Update to .NET Standard 2.1 & .NET Core 3.0

Author: TheCodeTraveler

.gitignore

@@ -6,22 +6,22 @@ namespace DotNetGraphQL.API
 {
     public static class DogImagesData
     {
-        readonly static Lazy<List<DogImagesModel>> _dogImagesHolder = new Lazy<List<DogImagesModel>>(CreateDogImageList);
+        readonly static Lazy<IEnumerable<DogImagesModel>> _dogImagesHolder = new Lazy<IEnumerable<DogImagesModel>>(CreateDogImageList);
 
-        public static List<DogImagesModel> DogImages => _dogImagesHolder.Value;
+        public static IEnumerable<DogImagesModel> DogImages => _dogImagesHolder.Value;
 
-        static List<DogImagesModel> CreateDogImageList() => new List<DogImagesModel>
+        static IEnumerable<DogImagesModel> CreateDogImageList()
         {
-            GenerateKirbyModel(),
-            GenerateWafflesModel(),
-            GenerateWhiskeyModel(),
-            GenerateTobyModel(),
-            GenerateMozzieModel(),
-            GenerateMiloModel(),
-            GeneratePiperModel(),
-            GenerateMagicModel(),
-            GenerateHermesModel()
-        };
+            yield return GenerateKirbyModel();
+            yield return GenerateWafflesModel();
+            yield return GenerateWhiskeyModel();
+            yield return GenerateTobyModel();
+            yield return GenerateMozzieModel();
+            yield return GenerateMiloModel();
+            yield return GeneratePiperModel();
+            yield return GenerateMagicModel();
+            yield return GenerateHermesModel();
+        }
 
         static DogImagesModel GenerateKirbyModel()
         {
@@ -57,7 +57,7 @@ static DogImagesModel GenerateWafflesModel()
                 "https://scontent-sjc3-1.cdninstagram.com/vp/463d2f790dad456aa7f907fbc5c4f2d5/5E5E4DA2/t51.2885-15/e35/p1080x1080/68904319_153662302373174_5867607915252717949_n.jpg?_nc_ht=scontent-sjc3-1.cdninstagram.com&_nc_cat=102",
                 "https://scontent-sjc3-1.cdninstagram.com/vp/6f094e68dcea3ce76025bc9a3aae1d10/5E4B5760/t51.2885-15/e35/p1080x1080/61615381_142948983481771_3906781618639463667_n.jpg?_nc_ht=scontent-sjc3-1.cdninstagram.com&_nc_cat=107",
                 "https://scontent-sjc3-1.cdninstagram.com/vp/df20cab484e3fdce8e7b93be068cd955/5E5F68F4/t51.2885-15/e35/p1080x1080/60983676_671182750019423_8627416967785409822_n.jpg?_nc_ht=scontent-sjc3-1.cdninstagram.com&_nc_cat=111",
-                "https://scontent-sjc3-1.cdninstagram.com/vp/4a5977fc6da543a3580dc65bec020f72/5E420BE3/t51.2885-15/e35/p1080x1080/60306434_315395119395230_9143171722741474046_n.jpg?_nc_ht=scontent-sjc3-1.cdninstagram.com&_nc_cat=102",
+                "https://scontent-sjc3-1.cdninstagram.com/vp/4a5977fc6da543a3580dc65bec020f72/5E420BE3/t51.2885-15/e35/p1080x1080/60306434_315395119395230_9143171722741474046_n.jpg?_nc_ht=scontent-sjc3-1.cdninstagram.com&_nc_cat=102"
             };
 
             var breed = "Australian Labradoodle";
@@ -69,7 +69,7 @@ static DogImagesModel GenerateWafflesModel()
 
         static DogImagesModel GenerateWhiskeyModel()
         {
-            var avatarUrl = "https://scontent-sjc3-1.cdninstagram.com/vp/dec8edaafd32ef4f16ce77c2b65eea32/5E62D3AA/t51.2885-19/s320x320/67436293_862189824165677_126933068328992768_n.jpg?_nc_ht=scontent-sjc3-1.cdninstagram.com";
+            var avatarUrl = "https://scontent-sjc3-1.cdninstagram.com/vp/d0cc41e4c2f2fad7e41ed5f9462421f4/5E6FDB22/t51.2885-19/s320x320/75487930_545788479570130_7341431923115294720_n.jpg?_nc_ht=scontent-sjc3-1.cdninstagram.com";
             var websiteUrl = "https://www.whiskeythegoldendoodle.com/";
             var name = "Whiskey";
 
