Added email validation to CaptureFeedback methods

CHANGELOG.md

@@ -11,6 +11,7 @@
 
 - The HTTP instrumentation uses the span created for the outgoing request in the sentry-trace header, fixing the parent-child relationship between client and server ([#4264](https://github.com/getsentry/sentry-dotnet/pull/4264))
 - InvalidOperationException sending attachments on Android with LLVM enabled ([#4276](https://github.com/getsentry/sentry-dotnet/pull/4276))
+- When CaptureFeedback methods are called with invalid email addresses, a warning is now logged if Debug mode is enabled (explaining why the feedback has been dropped) ([#4284](https://github.com/getsentry/sentry-dotnet/pull/4284))
 
 ### Dependencies
 

src/Sentry/Internal/EmailValidator.cs

@@ -0,0 +1,41 @@
+using System.Text.RegularExpressions;
+
+namespace Sentry.Internal;
+
+/// <summary>
+/// Helper class for email validation.
+/// </summary>
+internal static partial class EmailValidator
+{
+    private const string EmailPattern = @"^[^@\s]+@[^@\s]+\.[^@\s]+$";
+
+#if NET9_0_OR_GREATER
+    [GeneratedRegex(EmailPattern)]
+    private static partial Regex EmailRegex { get; }
+#elif NET8_0
+    [GeneratedRegex(EmailPattern)]
+    private static partial Regex EmailRegex();
+    private static readonly Regex Email = EmailRegex();
+#else
+    private static readonly Regex Email = new(EmailPattern, RegexOptions.Compiled);
+#endif
+
+    /// <summary>
+    /// Validates an email address.
+    /// </summary>
+    /// <param name="email">The email address to validate.</param>
+    /// <returns>True if the email is valid, false otherwise.</returns>
+    public static bool IsValidEmail(string? email)
+    {
+        if (string.IsNullOrEmpty(email))
+        {
+            return true;
+        }
+
+#if NET9_0_OR_GREATER
+        return EmailRegex.IsMatch(email);
+#else
+        return Email.IsMatch(email);
+#endif
+    }
+}

src/Sentry/Internal/Hub.cs

@@ -553,6 +553,12 @@ public void CaptureFeedback(SentryFeedback feedback, Action<Scope> configureScop
 
         try
         {
+            if (!EmailValidator.IsValidEmail(feedback.ContactEmail))
+            {
+                _options.LogWarning("Feedback dropped due to invalid email format: '{0}'", feedback.ContactEmail);
+                return;
+            }
+
             var clonedScope = CurrentScope.Clone();
             configureScope(clonedScope);
 
@@ -573,6 +579,12 @@ public void CaptureFeedback(SentryFeedback feedback, Scope? scope = null, Sentry
 
         try
         {
+            if (!string.IsNullOrWhiteSpace(feedback.ContactEmail) && !EmailValidator.IsValidEmail(feedback.ContactEmail))
+            {
+                _options.LogWarning("Feedback dropped due to invalid email format: '{0}'", feedback.ContactEmail);
+                return;
+            }
+
             scope ??= CurrentScope;
             CurrentClient.CaptureFeedback(feedback, scope, hint);
         }
@@ -620,6 +632,12 @@ public void CaptureUserFeedback(UserFeedback userFeedback)
 
         try
         {
+            if (!string.IsNullOrWhiteSpace(userFeedback.Email) && !EmailValidator.IsValidEmail(userFeedback.Email))
+            {
+                _options.LogWarning("User feedback dropped due to invalid email format: '{0}'", userFeedback.Email);
+                return;
+            }
+
             CurrentClient.CaptureUserFeedback(userFeedback);
         }
         catch (Exception e)

test/Sentry.Tests/HubTests.cs

@@ -1,5 +1,6 @@
 using System.IO.Abstractions.TestingHelpers;
 using Sentry.Internal.Http;
+using Sentry.Protocol;
 using Sentry.Tests.Internals;
 
 namespace Sentry.Tests;
@@ -1742,7 +1743,7 @@ public void CaptureUserFeedback_HubEnabled(bool enabled)
             hub.Dispose();
         }
 
-        var feedback = new UserFeedback(SentryId.Create(), "foo", "bar", "baz");
+        var feedback = new UserFeedback(SentryId.Create(), "foo", "bar@example.com", "baz");
 
