changes callbacks to return ValueTask and adds Async suffix

initializes unused callbacks to null instead of noop since we're null-checking anyway

Author: wagich

src/ImageSharp.Web/Middleware/ImageContext.cs

@@ -125,9 +125,9 @@ public void ComprehendRequestHeaders(DateTimeOffset lastModified, long length)
         /// <param name="statusCode">The status code.</param>
         /// <param name="metaData">The image metadata.</param>
         /// <returns>The <see cref="Task"/>.</returns>
-        public async Task SendStatusAsync(int statusCode, ImageCacheMetadata metaData)
+        public Task SendStatusAsync(int statusCode, ImageCacheMetadata metaData)
         {
-            await this.ApplyResponseHeadersAsync(statusCode, metaData.ContentType, this.ComputeMaxAge(metaData));
+            return this.ApplyResponseHeadersAsync(statusCode, metaData.ContentType, this.ComputeMaxAge(metaData));
 
             // this.logger.LogHandled(statusCode, SubPath);
         }
@@ -192,9 +192,9 @@ private async Task ApplyResponseHeadersAsync(int statusCode, string contentType,
                     MustRevalidate = true
                 };
 
-                if (this.options.OnPrepareResponse != null)
+                if (this.options.OnPrepareResponseAsync != null)
                 {
-                    await this.options.OnPrepareResponse.Invoke(this.context);
+                    await this.options.OnPrepareResponseAsync.Invoke(this.context);
                 }
             }
 

src/ImageSharp.Web/Middleware/ImageSharpMiddleware.cs

@@ -167,9 +167,9 @@ public async Task Invoke(HttpContext context)
                 }
             }
 
-            if (this.options.OnParseCommands != null)
+            if (this.options.OnParseCommandsAsync != null)
             {
-                await this.options.OnParseCommands.Invoke(new ImageCommandContext(context, commands, CommandParser.Instance));
+                await this.options.OnParseCommandsAsync.Invoke(new ImageCommandContext(context, commands, CommandParser.Instance));
             }
 
             // Get the correct service for the request.
@@ -276,9 +276,9 @@ private async Task ProcessRequestAsync(HttpContext context, bool processRequest,
                                     using (var image = FormattedImage.Load(this.options.Configuration, inStream))
                                     {
                                         image.Process(this.logger, this.processors, commands);
-                                        if (this.options.OnBeforeSave != null)
+                                        if (this.options.OnBeforeSaveAsync != null)
                                         {
-                                            await this.options.OnBeforeSave.Invoke(image);
+                                            await this.options.OnBeforeSaveAsync.Invoke(image);
                                         }
 
                                         image.Save(outStream);
@@ -305,9 +305,9 @@ private async Task ProcessRequestAsync(HttpContext context, bool processRequest,
                             outStream.Position = 0;
                             string contentType = cachedImageMetadata.ContentType;
                             string extension = this.formatUtilities.GetExtensionFromContentType(contentType);
-                            if (this.options.OnProcessed != null)
+                            if (this.options.OnProcessedAsync != null)
                             {
-                                await this.options.OnProcessed.Invoke(new ImageProcessingContext(context, outStream, commands, contentType, extension));
+                                await this.options.OnProcessedAsync.Invoke(new ImageProcessingContext(context, outStream, commands, contentType, extension));
                             }
 
                             outStream.Position = 0;

src/ImageSharp.Web/Middleware/ImageSharpMiddlewareOptions.cs

@@ -39,7 +39,7 @@ public class ImageSharpMiddlewareOptions
         /// Gets or sets the additional command parsing method that can be used to used to augment commands.
         /// This is called once the commands have been gathered and before an <see cref="IImageProvider"/> has been assigned.
         /// </summary>
-        public Func<ImageCommandContext, Task> OnParseCommands { get; set; } = c =>
+        public Func<ImageCommandContext, ValueTask> OnParseCommandsAsync { get; set; } = c =>
         {
             if (c.Commands.Count != 0)
             {
@@ -55,28 +55,28 @@ public class ImageSharpMiddlewareOptions
                 }
             }
 
