvp.Key] = kvp.Value;
+			}
+
+			if (param.Count == 0)
+				return path;
+
+			string queryString = string.Join("&", param.Select(kvp => $"{WebUtility.UrlEncode(kvp.Key)}={WebUtility.UrlEncode(kvp.Value)}"));
+			return $"{path}?{queryString}";
+		}
+
 		private void ValidateClientOptions()
 		{
 			if (string.IsNullOrWhiteSpace(_clientOptions.BaseUrl))
@@ -148,51 +194,6 @@ namespace AMWD.Net.Api.LinkMobility
 			}
 		}
 
-		private async Task<TResponse> PostAsync<TResponse, TRequest>(string requestPath, TRequest? request, IQueryParameter? queryParams = null, CancellationToken cancellationToken = default)
-		{
-			ThrowIfDisposed();
-			ValidateRequestPath(requestPath);
-
-			string requestUrl = BuildRequestUrl(requestPath, queryParams);
-			var httpContent = ConvertRequest(request);
-
-			var httpRequest = new HttpRequestMessage
-			{
-				Method = HttpMethod.Post,
-				RequestUri = new Uri(requestUrl, UriKind.Relative),
-				Content = httpContent,
-			};
-
-			var httpResponse = await _httpClient.SendAsync(httpRequest, cancellationToken).ConfigureAwait(false);
-			var response = await GetResponse<TResponse>(httpResponse, cancellationToken).ConfigureAwait(false);
-			return response;
-		}
-
-		private string BuildRequestUrl(string requestPath, IQueryParameter? queryParams = null)
-		{
-			string path = requestPath.Trim().TrimStart('/');
-			var param = new Dictionary<string, string>();
-
-			if (_clientOptions.DefaultQueryParams.Count > 0)
-			{
-				foreach (var kvp in _clientOptions.DefaultQueryParams)
-					param[kvp.Key] = kvp.Value;
-			}
-
-			var customQueryParams = queryParams?.GetQueryParameters();
-			if (customQueryParams?.Count > 0)
-			{
-				foreach (var kvp in customQueryParams)
-					param[kvp.Key] = kvp.Value;
-			}
-
-			if (param.Count == 0)
-				return path;
-
-			string queryString = string.Join("&", param.Select(kvp => $"{WebUtility.UrlEncode(kvp.Key)}={WebUtility.UrlEncode(kvp.Value)}"));
-			return $"{path}?{queryString}";
-		}
-
 		private static HttpContent? ConvertRequest<T>(T request)
 		{
 			if (request == null)

src/LinkMobility/Models/IncomingMessageNotification.cs

@@ -56,7 +56,7 @@ namespace AMWD.Net.Api.LinkMobility
 		/// <summary>
 		/// <see cref="Type.Text"/>, <see cref="Type.Binary"/>:
 		/// <br/>
-		/// <see cref="AddressType.International"/> – defines the number format of the mobile originated <see cref="SenderAddress"/>.
+		/// <see cref="AddressType.International"/> - defines the number format of the mobile originated <see cref="SenderAddress"/>.
 		/// International numbers always includes the country prefix.
 		/// </summary>
 		[JsonProperty("senderAddressType")]

src/LinkMobility/Requests/SendBinaryMessageRequest.cs

@@ -8,9 +8,11 @@
 		/// <summary>
 		/// Initializes a new instance of the <see cref="SendBinaryMessageRequest"/> class.
 		/// </summary>
-		/// <param name="recipientAddressList">The recipient list.</param>
+		/// <param name="messageContent">A binary message as base64 encoded lines.</param>
-		public SendBinaryMessageRequest(IReadOnlyCollection<string> recipientAddressList)
+		/// <param name="recipientAddressList">A list of recipient numbers.</param>
+		public SendBinaryMessageRequest(IReadOnlyCollection<string> messageContent, IReadOnlyCollection<string> recipientAddressList)
 		{
+			MessageContent = messageContent;
 			RecipientAddressList = recipientAddressList;
 		}
 
