Ignore null value on CocoaScopeObserver.SetTag (#3948)

Author: Cheesebaron

CHANGELOG.md

@@ -9,6 +9,7 @@
 - Fixed envelopes with oversized attachments getting stuck in __processing ([#3938](https://github.com/getsentry/sentry-dotnet/pull/3938))
 - Unknown stack frames in profiles on .NET 8+ ([#3942](https://github.com/getsentry/sentry-dotnet/pull/3942))
 - Deduplicate profiling stack frames ([#3941](https://github.com/getsentry/sentry-dotnet/pull/3941))
+- Ignore null value on CocoaScopeObserver.SetTag ([#3948](https://github.com/getsentry/sentry-dotnet/pull/3948))
 
 ## 5.1.0
 

src/Sentry/Platforms/Cocoa/CocoaScopeObserver.cs

@@ -67,6 +67,12 @@ public void SetExtra(string key, object? value)
 
     public void SetTag(string key, string value)
     {
+        if (value is null)
+        {
+            _options.LogDebug("Tag with key '{0}' was null. Use Unset to remove tags instead.", key);
+            return;
+        }
+
         try
         {
             SentryCocoaSdk.ConfigureScope(scope => scope.SetTagValue(value, key));

test/Sentry.Tests/ScopeTests.cs

@@ -615,6 +615,24 @@ public void Filtered_tags_are_not_set()
 
         scope.Tags.Should().OnlyContain(pair => pair.Key == "AzFunctions" && pair.Value == "rule");
     }
+
+    [Fact]
+    public void SetTag_NullValue_DoesNotThrowArgumentNullException()
+    {
+        var scope = new Scope();
+
+        ArgumentNullException exception = null;
+        try
+        {
+            scope.SetTag("IAmNull", null);
+        }
+        catch (ArgumentNullException e)
+        {
+            exception = e;
+        }
+
+        Assert.Null(exception);
+    }
 }
 
 public static class ScopeTestExtensions