         // Act
         hub.CaptureUserFeedback(feedback);
@@ -1890,6 +1891,102 @@ await transport.Received(1)
     }
 
     private static Scope GetCurrentScope(Hub hub) => hub.ScopeManager.GetCurrent().Key;
+
+    [Theory]
+    [InlineData(null)]
+    [InlineData("")]
+    [InlineData(" ")]
+    [InlineData("[email protected]")]
+    [InlineData("[email protected]")]
+    [InlineData("[email protected]")]
+    public void CaptureFeedback_ValidEmail_FeedbackRegistered(string email)
+    {
+        // Arrange
+        var hub = _fixture.GetSut();
+        var feedback = new SentryFeedback("Test feedback", email);
+
+        // Act
+        hub.CaptureFeedback(feedback);
+
+        // Assert
+        _fixture.Client.Received(1).CaptureFeedback(Arg.Any<SentryFeedback>(), Arg.Any<Scope>(), Arg.Any<SentryHint>());
+    }
+
+    [Theory]
+    [InlineData("invalid-email")]
+    [InlineData("missing@domain")]
+    [InlineData("@missing-local.com")]
+    [InlineData("spaces [email protected]")]
+    public void CaptureFeedback_InvalidEmail_FeedbackDropped(string email)
+    {
+        // Arrange
+        _fixture.Options.Debug = true;
+        _fixture.Options.DiagnosticLogger = Substitute.For<IDiagnosticLogger>();
+        _fixture.Options.DiagnosticLogger!.IsEnabled(Arg.Any<SentryLevel>()).Returns(true);
+        var hub = _fixture.GetSut();
+        var feedback = new SentryFeedback("Test feedback", email);
+
+        // Act
+        hub.CaptureFeedback(feedback);
+
+        // Assert
+        _fixture.Client.DidNotReceive().CaptureFeedback(Arg.Any<SentryFeedback>(), Arg.Any<Scope>(), Arg.Any<SentryHint>());
+        _fixture.Options.DiagnosticLogger.Received(1).Log(
+            SentryLevel.Warning,
+            Arg.Is<string>(s => s.Contains("invalid email format")),
+            null,
+            Arg.Any<object[]>());
+    }
+
+    [Theory]
+    [InlineData(null)]
+    [InlineData("")]
+    [InlineData(" ")]
+    [InlineData("[email protected]")]
+    [InlineData("[email protected]")]
+    [InlineData("[email protected]")]
+    public void CaptureUserFeedback_ValidEmail_FeedbackRegistered(string email)
+    {
+#pragma warning disable CS0618 // Type or member is obsolete
+        // Arrange
+        var hub = _fixture.GetSut();
+        var feedback = new UserFeedback(SentryId.Create(), "Test name", email, "Test comment");
+
+        // Act
+        hub.CaptureUserFeedback(feedback);
+
+        // Assert
+        _fixture.Client.Received(1).CaptureUserFeedback(Arg.Any<UserFeedback>());
+#pragma warning restore CS0618 // Type or member is obsolete
+    }
+
+    [Theory]
+    [InlineData("invalid-email")]
+    [InlineData("missing@domain")]
+    [InlineData("@missing-local.com")]
+    [InlineData("spaces [email protected]")]
+    public void CaptureUserFeedback_InvalidEmail_FeedbackDropped(string email)
+    {
+#pragma warning disable CS0618 // Type or member is obsolete
+        // Arrange
+        _fixture.Options.Debug = true;
+        _fixture.Options.DiagnosticLogger = Substitute.For<IDiagnosticLogger>();
+        _fixture.Options.DiagnosticLogger!.IsEnabled(Arg.Any<SentryLevel>()).Returns(true);
+        var hub = _fixture.GetSut();
+        var feedback = new UserFeedback(SentryId.Create(), "Test name", email, "Test comment");
+
+        // Act
+        hub.CaptureUserFeedback(feedback);
+
+        // Assert
+        _fixture.Client.DidNotReceive().CaptureUserFeedback(Arg.Any<UserFeedback>());
+        _fixture.Options.DiagnosticLogger.Received(1).Log(
+            SentryLevel.Warning,
+            Arg.Is<string>(s => s.Contains("invalid email format")),
+            null,
+            Arg.Any<object[]>());
+#pragma warning restore CS0618 // Type or member is obsolete
+    }
 }
 
 #if NET6_0_OR_GREATER