@@ -41,7 +43,7 @@
 		/// The binary data is transmitted without being changed (using 8 bit alphabet).
 		/// </remarks>
 		[JsonProperty("messageContent")]
-		public IReadOnlyCollection<string>? MessageContent { get; set; }
+		public IReadOnlyCollection<string> MessageContent { get; set; }
 
 		/// <summary>
 		/// <em>Optional</em>.

src/LinkMobility/Requests/SendTextMessageRequest.cs

@@ -8,8 +8,8 @@
 		/// <summary>
 		/// Initializes a new instance of the <see cref="SendTextMessageRequest"/> class.
 		/// </summary>
-		/// <param name="messageContent">The message.</param>
+		/// <param name="messageContent">A text message.</param>
-		/// <param name="recipientAddressList">The recipient list.</param>
+		/// <param name="recipientAddressList">A list of recipient numbers.</param>
 		public SendTextMessageRequest(string messageContent, IReadOnlyCollection<string> recipientAddressList)
 		{
 			MessageContent = messageContent;

src/LinkMobility/Responses/SendMessageResponse.cs

@@ -11,12 +11,6 @@
 		[JsonProperty("clientMessageId")]
 		public string? ClientMessageId { get; set; }
 
-		/// <summary>
-		/// The actual number of generated SMS.
-		/// </summary>
-		[JsonProperty("smsCount")]
-		public int? SmsCount { get; set; }
-
 		/// <summary>
 		/// Status code.
 		/// </summary>

src/LinkMobility/Responses/SendTextMessageResponse.cs

@@ -0,0 +1,14 @@
+namespace AMWD.Net.Api.LinkMobility
+{
+	/// <summary>
+	/// Response of a text message sent to a list of recipients.
+	/// </summary>
+	public class SendTextMessageResponse : SendMessageResponse
+	{
+		/// <summary>
+		/// The actual number of generated SMS.
+		/// </summary>
+		[JsonProperty("smsCount")]
+		public int? SmsCount { get; set; }
+	}
+}

src/LinkMobility/TextMessageExtensions.cs

@@ -0,0 +1,78 @@
+using System.Threading;
+using System.Threading.Tasks;
+using AMWD.Net.Api.LinkMobility.Utils;
+
+namespace AMWD.Net.Api.LinkMobility
+{
+	/// <summary>
+	/// Implementation of text messaging (SMS). <see href="https://developer.linkmobility.eu/sms-api/rest-api">API</see>
+	/// </summary>
+	public static class TextMessageExtensions
+	{
+		/// <summary>
+		/// Sends a text message to a list of recipients.
+		/// </summary>
+		/// <param name="client">The <see cref="ILinkMobilityClient"/> instance.</param>
+		/// <param name="request">The request data.</param>
+		/// <param name="cancellationToken">A cancellation token to propagate notification that operations should be canceled.</param>
+		public static Task<SendTextMessageResponse> SendTextMessage(this ILinkMobilityClient client, SendTextMessageRequest request, CancellationToken cancellationToken = default)
+		{
+			if (request == null)
+				throw new ArgumentNullException(nameof(request));
+
+			if (string.IsNullOrWhiteSpace(request.MessageContent))
+				throw new ArgumentException("A message must be provided.", nameof(request.MessageContent));
+
+			ValidateRecipientList(request.RecipientAddressList);
+			ValidateContentCategory(request.ContentCategory);
+
+			return client.PostAsync<SendTextMessageResponse, SendTextMessageRequest>("/smsmessaging/text", request, cancellationToken: cancellationToken);
+		}
+
+		/// <summary>
+		/// Sends a binary message to a list of recipients.
+		/// </summary>
+		/// <param name="client">The <see cref="ILinkMobilityClient"/> instance.</param>
+		/// <param name="request">The request data.</param>
+		/// <param name="cancellationToken">A cancellation token to propagate notification that operations should be canceled.</param>
+		public static Task<SendTextMessageResponse> SendBinaryMessage(this ILinkMobilityClient client, SendBinaryMessageRequest request, CancellationToken cancellationToken = default)
+		{
+			if (request == null)
+				throw new ArgumentNullException(nameof(request));
+
+			if (request.MessageContent == null || request.MessageContent.Count == 0)
+				throw new ArgumentException("A message must be provided.", nameof(request.MessageContent));
+
+			// Easiest way to validate that the string is a valid Base64 string.
+			// Might throw a ArgumentNullException or FormatException.
+			foreach (string str in request.MessageContent)
+				Convert.FromBase64String(str);
+
+			ValidateRecipientList(request.RecipientAddressList);
+			ValidateContentCategory(request.ContentCategory);
+
+			return client.PostAsync<SendTextMessageResponse, SendBinaryMessageRequest>("/smsmessaging/binary", request, cancellationToken: cancellationToken);
+		}
+
+		private static void ValidateRecipientList(IReadOnlyCollection<string>? recipientAddressList)
+		{
+			if (recipientAddressList == null || recipientAddressList.Count == 0)
+				throw new ArgumentException("At least one recipient must be provided.", nameof(recipientAddressList));
+
+			foreach (string recipient in recipientAddressList)
+			{
+				if (!Validation.IsValidMSISDN(recipient))
+					throw new ArgumentException($"Recipient address '{recipient}' is not a valid MSISDN format.", nameof(recipientAddressList));
+			}
+		}
+
+		private static void ValidateContentCategory(ContentCategory? contentCategory)
+		{
+			if (!contentCategory.HasValue)
+				return;
+
+			if (contentCategory.Value != ContentCategory.Informational && contentCategory.Value != ContentCategory.Advertisement)
+				throw new ArgumentException($"Content category '{contentCategory.Value}' is not valid.", nameof(contentCategory));
+		}
+	}
+}

