From 590e37e2e19583468b8a2e890449ee418d1d1d29 Mon Sep 17 00:00:00 2001
From: AndyHeap-NeoTech <andrew.heap@neo4j.com>
Date: Thu, 2 Oct 2025 14:50:33 +0100
Subject: [PATCH 1/2] Fix for incorrect reporting of a type mismatch when
 object mapping fails and a Vector type is involved. Before the fix the error
 reported when trying to map from, for example, a Vector<float> to a
 Vector<double> was: System.InvalidOperationException: The expected value
 `Neo4j.Driver.Vector`1[System.Single]` is different from the actual value
 `System.Collections.Generic.List`1[System.Single]`

This was occurring because the ValueExtensions As method did not contain a clause for IVector, this caused the logic to fall through to the IEnumerable clause (which a vector implements) which converted the vector into a list, and then failed the type conversion on that list.

Now that a clause for IVector is added you get the correct error. e.g. For the Vector<float> -> Vector<double> example:
System.InvalidOperationException: The expected value `Neo4j.Driver.Vector`1[System.Single]` is different from the actual value `Neo4j.Driver.Vector`1[System.Double]`
---
 .../Neo4j.Driver/Public/Extensions/ValueExtensions.cs        | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/Neo4j.Driver/Neo4j.Driver/Public/Extensions/ValueExtensions.cs b/Neo4j.Driver/Neo4j.Driver/Public/Extensions/ValueExtensions.cs
index b24a4b825..5e02e00c9 100644
--- a/Neo4j.Driver/Neo4j.Driver/Public/Extensions/ValueExtensions.cs
+++ b/Neo4j.Driver/Neo4j.Driver/Public/Extensions/ValueExtensions.cs
@@ -149,6 +149,11 @@ public static T As<T>(this object value)
         {
             return Convert.ChangeType(value, targetType).AsItIs<T>();
         }
+        
+        if (value is IVector)
+        {
+            return value.AsItIs<T>();
+        }                 
 
         // force to cast to a dict or list
         var typeInfo = targetType.GetTypeInfo();

From 56902a79269bc1d90197e55635b75d0eae15bb47 Mon Sep 17 00:00:00 2001
From: AndyHeap-NeoTech <andrew.heap@neo4j.com>
Date: Thu, 16 Oct 2025 14:35:28 +0100
Subject: [PATCH 2/2] Added tests to check on vector conversions in the
 valueExtensions class. Vectors should not be able to be converted to any
 other type, or between mismatched vectors.

---
 .../ValueExtensionsTests.cs                   | 24 +++++++++++++++++++
 .../Public/Extensions/ValueExtensions.cs      | 17 +++++++++++--
 2 files changed, 39 insertions(+), 2 deletions(-)

diff --git a/Neo4j.Driver/Neo4j.Driver.Tests/ValueExtensionsTests.cs b/Neo4j.Driver/Neo4j.Driver.Tests/ValueExtensionsTests.cs
index 96c17b7db..f363dea0d 100644
--- a/Neo4j.Driver/Neo4j.Driver.Tests/ValueExtensionsTests.cs
+++ b/Neo4j.Driver/Neo4j.Driver.Tests/ValueExtensionsTests.cs
@@ -236,6 +236,30 @@ public void ShouldThrowExceptionWhenCastFromListToInt()
             var ex = Record.Exception(() => value.As<int>());
             ex.Should().BeOfType<InvalidCastException>();
         }
+
+        [Fact]
+        public void ShouldThrowExceptionWhenCastFromVectorToNonVector()
+        {
+            object value = new Vector<float>(new[] { 1.0f, 2.0f, 3.0f, 4.0f });
+            var ex = Record.Exception(() => value.As<int>());
+            ex.Should().BeOfType<InvalidCastException>();
+        }
+
+        [Fact]
+        public void ShouldThrowExceptionWhenCastFromNonVectorToVector()
+        {
+            object value = (int)10;
+            var ex = Record.Exception(() => value.As<Vector<int>>());
+            ex.Should().BeOfType<InvalidCastException>();
+        }
+
+        [Fact]
+        public void ShouldThrowExceptionWhenCastingBetweenMismatchedVectors()
+        {
+            object value = new Vector<float>(new[] { 1.0f, 2.0f, 3.0f, 4.0f });
+            var ex = Record.Exception(() => value.As<Vector<double>>());
+            ex.Should().BeOfType<InvalidCastException>();
+        }
     }
 
     public class AsCollectionTypeMethod
diff --git a/Neo4j.Driver/Neo4j.Driver/Public/Extensions/ValueExtensions.cs b/Neo4j.Driver/Neo4j.Driver/Public/Extensions/ValueExtensions.cs
index 5e02e00c9..dba2181e2 100644
--- a/Neo4j.Driver/Neo4j.Driver/Public/Extensions/ValueExtensions.cs
+++ b/Neo4j.Driver/Neo4j.Driver/Public/Extensions/ValueExtensions.cs
@@ -150,10 +150,12 @@ public static T As<T>(this object value)
             return Convert.ChangeType(value, targetType).AsItIs<T>();
         }
         
+        //If the source type (value) is a vector then it can not be cast to anything else. We also want to 
+        //make sure that it is not attempting to cast into a vector of another type. 
         if (value is IVector)
         {
-            return value.AsItIs<T>();
-        }                 
+            return AsVector<T>(value);
+        }                
 
         // force to cast to a dict or list
         var typeInfo = targetType.GetTypeInfo();
@@ -202,6 +204,17 @@ private static T AsList<T>(this IEnumerable value, TypeInfo typeInfo)
         return list.AsItIs<T>();
     }
 
+    private static T AsVector<T>(this object value)
+    {   
+        if (value is T result)
+        {
+            return result;
+        }
+        
+        throw new InvalidCastException($"Cannot cast differing vector types. Attempting from `" +
+            $" { typeof(T) }` to `{value.GetType()}");
+    }
+
 #region Helper Methods
 
     private static object InvokeStatic(this MethodInfo method, params object[] parameters)