Logging made optional in TestMemoryAllocator

tests/ImageSharp.Tests/Memory/DiscontiguousBuffers/MemoryGroupTests.Allocate.cs

@@ -194,6 +194,7 @@ namespace SixLabors.ImageSharp.Tests.Memory.DiscontiguousBuffers
             public void MemoryAllocatorIsUtilizedCorrectly(AllocationOptions allocationOptions)
             {
                 this.MemoryAllocator.BufferCapacityInBytes = 200;
+                this.MemoryAllocator.EnableLogging();
 
                 HashSet<int> bufferHashes;
 

tests/ImageSharp.Tests/Processing/Processors/Transforms/ResizeTests.cs

@@ -117,6 +117,7 @@ namespace SixLabors.ImageSharp.Tests.Processing.Processors.Transforms
 
                 int workingBufferSizeHintInBytes = workingBufferLimitInRows * destSize.Width * SizeOfVector4;
                 var allocator = new TestMemoryAllocator();
+                allocator.EnableLogging();
                 configuration.MemoryAllocator = allocator;
                 configuration.WorkingBufferSizeHintInBytes = workingBufferSizeHintInBytes;
 

tests/ImageSharp.Tests/TestUtilities/TestMemoryAllocator.cs

@@ -12,8 +12,8 @@ namespace SixLabors.ImageSharp.Tests.Memory
 {
     internal class TestMemoryAllocator : MemoryAllocator
     {
-        private readonly List<AllocationRequest> allocationLog = new List<AllocationRequest>();
+        private List<AllocationRequest> allocationLog;
-        private readonly List<ReturnRequest> returnLog = new List<ReturnRequest>();
+        private List<ReturnRequest> returnLog;
 
         public TestMemoryAllocator(byte dirtyValue = 42)
         {
@@ -27,12 +27,18 @@ namespace SixLabors.ImageSharp.Tests.Memory
 
         public int BufferCapacityInBytes { get; set; } = int.MaxValue;
 
-        public IReadOnlyList<AllocationRequest> AllocationLog => this.allocationLog;
+        public IReadOnlyList<AllocationRequest> AllocationLog => this.allocationLog ?? throw new InvalidOperationException("Call TestMemoryAllocator.EnableLogging() first!");
 
-        public IReadOnlyList<ReturnRequest> ReturnLog => this.returnLog;
+        public IReadOnlyList<ReturnRequest> ReturnLog => this.returnLog ?? throw new InvalidOperationException("Call TestMemoryAllocator.EnableLogging() first!");
 
         protected internal override int GetBufferCapacityInBytes() => this.BufferCapacityInBytes;
 
+        public void EnableLogging()
+        {
+            this.allocationLog = new List<AllocationRequest>();
+            this.returnLog = new List<ReturnRequest>();
+        }
+
         public override IMemoryOwner<T> Allocate<T>(int length, AllocationOptions options = AllocationOptions.None)
         {
             T[] array = this.AllocateArray<T>(length, options);
@@ -43,7 +49,7 @@ namespace SixLabors.ImageSharp.Tests.Memory
             where T : struct
         {
             var array = new T[length + 42];
-            this.allocationLog.Add(AllocationRequest.Create<T>(options, length, array));
+            this.allocationLog?.Add(AllocationRequest.Create<T>(options, length, array));
 
             if (options == AllocationOptions.None)
             {
@@ -57,7 +63,7 @@ namespace SixLabors.ImageSharp.Tests.Memory
         private void Return<T>(BasicArrayBuffer<T> buffer)
             where T : struct
         {
-            this.returnLog.Add(new ReturnRequest(buffer.Array.GetHashCode()));
+            this.returnLog?.Add(new ReturnRequest(buffer.Array.GetHashCode()));
         }
 
         public struct AllocationRequest