src/LinkMobility/Utils/Validation.cs

@@ -0,0 +1,25 @@
+using System.Text.RegularExpressions;
+
+namespace AMWD.Net.Api.LinkMobility.Utils
+{
+	/// <summary>
+	/// Validation helper for LINK Mobility API requirements.
+	/// </summary>
+	public static class Validation
+	{
+		/// <summary>
+		/// Validates whether the provided string is a valid MSISDN (E.164 formatted).
+		/// <br/>
+		/// See <see href="https://en.wikipedia.org/wiki/MSISDN">Wikipedia: MSISDN</see> for more information.
+		/// </summary>
+		/// <param name="msisdn">The string to validate.</param>
+		/// <returns><see langword="true"/> for a valid MSISDN number, <see langword="false"/> otherwise.</returns>
+		public static bool IsValidMSISDN(string msisdn)
+		{
+			if (string.IsNullOrWhiteSpace(msisdn))
+				return false;
+
+			return Regex.IsMatch(msisdn, @"^[1-9][0-9]{7,14}$", RegexOptions.Compiled);
+		}
+	}
+}

test/LinkMobility.Tests/Helpers/HttpMessageHandlerMock.cs

@@ -39,6 +39,8 @@ namespace LinkMobility.Tests.Helpers
 		public Queue<HttpResponseMessage> Responses { get; } = new();
 
 		public Mock<HttpClientHandler> Mock { get; }
+
+		public IProtectedMock<HttpClientHandler> Protected => Mock.Protected();
 	}
 
 	internal class HttpRequestMessageCallback

test/LinkMobility.Tests/LinkMobilityClientTest.cs

@@ -145,7 +145,7 @@ namespace LinkMobility.Tests
 			var client = GetClient();
 
 			// Act
-			var response = await ReflectionHelper.InvokePrivateMethodAsync<TestClass>(client, "PostAsync", "test", _request, null, TestContext.CancellationToken);
+			var response = await client.PostAsync<TestClass, TestClass>("test", _request, null, TestContext.CancellationToken);
 