@@ -173,7 +173,7 @@ static DogImagesModel GenerateMiloModel()
 
             return new DogImagesModel(avatarUrl, websiteUrl, name, photosList, breed, coatColor);
         }
-        
+
         static DogImagesModel GenerateMagicModel()
         {
             var avatarUrl = "https://lh3.googleusercontent.com/8B2KQsTtG1nraAD8oE6N2wjNbK-EFEiZMOd3aJkg_Dqf_Wf34MRXjbs8VDIn8w7DTTmz16BbhIQ7hfE-5Xkuruj1lPVgOcZxY3hpGbn483jpnrmW-WfAcC5jg1wsFZ02-Pt5x7tUGCDbl7BfrH0zdaBaxOk3uyOs_zUKHExpSRb125oV7IgBhI9WYuyxSPbZsQVlBCh_NP-yb3B34vZx1IE5D4uHkc960c5V00C_AEllgX5rjMBEyRW9KhDt7gfmvYcssP6VwOH_WtY9gpyNaYihYCubRPtJDX_XnS6mOLMaI3n6i2f8dTo6hJEuCAP-wpybOXCwvBIq0QcmJJUorCH8_Z1-bocfwIZjDNfxVoQ9DC2_N2ZlWAT7eBVRnGSlAXTO4gpFZ9Pj2RYgWqmj1I98_3NWMPKMvlR_-DTAAKX4bkptZ86vsx1Z1e_62l7e7f-3XD9Eg8i_6AZzSOTEOvifOY9mZe8I_VXiYriAOujsIs3sdKeCDNuoLU91cVK9ZdnqJG_ppUkkEGC3V_oMTkE2gXvej6Dvl1vBrVXyoyT9jYjJVUzLZVj4kE9oltojy11ssvUzUs0_RZv_MS1h0Yp645NbyeKdNtDRgyoBPTGhsJj8eMtO_ljjmwqjndwv3M7Wm3Vwl7xfJdSLSmyaAYYauieu3uYbXBPRizLg0jkeWJ8ZvjaKQ2UlD4UqQWAukAtrbcgtsKqPgYCAFU8o6HGXS8bx4JLcZY5BG_8SZhcYlWyP=w989-h742-no";
@@ -193,7 +193,7 @@ static DogImagesModel GenerateMagicModel()
 
             return new DogImagesModel(avatarUrl, websiteUrl, name, photosList, breed, coatColor, birthDate);
         }
-        
+
         static DogImagesModel GenerateHermesModel()
         {
             var avatarUrl = "https://lh3.googleusercontent.com/9kWTrt54igZZj2pEb0y7WVjvosu8PGmT2YFtLg9bTO_-U4NqKkdPZ2i15n2nRCWN-bmyOjFTC4sf0vtK7HqBxLzqzn1_JHn0nptex-GyA7KCfvI2Lli2i1Y5gMbrcaKU_dWTTFxPvcWZEKEiOfGkXYFk8DfWas3uvrGsjE2SQs2dRMndcSttu-SaUuNBDoQROq0IEgnpFx6MS0H5GxlZFCKyDll2CsJfBPYMp2iFBQbKcBNc45Z7UFJDyJx8DxuHT3JYUIabdCFqSKzPXt6ibnlGTs4GFsBA77RIKsivEF2kDT-HXoTGY9M4vxwzgt-6M9-UCjuL-QM_Rci0jyRh08WnpqlkF1MemXIu6kKc7pA-e0gOkVMsoODJ6E1d9Wl95v2bc4FrgJzibHrIyh7LoIKWgV9ImXRXd7i2ZVAiMekbJwRWQUDu9VgvMjBpSW1Qtn6T55_XvA1WZiYamZ33FbDyDzxzYNXwyOAap7U593CDY-b_h2_6IBhVX8tW0WRQgB2igzM7dXtWgIdf2wSfK-7UvWzX9bOfYplIVjXbzxWQF_VYjb6nItW9T7NFXNkx6aipdymb_Cgv-_jbSVfWLYESuMy490DIO_NIvSXqwcAz8r7NOTBvnSp0wYZugdH2v7KKT7v2KZ1_rFi7JTbMof4KFHkFlwQ23aI81VfDls4YRkrikyO1Uf6qUlzJXeOSrAi1BlZXrMcfZJyYmOCDfRUVofMxnTtUiB5Gi9oeswl8-4uX=w509-h382-no";

