Adding GetFormAsync on HttpRequest to read form data

src/Microsoft.AspNet.Abstractions/HttpRequest.cs

@@ -1,6 +1,7 @@
 using System;
 using System.IO;
 using System.Threading;
+using System.Threading.Tasks;
 
 namespace Microsoft.AspNet.Abstractions
 {
@@ -58,6 +59,12 @@ namespace Microsoft.AspNet.Abstractions
         /// <returns>The query value collection parsed from owin.RequestQueryString.</returns>
         public abstract IReadableStringCollection Query { get; }
 
+        /// <summary>
+        /// Gets the query value collection form collection.
+        /// </summary>
+        /// <returns>The form collection parsed from the request body.</returns>
+        public abstract Task<IReadableStringCollection> GetFormAsync();
+
         /// <summary>
         /// Gets or set the owin.RequestProtocol.
         /// </summary>

src/Microsoft.AspNet.PipelineCore/DefaultCanHasForm.cs

@@ -0,0 +1,42 @@
+using System.IO;
+using System.Text;
+using System.Threading.Tasks;
+using Microsoft.AspNet.Abstractions;
+using Microsoft.AspNet.FeatureModel;
+using Microsoft.AspNet.HttpFeature;
+using Microsoft.AspNet.PipelineCore.Collections;
+using Microsoft.AspNet.PipelineCore.Infrastructure;
+
+namespace Microsoft.AspNet.PipelineCore
+{
+    public class DefaultCanHasForm : ICanHasForm
+    {
+        private readonly IFeatureCollection _features;
+        private readonly FeatureReference<IHttpRequestInformation> _request = FeatureReference<IHttpRequestInformation>.Default;
+        private Stream _bodyStream;
+        private IReadableStringCollection _form;
+
+        public DefaultCanHasForm(IFeatureCollection features)
+        {
+            _features = features;
+        }
+
+        public async Task<IReadableStringCollection> GetFormAsync()
+        {
+            var body = _request.Fetch(_features).Body;
+
+            if (_bodyStream == null || _bodyStream != body)
+            {
+                _bodyStream = body;
+                using (var streamReader = new StreamReader(body, Encoding.UTF8,
+                                                           detectEncodingFromByteOrderMarks: true,
+                                                           bufferSize: 1024, leaveOpen: true))
+                {
+                    string formQuery = await streamReader.ReadToEndAsync();
+                    _form = new ReadableStringCollection(ParsingHelpers.GetQuery(formQuery));
+                }
+            }
+            return _form;
+        }
+    }
+}

src/Microsoft.AspNet.PipelineCore/DefaultHttpRequest.cs

@@ -1,6 +1,7 @@
 using System;
 using System.IO;
 using System.Threading;
+using System.Threading.Tasks;
 using Microsoft.AspNet.Abstractions;
 using Microsoft.AspNet.FeatureModel;
 using Microsoft.AspNet.HttpFeature;
@@ -18,6 +19,7 @@ namespace Microsoft.AspNet.PipelineCore
         private FeatureReference<IHttpConnection> _connection = FeatureReference<IHttpConnection>.Default;
         private FeatureReference<IHttpTransportLayerSecurity> _transportLayerSecurity = FeatureReference<IHttpTransportLayerSecurity>.Default;
         private FeatureReference<ICanHasQuery> _canHasQuery = FeatureReference<ICanHasQuery>.Default;
+        private FeatureReference<ICanHasForm> _canHasForm = FeatureReference<ICanHasForm>.Default;
         private FeatureReference<ICanHasRequestCookies> _canHasCookies = FeatureReference<ICanHasRequestCookies>.Default;
 
         public DefaultHttpRequest(DefaultHttpContext context, IFeatureCollection features)
@@ -46,6 +48,11 @@ namespace Microsoft.AspNet.PipelineCore
             get { return _canHasQuery.Fetch(_features) ?? _canHasQuery.Update(_features, new DefaultCanHasQuery(_features)); }
         }
 