 			// Assert
 			Assert.IsNotNull(response);
@@ -188,7 +188,7 @@ namespace LinkMobility.Tests
 			var client = GetClient();
 
 			// Act
-			var response = await ReflectionHelper.InvokePrivateMethodAsync<TestClass>(client, "PostAsync", "params/path", _request, queryParams, TestContext.CancellationToken);
+			var response = await client.PostAsync<TestClass, TestClass>("params/path", _request, queryParams, TestContext.CancellationToken);
 
 			// Assert
 			Assert.IsNotNull(response);
@@ -256,7 +256,7 @@ namespace LinkMobility.Tests
 		public void ShouldAssertClientOptions()
 		{
 			// Arrange + Act
-			var client = GetClient();
+			_ = GetClient();
 
 			// Assert
 			VerifyNoOtherCalls();
@@ -320,7 +320,7 @@ namespace LinkMobility.Tests
 			// Act & Assert
 			await Assert.ThrowsExactlyAsync<ObjectDisposedException>(async () =>
 			{
-				await ReflectionHelper.InvokePrivateMethodAsync<object>(client, "PostAsync", "/request/path", _request, null, TestContext.CancellationToken);
+				await client.PostAsync<object, TestClass>("/request/path", _request, null, TestContext.CancellationToken);
 			});
 		}
 
@@ -336,7 +336,7 @@ namespace LinkMobility.Tests
 			// Act & Assert
 			await Assert.ThrowsExactlyAsync<ArgumentNullException>(async () =>
 			{
-				await ReflectionHelper.InvokePrivateMethodAsync<object>(client, "PostAsync", path, _request, null, TestContext.CancellationToken);
+				await client.PostAsync<object, TestClass>(path, _request, null, TestContext.CancellationToken);
 			});
 		}
 
@@ -349,7 +349,7 @@ namespace LinkMobility.Tests
 			// Act & Assert
 			await Assert.ThrowsExactlyAsync<ArgumentException>(async () =>
 			{
-				await ReflectionHelper.InvokePrivateMethodAsync<object>(client, "PostAsync", "foo?bar=baz", _request, null, TestContext.CancellationToken);
+				await client.PostAsync<object, TestClass>("foo?bar=baz", _request, null, TestContext.CancellationToken);
 			});
 		}
 
@@ -366,7 +366,7 @@ namespace LinkMobility.Tests
 			var client = GetClient();
 
 			// Act
-			var response = await ReflectionHelper.InvokePrivateMethodAsync<TestClass>(client, "PostAsync", "/request/path", _request, null, TestContext.CancellationToken);
+			var response = await client.PostAsync<TestClass, TestClass>("/request/path", _request, null, TestContext.CancellationToken);
 
 			// Assert
 			Assert.IsNotNull(response);
@@ -411,7 +411,7 @@ namespace LinkMobility.Tests
 			var client = GetClient();
 
 			// Act
-			var response = await ReflectionHelper.InvokePrivateMethodAsync<TestClass>(client, "PostAsync", "/request/path", stringContent, null, TestContext.CancellationToken);
+			var response = await client.PostAsync<TestClass, HttpContent>("/request/path", stringContent, null, TestContext.CancellationToken);
 
 			// Assert
 			Assert.IsNotNull(response);
@@ -455,7 +455,7 @@ namespace LinkMobility.Tests
 			var client = GetClient();
 
 			// Act
-			var response = await ReflectionHelper.InvokePrivateMethodAsync<TestClass>(client, "PostAsync", "posting", null, null, TestContext.CancellationToken);
+			var response = await client.PostAsync<TestClass, object>("posting", null, null, TestContext.CancellationToken);
 
