Add test extensions to easily deserialize responses (#505)

Modules/Conversion/Serializers/SerializationRegistry.cs

@@ -1,71 +1,81 @@
-using System.Collections.Generic;
-
-using GenHTTP.Api.Protocol;
-
-namespace GenHTTP.Modules.Conversion.Providers
-{
-
-    /// <summary>
-    /// Registers formats that can be used to serialize and
-    /// deserialize objects sent to or received from a 
-    /// service oriented handler.
-    /// </summary>
-    public sealed class SerializationRegistry
-    {
-
-        #region Get-/Setters
-
-        private FlexibleContentType Default { get; }
-
-        private Dictionary<FlexibleContentType, ISerializationFormat> Formats { get; }
-
-        #endregion
-
-        #region Initialization
-
-        public SerializationRegistry(FlexibleContentType defaultType,
-                                     Dictionary<FlexibleContentType, ISerializationFormat> formats)
-        {
-            Default = defaultType;
-            Formats = formats;
-        }
-
-        #endregion
-
-        #region Functionality
-
-        public ISerializationFormat? GetDeserialization(IRequest request)
-        {
-            if (request.Headers.TryGetValue("Content-Type", out string? requested))
-            {
-                return GetFormat(FlexibleContentType.Parse(requested));
-            }
-
-            return GetFormat(Default);
-        }
-
-        public ISerializationFormat? GetSerialization(IRequest request)
-        {
-            if (request.Headers.TryGetValue("Accept", out string? accepted))
-            {
-                return GetFormat(FlexibleContentType.Parse(accepted)) ?? GetFormat(Default);
-            }
-
-            return GetFormat(Default);
-        }
-
-        private ISerializationFormat? GetFormat(FlexibleContentType contentType)
-        {
-            if (Formats.TryGetValue(contentType, out var format))
-            {
-                return format;
-            }
-
-            return null;
-        }
-
-        #endregion
-
-    }
-
-}
+using System.Collections.Generic;
+
+using GenHTTP.Api.Protocol;
+
+namespace GenHTTP.Modules.Conversion.Providers
+{
+
+    /// <summary>
+    /// Registers formats that can be used to serialize and
+    /// deserialize objects sent to or received from a 
+    /// service oriented handler.
+    /// </summary>
+    public sealed class SerializationRegistry
+    {
+
+        #region Get-/Setters
+
+        private FlexibleContentType Default { get; }
+
+        private Dictionary<FlexibleContentType, ISerializationFormat> Formats { get; }
+
+        #endregion
+
+        #region Initialization
+
+        public SerializationRegistry(FlexibleContentType defaultType,
+                                     Dictionary<FlexibleContentType, ISerializationFormat> formats)
+        {
+            Default = defaultType;
+            Formats = formats;
+        }
+
+        #endregion
+
+        #region Functionality
+
+        public ISerializationFormat? GetDeserialization(IRequest request)
+        {
+            if (request.Headers.TryGetValue("Content-Type", out string? requested))
+            {
+                return GetFormat(FlexibleContentType.Parse(requested));
+            }
+
+            return GetFormat(Default);
+        }
+
+        public ISerializationFormat? GetSerialization(IRequest request)
+        {
+            if (request.Headers.TryGetValue("Accept", out string? accepted))
+            {
+                return GetFormat(FlexibleContentType.Parse(accepted)) ?? GetFormat(Default);
+            }
+
+            return GetFormat(Default);
+        }
+
+        public ISerializationFormat? GetFormat(string? contentType)
+        {
+            if (contentType != null)
+            {
+                return GetFormat(FlexibleContentType.Parse(contentType));
+            }
+
+            return GetFormat(Default);
+        }
+
+        private ISerializationFormat? GetFormat(FlexibleContentType contentType)
+        {
+            if (Formats.TryGetValue(contentType, out var format))
+            {
+                return format;
+            }
+
+            return null;
+        }
+
+        #endregion
+
+    }
+
+}

Testing/Acceptance/Testing/ContentTests.cs

@@ -0,0 +1,63 @@
+using System;
+using System.Threading.Tasks;
+using GenHTTP.Api.Protocol;
+using GenHTTP.Modules.Functional;
+using GenHTTP.Modules.Reflection;
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+
+namespace GenHTTP.Testing.Acceptance.Testing
+{
+
+    [TestClass]
+    public sealed class ContentTests
+    {
+
+        public record class MyType(int ID);
+
+        [TestMethod]
+        public async Task TestDeserialization()
+        {
+            var expectation = new MyType(42);
+
+            var handler = Inline.Create()
+                                .Get(() => expectation);
+
+            using var host = TestHost.Run(handler);
+
+            using var response = await host.GetResponseAsync();
+
+            Assert.AreEqual(expectation, await response.GetContentAsync<MyType>());
+        }
+
+        [TestMethod]
+        public async Task TestNull()
+        {
+            var handler = Inline.Create()
+                                .Get(() => (MyType?)null);
+
+            using var host = TestHost.Run(handler);
+
+            using var response = await host.GetResponseAsync();
+
+            Assert.IsNull(await response.GetOptionalContentAsync<MyType>());
+        }
+
+        [TestMethod]
+        public async Task TestUnsupported()
+        {
+            var handler = Inline.Create()
+                                .Get(() => new Result<string>("Nah").Type(FlexibleContentType.Get("text/html")));
+
+            using var host = TestHost.Run(handler);
+
+            using var response = await host.GetResponseAsync();
+
+            await Assert.ThrowsExceptionAsync<InvalidOperationException>(async () =>
+            {
+                await response.GetOptionalContentAsync<MyType>();
+            });
+        }
+
+    }
+
+}