+        private ICanHasForm CanHasForm
+        {
+            get { return _canHasForm.Fetch(_features) ?? _canHasForm.Update(_features, new DefaultCanHasForm(_features)); }
+        }
+
         private ICanHasRequestCookies CanHasRequestCookies
         {
             get { return _canHasCookies.Fetch(_features) ?? _canHasCookies.Update(_features, new DefaultCanHasRequestCookies(_features)); }
@@ -112,6 +119,11 @@ namespace Microsoft.AspNet.PipelineCore
             get { return CanHasQuery.Query; }
         }
 
+        public override Task<IReadableStringCollection> GetFormAsync()
+        {
+            return CanHasForm.GetFormAsync();
+        }
+
         public override string Protocol
         {
             get { return HttpRequestInformation.Protocol; }

src/Microsoft.AspNet.PipelineCore/ICanHasForm.cs

@@ -0,0 +1,10 @@
+using System.Threading.Tasks;
+using Microsoft.AspNet.Abstractions;
+
+namespace Microsoft.AspNet.PipelineCore
+{
+    public interface ICanHasForm
+    {
+        Task<IReadableStringCollection> GetFormAsync();
+    }
+}

test/Microsoft.AspNet.PipelineCore.Tests/DefaultCanHasFormTests.cs

@@ -0,0 +1,68 @@
+using System.IO;
+using System.Text;
+using System.Threading.Tasks;
+using Microsoft.AspNet.FeatureModel;
+using Microsoft.AspNet.HttpFeature;
+using Moq;
+using Xunit;
+
+namespace Microsoft.AspNet.PipelineCore.Tests
+{
+    public class DefaultCanHasFormTests
+    {
+        [Fact]
+        public async Task GetFormAsync_ReturnsParsedFormCollection()
+        {
+            // Arrange
+            var formContent = Encoding.UTF8.GetBytes("foo=bar&baz=2");
+            var features = new Mock<IFeatureCollection>();
+            var request = new Mock<IHttpRequestInformation>();
+            request.SetupGet(r => r.Body).Returns(new MemoryStream(formContent));
+
+            object value = request.Object;
+            features.Setup(f => f.TryGetValue(typeof(IHttpRequestInformation), out value))
+                    .Returns(true);
+
+            var provider = new DefaultCanHasForm(features.Object);
+
+            // Act
+            var formCollection = await provider.GetFormAsync();
+
+            // Assert
+            Assert.Equal("bar", formCollection["foo"]);
+            Assert.Equal("2", formCollection["baz"]);
+        }
+
+        [Fact]
+        public async Task GetFormAsync_CachesFormCollectionPerBodyStream()
+        {
+            // Arrange
+            var formContent1 = Encoding.UTF8.GetBytes("foo=bar&baz=2");
+            var formContent2 = Encoding.UTF8.GetBytes("collection2=value");
+            var features = new Mock<IFeatureCollection>();
+            var request = new Mock<IHttpRequestInformation>();
+            request.SetupGet(r => r.Body).Returns(new MemoryStream(formContent1));
+
+            object value = request.Object;
+            features.Setup(f => f.TryGetValue(typeof(IHttpRequestInformation), out value))
+                    .Returns(true);
+
+            var provider = new DefaultCanHasForm(features.Object);
+
+            // Act - 1
+            var formCollection = await provider.GetFormAsync();
+
+            // Assert - 1
+            Assert.Equal("bar", formCollection["foo"]);
+            Assert.Equal("2", formCollection["baz"]);
+            Assert.Same(formCollection, await provider.GetFormAsync());
+
+            // Act - 2
+            request.SetupGet(r => r.Body).Returns(new MemoryStream(formContent2));
+            formCollection = await provider.GetFormAsync();
+
+            // Assert - 2
+            Assert.Equal("value", formCollection["collection2"]);
+        }
+    }
+}