 			// Assert
 			Assert.IsNotNull(response);
@@ -501,7 +501,7 @@ namespace LinkMobility.Tests
 			// Act & Assert
 			var ex = await Assert.ThrowsExactlyAsync<AuthenticationException>(async () =>
 			{
-				await ReflectionHelper.InvokePrivateMethodAsync<object>(client, "PostAsync", "foo", _request, null, TestContext.CancellationToken);
+				await client.PostAsync<object, TestClass>("foo", _request, null, TestContext.CancellationToken);
 			});
 			Assert.IsNull(ex.InnerException);
 			Assert.AreEqual($"HTTP auth missing: {statusCode}", ex.Message);
@@ -524,7 +524,7 @@ namespace LinkMobility.Tests
 			// Act & Assert
 			var ex = await Assert.ThrowsExactlyAsync<ApplicationException>(async () =>
 			{
-				await ReflectionHelper.InvokePrivateMethodAsync<object>(client, "PostAsync", "foo", _request, null, TestContext.CancellationToken);
+				await client.PostAsync<object, TestClass>("foo", _request, null, TestContext.CancellationToken);
 			});
 			Assert.IsNull(ex.InnerException);
 			Assert.AreEqual($"Unknown HTTP response: {statusCode}", ex.Message);
@@ -545,7 +545,7 @@ namespace LinkMobility.Tests
 			// Act & Assert
 			await Assert.ThrowsExactlyAsync<JsonReaderException>(async () =>
 			{
-				await ReflectionHelper.InvokePrivateMethodAsync<TestClass>(client, "PostAsync", "some-path", _request, null, TestContext.CancellationToken);
+				await client.PostAsync<TestClass, TestClass>("some-path", _request, null, TestContext.CancellationToken);
 			});
 		}
 
@@ -563,7 +563,7 @@ namespace LinkMobility.Tests
 			var client = GetClient();
 
 			// Act
-			string response = await ReflectionHelper.InvokePrivateMethodAsync<string>(client, "PostAsync", "path", _request, null, TestContext.CancellationToken);
+			string response = await client.PostAsync<string, TestClass>("path", _request, null, TestContext.CancellationToken);
 
 			// Assert
 			Assert.IsNotNull(response);

test/LinkMobility.Tests/Sms/SendBinaryMessageTest.cs

@@ -42,10 +42,7 @@ namespace LinkMobility.Tests.Sms
 			_clientOptionsMock.Setup(c => c.AllowRedirects).Returns(true);
 			_clientOptionsMock.Setup(c => c.UseProxy).Returns(false);
 
-			_request = new SendBinaryMessageRequest(["436991234567"])
+			_request = new SendBinaryMessageRequest(["SGVsbG8gV29ybGQ="], ["436991234567"]); // "Hello World" in Base64
-			{
-				MessageContent = ["SGVsbG8gV29ybGQ="] // "Hello World" base64
-			};
 		}
 
 		[TestMethod]
@@ -87,14 +84,27 @@ namespace LinkMobility.Tests.Sms
 			Assert.AreEqual("Scheme Parameter", callback.Headers["Authorization"]);
 			Assert.AreEqual("LinkMobilityClient/1.0.0", callback.Headers["User-Agent"]);
 
-			_httpMessageHandlerMock.Mock
+			_httpMessageHandlerMock.Protected.Verify("SendAsync", Times.Once(), ItExpr.IsAny<HttpRequestMessage>(), ItExpr.IsAny<CancellationToken>());
-				.Protected()
-				.Verify("SendAsync", Times.Once(), ItExpr.IsAny<HttpRequestMessage>(), ItExpr.IsAny<CancellationToken>());
 
 			_clientOptionsMock.VerifyGet(o => o.DefaultQueryParams, Times.Once);
 			VerifyNoOtherCalls();
 		}
 
+		[TestMethod]
+		public void ShouldThrowOnInvalidContentCategoryForBinary()
+		{
+			// Arrange
+			_request.ContentCategory = 0;
+			var client = GetClient();
+
+			// Act & Assert
+			var ex = Assert.ThrowsExactly<ArgumentException>(() => client.SendBinaryMessage(_request, TestContext.CancellationToken));
+			Assert.AreEqual("contentCategory", ex.ParamName);
+			Assert.StartsWith("Content category '0' is not valid.", ex.Message);
+
+			VerifyNoOtherCalls();
+		}
+
 		[TestMethod]
 		public async Task ShouldSendBinaryMessageFullDetails()
 		{
@@ -145,9 +155,7 @@ namespace LinkMobility.Tests.Sms
 			Assert.AreEqual("Scheme Parameter", callback.Headers["Authorization"]);
 			Assert.AreEqual("LinkMobilityClient/1.0.0", callback.Headers["User-Agent"]);
 