-            return Task.CompletedTask;
+            return default;
         };
 
         /// <summary>
         /// Gets or sets the additional method that can be used for final manipulation before the image is saved.
         /// This is called after image has been processed, but before the image has been saved to the output stream for caching.
         /// This can be used to alter the metadata of the resultant image.
         /// </summary>
-        public Func<FormattedImage, Task> OnBeforeSave { get; set; } = _ => Task.CompletedTask;
+        public Func<FormattedImage, ValueTask> OnBeforeSaveAsync { get; set; }
 
         /// <summary>
         /// Gets or sets the additional processing method.
         /// This is called after image has been processed, but before the result has been cached.
         /// This can be used to further optimize the resultant image.
         /// </summary>
-        public Func<ImageProcessingContext, Task> OnProcessed { get; set; } = _ => Task.CompletedTask;
+        public Func<ImageProcessingContext, ValueTask> OnProcessedAsync { get; set; }
 
         /// <summary>
         /// Gets or sets the additional response method.
         /// This is called after the status code and headers have been set, but before the body has been written.
         /// This can be used to add or change the response headers.
         /// </summary>
-        public Func<HttpContext, Task> OnPrepareResponse { get; set; } = _ => Task.CompletedTask;
+        public Func<HttpContext, ValueTask> OnPrepareResponseAsync { get; set; }
     }
 }

tests/ImageSharp.Web.Tests/ImageSharpTestServer.cs

@@ -43,10 +43,10 @@ public static class ImageSharpTestServer
                             options.MaxBrowserCacheDays = -1;
                             options.MaxCacheDays = -1;
                             options.CachedNameLength = 12;
-                            options.OnParseCommands = _ => Task.CompletedTask;
-                            options.OnBeforeSave = _ => Task.CompletedTask;
-                            options.OnProcessed = _ => Task.CompletedTask;
-                            options.OnPrepareResponse = _ => Task.CompletedTask;
+                            options.OnParseCommandsAsync = null;
+                            options.OnBeforeSaveAsync = null;
+                            options.OnProcessedAsync = null;
+                            options.OnPrepareResponseAsync = null;
                         })
                     .SetRequestParser<QueryCollectionRequestParser>()
                     .Configure<PhysicalFileSystemCacheOptions>(_ => { })
@@ -74,10 +74,10 @@ public static class ImageSharpTestServer
                         options.MaxBrowserCacheDays = -1;
                         options.MaxCacheDays = -1;
                         options.CachedNameLength = 12;
-                        options.OnParseCommands = _ => Task.CompletedTask;
-                        options.OnBeforeSave = _ => Task.CompletedTask;
-                        options.OnProcessed = _ => Task.CompletedTask;
-                        options.OnPrepareResponse = _ => Task.CompletedTask;
+                        options.OnParseCommandsAsync = null;
+                        options.OnBeforeSaveAsync = null;
+                        options.OnProcessedAsync = null;
+                        options.OnPrepareResponseAsync = null;
                     })
                     .SetRequestParser<QueryCollectionRequestParser>()
                     .Configure<PhysicalFileSystemCacheOptions>(_ => { })
@@ -112,10 +112,10 @@ void ConfigureServices(IServiceCollection services)
                     options.Configuration = Configuration.Default;
                     options.MaxBrowserCacheDays = -1;
                     options.MaxCacheDays = -1;
-                    options.OnParseCommands = onParseCommands;
-                    options.OnBeforeSave = onBeforeSave;
-                    options.OnProcessed = onProcessed;
-                    options.OnPrepareResponse = onPrepareResponse;
+                    options.OnParseCommandsAsync = null;
+                    options.OnBeforeSaveAsync = null;
+                    options.OnProcessedAsync = null;
+                    options.OnPrepareResponseAsync = null;
                 })
                 .SetRequestParser<QueryCollectionRequestParser>()
                 .Configure<PhysicalFileSystemCacheOptions>(_ => { })