ShouldThrowValidationExceptionIfNoReceiverWasAdded -> FAIL

FlexiMail.Tests.Unit/Services/FlexiExchangeServiceTests.Validations.cs

@@ -55,5 +55,66 @@ await Assert.ThrowsAsync<FlexiMessageValidationException>(
                     broker.SendAndSaveCopy(It.IsAny<EmailMessage>()),
                 Times.Never);
         }
+
+        [Fact]
+        public async void ShouldThrowValidationExceptionIfNoReceiverWasAdded()
+        {
+            // given 
+            var randomFlexiMessage = CreateRandomFlexiMessage();
+
+            randomFlexiMessage.To = null;
+            randomFlexiMessage.Cc = null;
+            randomFlexiMessage.Bcc = null;
+
+            var inputFlexiMessage = randomFlexiMessage;
+
+            var invalidFlexiMessageException =
+                new InvalidFlexiMessageException(
+                    message: "FlexiMessage has no receiver.");
+
+            invalidFlexiMessageException.AddData(
+                key: nameof(FlexiMessage.To),
+                values: "To is not set.");
+
+            invalidFlexiMessageException.AddData(
+                key: nameof(FlexiMessage.Cc),
+                values: "Cc is not set.");
+
+            invalidFlexiMessageException.AddData(
+                key: nameof(FlexiMessage.Bcc),
+                values: "Bcc is not set.");
+
+            var expectedFlexiMessageValidationException =
+                new FlexiMessageValidationException(
+                    message: "Flexi Message validation error occurred, fix errors and try again.",
+                    innerException: invalidFlexiMessageException);
+
+            // when
+            var sendMessageTask =
+                this.flexiExchangeService.SendAndSaveCopyAsync(inputFlexiMessage);
+
+            var actualFlexiMessageValidationException =
+                await Assert.ThrowsAsync<FlexiMessageValidationException>(
+                    sendMessageTask.AsTask);
+            // then
+
+            actualFlexiMessageValidationException.Should()
+                .BeEquivalentTo(expectedFlexiMessageValidationException);
+
+            this.exchangeBrokerMock.Verify(broker =>
+                    broker.GetAccessTokenAsync(),
+                Times.Never);
+
+            this.exchangeBrokerMock.Verify(broker =>
+                    broker.CreateExchangeService(
+                        ExchangeVersion.Exchange2013,
+                        It.IsAny<string>(),
+                        It.IsAny<ImpersonatedUserId>()),
+                Times.Never);
+
+            this.exchangeBrokerMock.Verify(broker =>
+                    broker.SendAndSaveCopy(It.IsAny<EmailMessage>()),
+                Times.Never);
+        }
     }
 }

FlexiMail/Models/Foundations/Messages/Exceptions/InvalidFlexiMessageException.cs

@@ -0,0 +1,20 @@
+// ---------------------------------------
+// Copyright (c) 2024 Mabrouk Mahdhi.
+// Made with love for the .NET Community
+// ---------------------------------------
+
+using Xeptions;
+
+namespace FlexiMail.Models.Foundations.Messages.Exceptions
+{
+    public class InvalidFlexiMessageException : Xeption
+    {
+        public InvalidFlexiMessageException(string message)
+            : base(message)
+        { }
+
+        public InvalidFlexiMessageException(string message, Xeption innerException)
+            : base(message, innerException)
+        { }
+    }
+}

FlexiMail/Services/FlexiExchangeService.Validations.cs

@@ -13,6 +13,8 @@ internal partial class FlexiExchangeService
         private static void ValidFlexiMessage(FlexiMessage flexiMessage)
         {
             ValidFlexiMessageIsNotNull(flexiMessage);
+
+
         }
 
         private static void ValidFlexiMessageIsNotNull(FlexiMessage flexiMessage)