LICENSE

@@ -1,19 +1,14 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project Sdk="Microsoft.NET.Sdk.Web">
     <PropertyGroup>
-        <TargetFramework>netcoreapp2.2</TargetFramework>
-        <LangVersion>8.0</LangVersion>
+        <TargetFramework>netcoreapp3.0</TargetFramework>
         <Nullable>Enable</Nullable>
         <ProduceReferenceAssembly>True</ProduceReferenceAssembly>
     </PropertyGroup>
 
     <ItemGroup>
-        <PackageReference Include="GraphQL" Version="3.0.0-preview-1271" />
+        <PackageReference Include="GraphQL" Version="3.0.0-preview-1352" />
         <PackageReference Include="GraphQL.Common" Version="2.0.0-alpha.3" />
-        <PackageReference Include="Microsoft.AspNetCore.App">
-          <PrivateAssets Condition="'%(PackageReference.Version)' == ''">all</PrivateAssets>
-          <Publish Condition="'%(PackageReference.Version)' == ''">true</Publish>
-        </PackageReference>
     </ItemGroup>
     <ItemGroup>
         <ProjectReference Include="..\DotNetGraphQL.Common\DotNetGraphQL.Common.csproj">

README.md

@@ -1,4 +1,5 @@
 using System;
+using System.Diagnostics.CodeAnalysis;
 using System.IO;
 using System.Linq;
 using System.Net;
@@ -31,8 +32,10 @@ public GraphQLMiddleware(RequestDelegate next, GraphQLSettings settings, IDocume
 
         public Task Invoke(HttpContext context, ISchema schema)
         {
-            if (IsGraphQLRequest(context))
-                return ExecuteAsync(context, schema);
+            var (isGraphQLRequest, request) = IsGraphQLRequest(context);
+
+            if (isGraphQLRequest && request is GraphQLRequest)
+                return ExecuteAsync(context, schema, request);
 
             return _next(context);
         }
@@ -45,16 +48,21 @@ static T Deserialize<T>(Stream stream)
             return Serializer.Deserialize<T>(jsonTextReader);
         }
 
-        bool IsGraphQLRequest(HttpContext context)
+        (bool isGraphQLRequest, GraphQLRequest? request) IsGraphQLRequest(HttpContext context)
         {
-            return context.Request.Path.StartsWithSegments(_settings.Path)
-                && context.Request.Method.Equals("POST", StringComparison.OrdinalIgnoreCase);
+            try
+            {
+                return (context.Request.Path.StartsWithSegments(_settings.Path) && context.Request.Method.Equals("POST", StringComparison.OrdinalIgnoreCase),
+                            Deserialize<GraphQLRequest>(context.Request.Body));
+            }
+            catch
+            {
+                return (false, null);
+            }
         }
 
-        async Task ExecuteAsync(HttpContext context, ISchema schema)
+        async Task ExecuteAsync(HttpContext context, ISchema schema, GraphQLRequest request)
         {
-            var request = Deserialize<GraphQLRequest>(context.Request.Body);
-
             var result = await _executer.ExecuteAsync(options =>
             {
                 options.Schema = schema;

Source/DotNetGraphQL.API/Data/DogImagesData.cs

@@ -1,14 +1,10 @@
+using System.Threading.Tasks;
 using GraphQL.Validation;
 
 namespace DotNetGraphQL.Common
 {
     public class InputValidationRule : IValidationRule
     {
-        public INodeVisitor Validate(ValidationContext context)
-        {
-            return new EnterLeaveListener(_ =>
-            {
-            });
-        }
+        public Task<INodeVisitor> ValidateAsync(ValidationContext context) => Task.FromResult<INodeVisitor>(new EnterLeaveListener());
     }
 }