-			_httpMessageHandlerMock.Mock
+			_httpMessageHandlerMock.Protected.Verify("SendAsync", Times.Once(), ItExpr.IsAny<HttpRequestMessage>(), ItExpr.IsAny<CancellationToken>());
-				.Protected()
-				.Verify("SendAsync", Times.Once(), ItExpr.IsAny<HttpRequestMessage>(), ItExpr.IsAny<CancellationToken>());
 
 			_clientOptionsMock.VerifyGet(o => o.DefaultQueryParams, Times.Once);
 			VerifyNoOtherCalls();
@@ -167,6 +175,36 @@ namespace LinkMobility.Tests.Sms
 			VerifyNoOtherCalls();
 		}
 
+		[TestMethod]
+		public void ShouldThrowOnNullMessageContentList()
+		{
+			// Arrange
+			_request.MessageContent = null;
+			var client = GetClient();
+
+			// Act & Assert
+			var ex = Assert.ThrowsExactly<ArgumentException>(() => client.SendBinaryMessage(_request, TestContext.CancellationToken));
+
+			Assert.AreEqual("MessageContent", ex.ParamName);
+
+			VerifyNoOtherCalls();
+		}
+
+		[TestMethod]
+		public void ShouldThrowOnEmptyMessageContentList()
+		{
+			// Arrange
+			_request.MessageContent = [];
+			var client = GetClient();
+
+			// Act & Assert
+			var ex = Assert.ThrowsExactly<ArgumentException>(() => client.SendBinaryMessage(_request, TestContext.CancellationToken));
+
+			Assert.AreEqual("MessageContent", ex.ParamName);
+
+			VerifyNoOtherCalls();
+		}
+
 		[TestMethod]
 		public void ShouldThrowOnInvalidMessageEncoding()
 		{
@@ -205,7 +243,7 @@ namespace LinkMobility.Tests.Sms
 			// Act & Assert
 			var ex = Assert.ThrowsExactly<ArgumentException>(() => client.SendBinaryMessage(_request, TestContext.CancellationToken));
 
-			Assert.AreEqual("RecipientAddressList", ex.ParamName);
+			Assert.AreEqual("recipientAddressList", ex.ParamName);
 
 			VerifyNoOtherCalls();
 		}
@@ -224,7 +262,7 @@ namespace LinkMobility.Tests.Sms
 			// Act & Assert
 			var ex = Assert.ThrowsExactly<ArgumentException>(() => client.SendBinaryMessage(_request, TestContext.CancellationToken));
 
-			Assert.AreEqual("RecipientAddressList", ex.ParamName);
+			Assert.AreEqual("recipientAddressList", ex.ParamName);
 			Assert.StartsWith($"Recipient address '{recipient}' is not a valid MSISDN format.", ex.Message);
 
 			VerifyNoOtherCalls();

test/LinkMobility.Tests/Sms/SendTextMessageTest.cs

@@ -85,14 +85,27 @@ namespace LinkMobility.Tests.Sms
 			Assert.AreEqual("Scheme Parameter", callback.Headers["Authorization"]);
 			Assert.AreEqual("LinkMobilityClient/1.0.0", callback.Headers["User-Agent"]);
 
-			_httpMessageHandlerMock.Mock
+			_httpMessageHandlerMock.Protected.Verify("SendAsync", Times.Once(), ItExpr.IsAny<HttpRequestMessage>(), ItExpr.IsAny<CancellationToken>());
-				.Protected()
-				.Verify("SendAsync", Times.Once(), ItExpr.IsAny<HttpRequestMessage>(), ItExpr.IsAny<CancellationToken>());
 
