Add type checking in contexts try get value (#1700)

Author: SimonCropp

CHANGELOG.md

@@ -9,6 +9,7 @@
   - NOTE: This can affect grouping. You can keep the original behavior by setting the option `KeepAggregateException` to `true`.
 - Serialize stack frame addresses as strings. ([#1692](https://github.com/getsentry/sentry-dotnet/pull/1692))
 - Improve serialization perf and fix memory leak in `SentryEvent` ([#1693](https://github.com/getsentry/sentry-dotnet/pull/1693))
+- Add type checking in contexts TryGetValue ([#1700](https://github.com/getsentry/sentry-dotnet/pull/1700))
 
 ### Features
 

src/Sentry/Internal/Extensions/CollectionsExtensions.cs

@@ -10,7 +10,16 @@ public static TValue GetOrCreate<TValue>(
             this ConcurrentDictionary<string, object> dictionary,
             string key)
             where TValue : class, new()
-            => (TValue)dictionary.GetOrAdd(key, _ => new TValue());
+        {
+            var value = dictionary.GetOrAdd(key, _ => new TValue());
+
+            if (value is TValue casted)
+            {
+                return casted;
+            }
+
+            throw new($"Expected a type of {typeof(TValue)} to exist for the key '{key}'. Instead found a {value.GetType()}. The likely cause of this is that the value for '{key}' has been incorrectly set to an instance of a different type.");
+        }
 
         public static void TryCopyTo<TKey, TValue>(this IDictionary<TKey, TValue> from, IDictionary<TKey, TValue> to)
             where TKey : notnull

test/Sentry.Tests/Internals/CollectionExtensionsTests.GetOrCreate_invalid_type.verified.txt

@@ -0,0 +1,4 @@
+{
+  Type: Exception,
+  Message: Expected a type of CollectionExtensionsTests+Value to exist for the key 'key'. Instead found a System.Int32. The likely cause of this is that the value for 'key' has been incorrectly set to an instance of a different type.
+}

test/Sentry.Tests/Internals/CollectionExtensionsTests.cs

@@ -0,0 +1,16 @@
+using System.Collections.Concurrent;
+
+[UsesVerify]
+public class CollectionExtensionsTests
+{
+    [Fact]
+    public Task GetOrCreate_invalid_type()
+    {
+        var dictionary = new ConcurrentDictionary<string, object> {["key"] = 1};
+        return Throws(() => dictionary.GetOrCreate<Value>("key")).IgnoreStackTrack();
+    }
+
+    class Value
+    {
+    }
+}