Fix and test for issue #418

Dapper.Contrib/SqlMapperExtensions.cs

@@ -368,7 +368,7 @@ private static string GetTableName(Type type)
             if (type.IsArray || type.IsGenericType())
                 type = type.GetGenericArguments()[0];
 
-            var keyProperties = KeyPropertiesCache(type);
+            var keyProperties = KeyPropertiesCache(type).ToList();  //added ToList() due to issue #418, must work on a list copy
             var explicitKeyProperties = ExplicitKeyPropertiesCache(type);
             if (!keyProperties.Any() && !explicitKeyProperties.Any())
                 throw new ArgumentException("Entity must have at least one [Key] or [ExplicitKey] property");
@@ -423,7 +423,7 @@ private static string GetTableName(Type type)
             if (type.IsArray || type.IsGenericType())
                 type = type.GetGenericArguments()[0];
 
-            var keyProperties = KeyPropertiesCache(type);
+            var keyProperties = KeyPropertiesCache(type).ToList();  //added ToList() due to issue #418, must work on a list copy
             var explicitKeyProperties = ExplicitKeyPropertiesCache(type);
             if (!keyProperties.Any() && !explicitKeyProperties.Any())
                 throw new ArgumentException("Entity must have at least one [Key] or [ExplicitKey] property");

Dapper.Tests.Contrib/TestSuite.cs

@@ -101,6 +101,35 @@ private IDbConnection GetOpenConnection()
             return connection;
         }
 
+        [Fact]
+        public void Issue418()
+        {
+            using (var connection = GetOpenConnection())
+            {
+                //update first (will fail) then insert
+                //added for bug #418
+                var updateObject = new ObjectX()
+                {
+                    ObjectXId = Guid.NewGuid().ToString(),
+                    Name = "Someone"
+                };
+                var updates = connection.Update(updateObject);
+                updates.IsFalse();
+
+                connection.DeleteAll<ObjectX>();
+
+                var objectXId = Guid.NewGuid().ToString();
+                var insertObject = new ObjectX()
+                {
+                    ObjectXId = objectXId,
+                    Name = "Someone else"
+                };
+                var inserts = connection.Insert(insertObject);
+                var list = connection.GetAll<ObjectX>();
+                list.Count().IsEqualTo(1);
+            }
+        }
+
         /// <summary>
         /// Tests for issue #351 
         /// </summary>