 			_clientOptionsMock.VerifyGet(o => o.DefaultQueryParams, Times.Once);
 			VerifyNoOtherCalls();
 		}
 
+		[TestMethod]
+		public void ShouldThrowOnInvalidContentCategory()
+		{
+			// Arrange
+			_request.ContentCategory = 0;
+			var client = GetClient();
+
+			// Act & Assert
+			var ex = Assert.ThrowsExactly<ArgumentException>(() => client.SendTextMessage(_request, TestContext.CancellationToken));
+			Assert.AreEqual("contentCategory", ex.ParamName);
+			Assert.StartsWith("Content category '0' is not valid.", ex.Message);
+
+			VerifyNoOtherCalls();
+		}
+
 		[TestMethod]
 		public async Task ShouldSendTextMessageFullDetails()
 		{
@@ -145,9 +158,7 @@ namespace LinkMobility.Tests.Sms
 			Assert.AreEqual("Scheme Parameter", callback.Headers["Authorization"]);
 			Assert.AreEqual("LinkMobilityClient/1.0.0", callback.Headers["User-Agent"]);
 
-			_httpMessageHandlerMock.Mock
+			_httpMessageHandlerMock.Protected.Verify("SendAsync", Times.Once(), ItExpr.IsAny<HttpRequestMessage>(), ItExpr.IsAny<CancellationToken>());
-				.Protected()
-				.Verify("SendAsync", Times.Once(), ItExpr.IsAny<HttpRequestMessage>(), ItExpr.IsAny<CancellationToken>());
 
 			_clientOptionsMock.VerifyGet(o => o.DefaultQueryParams, Times.Once);
 			VerifyNoOtherCalls();
@@ -192,7 +203,7 @@ namespace LinkMobility.Tests.Sms
 
 			// Act & Assert
 			var ex = Assert.ThrowsExactly<ArgumentException>(() => client.SendTextMessage(req, TestContext.CancellationToken));
-			Assert.AreEqual("RecipientAddressList", ex.ParamName);
+			Assert.AreEqual("recipientAddressList", ex.ParamName);
 
 			VerifyNoOtherCalls();
 		}
@@ -211,7 +222,7 @@ namespace LinkMobility.Tests.Sms
 			// Act & Assert
 			var ex = Assert.ThrowsExactly<ArgumentException>(() => client.SendTextMessage(req, TestContext.CancellationToken));
 
-			Assert.AreEqual("RecipientAddressList", ex.ParamName);
+			Assert.AreEqual("recipientAddressList", ex.ParamName);
 			Assert.StartsWith($"Recipient address '{recipient}' is not a valid MSISDN format.", ex.Message);
 
 			VerifyNoOtherCalls();

test/LinkMobility.Tests/Utils/ValidationTest.cs

@@ -0,0 +1,33 @@
+using AMWD.Net.Api.LinkMobility.Utils;
+
+namespace LinkMobility.Tests.Utils
+{
+	[TestClass]
+	public class ValidationTest
+	{
+		[TestMethod]
+		[DataRow("10000000")]
+		[DataRow("12345678")]
+		[DataRow("123456789012345")]
+		[DataRow("14155552671")]
+		public void ShouldValidateMSISDNSuccessful(string msisdn)
+		{
+			Assert.IsTrue(Validation.IsValidMSISDN(msisdn));
+		}
+
+		[TestMethod]
+		[DataRow(null)]
+		[DataRow("")]
+		[DataRow(" ")]
+		[DataRow("012345678")]
+		[DataRow("+123456789")]
+		[DataRow("1234 5678")]
+		[DataRow("1234567")]
+		[DataRow("1234567890123456")]
+		[DataRow("abc1234567")]
+		public void ShouldValidateMSISDNNotSuccessful(string msisdn)
+		{
+			Assert.IsFalse(Validation.IsValidMSISDN(msisdn));
+		}
+	}
+}