Testing/Testing/ContentExtensions.cs

@@ -0,0 +1,71 @@
+using System;
+using System.Net;
+using System.Net.Http;
+using System.Threading.Tasks;
+
+using GenHTTP.Modules.Conversion;
+using GenHTTP.Modules.Protobuf;
+
+namespace GenHTTP.Testing
+{
+
+    public static class ContentExtensions
+    {
+
+        /// <summary>
+        /// Reads the response body as a string.
+        /// </summary>
+        /// <param name="response">The response to read</param>
+        /// <returns>The content of the HTTP response</returns>
+        public static async ValueTask<string> GetContentAsync(this HttpResponseMessage response) => await response.Content.ReadAsStringAsync();
+
+        /// <summary>
+        /// Deserializes the payload of the HTTP response into the given type.
+        /// </summary>
+        /// <typeparam name="T">The type of the payload to be read</typeparam>
+        /// <param name="response">The response to read the payload from</param>
+        /// <returns>The deserialized payload of the response</returns>
+        /// <exception cref="InvalidOperationException">Thrown if the format returned by the server is not supported</exception>
+        /// <remarks>
+        /// This method supports all formats that ship with the GenHTTP framework (JSON, XML, form encoded, Protobuf)
+        /// and falls back to JSON if the server does not indicate a content type.
+        /// </remarks>
+        public static async ValueTask<T> GetContentAsync<T>(this HttpResponseMessage response)
+        {
+            return await response.GetOptionalContentAsync<T>() ?? throw new InvalidOperationException("Server did not return a result");
+        }
+
+        /// <summary>
+        /// Attempts to deserialize the payload of the HTTP response into the given type.
+        /// </summary>
+        /// <typeparam name="T">The type of the payload to be read</typeparam>
+        /// <param name="response">The response to read the payload from</param>
+        /// <returns>The deserialized payload of the response or null, if the server did not return data</returns>
+        /// <exception cref="InvalidOperationException">Thrown if the format returned by the server is not supported</exception>
+        /// <remarks>
+        /// This method supports all formats that ship with the GenHTTP framework (JSON, XML, form encoded, Protobuf)
+        /// and falls back to JSON if the server does not indicate a content type.
+        /// </remarks>
+        public static async ValueTask<T?> GetOptionalContentAsync<T>(this HttpResponseMessage response)
+        {
+            if (response.StatusCode == HttpStatusCode.NoContent)
+            {
+                return default;
+            }
+
+            var type = response.GetContentHeader("Content-Type");
+
+            var registry = Serialization.Default()
+                                        .AddProtobuf()
+                                        .Build();
+
+            var format = registry.GetFormat(type) ?? throw new InvalidOperationException($"Unable to find deserializer for content type '{type}'");
+
+            using var body = await response.Content.ReadAsStreamAsync();
+
+            return (T?)await format.DeserializeAsync(body, typeof(T));
+        }
+
+    }
+
+}

Testing/Testing/GenHTTP.Testing.csproj

@@ -48,6 +48,8 @@
     <ProjectReference Include="..\..\Modules\Basics\GenHTTP.Modules.Basics.csproj" />
     <ProjectReference Include="..\..\Modules\Layouting\GenHTTP.Modules.Layouting.csproj" />
     <ProjectReference Include="..\..\Modules\Practices\GenHTTP.Modules.Practices.csproj" />
+	<ProjectReference Include="..\..\Modules\Conversion\GenHTTP.Modules.Conversion.csproj" />
+	<ProjectReference Include="..\..\Modules\Protobuf\GenHTTP.Modules.Protobuf.csproj" />
 
     <PackageReference Include="Microsoft.SourceLink.GitHub" Version="8.0.0" PrivateAssets="All" />
 

Testing/Testing/TestExtensions.cs → Testing/Testing/HeaderExtensions.cs

@@ -1,40 +1,32 @@
-using System.Linq;
-using System.Net.Http;
-using System.Threading.Tasks;
-
-namespace GenHTTP.Testing
-{
-
-    public static class TestExtensions
-    {
-
-        /// <summary>
-        /// Reads the response body as a string.
-        /// </summary>
-        /// <param name="response">The response to read</param>
-        /// <returns>The content of the HTTP response</returns>
-        public static async ValueTask<string> GetContentAsync(this HttpResponseMessage response) => await response.Content.ReadAsStringAsync();
-
-        public static string? GetHeader(this HttpResponseMessage response, string key)
-        {
-            if (response.Headers.TryGetValues(key, out var values))
-            {
-                return values.FirstOrDefault();
-            }
-
-            return null;
-        }
-
-        public static string? GetContentHeader(this HttpResponseMessage response, string key)
-        {
-            if (response.Content.Headers.TryGetValues(key, out var values))
-            {
-                return values.FirstOrDefault();
-            }
-
-            return null;
-        }
-
-    }
-
-}
+using System.Linq;
+using System.Net.Http;
+
+namespace GenHTTP.Testing
+{
+
+    public static class HeaderExtensions
+    {
+
+        public static string? GetHeader(this HttpResponseMessage response, string key)
+        {
+            if (response.Headers.TryGetValues(key, out var values))
+            {
+                return values.FirstOrDefault();
+            }
+
+            return null;
+        }
+
+        public static string? GetContentHeader(this HttpResponseMessage response, string key)
+        {
+            if (response.Content.Headers.TryGetValues(key, out var values))
+            {
+                return values.FirstOrDefault();
+            }
+
+            return null;
+        }
+
+    }
+
+}