Source/DotNetGraphQL.API/DotNetGraphQL.API.csproj

@@ -4,7 +4,9 @@
 using Microsoft.AspNetCore.Builder;
 using Microsoft.AspNetCore.Hosting;
 using Microsoft.AspNetCore.Http;
+using Microsoft.AspNetCore.Server.Kestrel.Core;
 using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Hosting;
 using Microsoft.Extensions.Logging;
 
 namespace DotNetGraphQL.API
@@ -13,6 +15,8 @@ public class Startup
     {
         public void ConfigureServices(IServiceCollection services)
         {
+            services.Configure<KestrelServerOptions>(options => options.AllowSynchronousIO = true);
+
             services.AddSingleton<IDocumentExecuter, DocumentExecuter>();
             services.AddSingleton<IDocumentWriter, DocumentWriter>();
 
@@ -26,10 +30,10 @@ public void ConfigureServices(IServiceCollection services)
             services.AddSingleton<IHttpContextAccessor, HttpContextAccessor>();
         }
 
-        public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory)
+        public void Configure(IApplicationBuilder app, IWebHostEnvironment env, ILoggerFactory loggerFactory)
         {
-            if (env.IsDevelopment())
-                app.UseDeveloperExceptionPage();
+            //if (env.IsDevelopment())
+            //    app.UseDeveloperExceptionPage();
 
             app.UseCors("AllowAll");
 

Source/DotNetGraphQL.API/GraphQLMiddleware.cs

@@ -1,8 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project Sdk="Microsoft.NET.Sdk">
     <PropertyGroup>
-        <TargetFramework>netstandard2.0</TargetFramework>
-        <LangVersion>8.0</LangVersion>
+        <TargetFramework>netstandard2.1</TargetFramework>
         <Nullable>Enable</Nullable>
         <ProduceReferenceAssembly>True</ProduceReferenceAssembly>
     </PropertyGroup>

Source/DotNetGraphQL.API/GraphQLSettings.cs

@@ -61,14 +61,14 @@
         <Reference Include="System.Numerics.Vectors" />
     </ItemGroup>
     <ItemGroup>
-        <PackageReference Include="Xamarin.Forms" Version="4.3.0.947036" />
+        <PackageReference Include="Xamarin.Forms" Version="4.3.0.991211" />
         <PackageReference Include="Xamarin.Essentials" Version="1.3.1" />
-        <PackageReference Include="AsyncAwaitBestPractices.MVVM" Version="3.1.0" />
+        <PackageReference Include="AsyncAwaitBestPractices.MVVM" Version="4.0.0-pre3" />
         <PackageReference Include="Xamarin.FFImageLoading.Forms" Version="2.4.11.982" />
         <PackageReference Include="Xam.Plugins.Forms.ImageCircle" Version="3.0.0.5" />
         <PackageReference Include="modernhttpclient-updated" Version="3.4.2" />
         <PackageReference Include="GraphQL.Client" Version="2.0.0-alpha.3" />
-        <PackageReference Include="Polly" Version="7.1.1" />
+        <PackageReference Include="Polly" Version="7.2.0" />
     </ItemGroup>
     <ItemGroup>
         <Compile Include="MainActivity.cs" />

Source/DotNetGraphQL.API/GraphQLUserContext.cs

@@ -126,14 +126,14 @@
         <Reference Include="System.Numerics.Vectors" />
     </ItemGroup>
     <ItemGroup>
-        <PackageReference Include="Xamarin.Forms" Version="4.3.0.947036" />
+        <PackageReference Include="Xamarin.Forms" Version="4.3.0.991211" />
         <PackageReference Include="Xamarin.Essentials" Version="1.3.1" />
-        <PackageReference Include="AsyncAwaitBestPractices.MVVM" Version="3.1.0" />
+        <PackageReference Include="AsyncAwaitBestPractices.MVVM" Version="4.0.0-pre3" />
         <PackageReference Include="Xamarin.FFImageLoading.Forms" Version="2.4.11.982" />
         <PackageReference Include="Xam.Plugins.Forms.ImageCircle" Version="3.0.0.5" />
         <PackageReference Include="modernhttpclient-updated" Version="3.4.2" />
         <PackageReference Include="GraphQL.Client" Version="2.0.0-alpha.3" />
-        <PackageReference Include="Polly" Version="7.1.1" />
+        <PackageReference Include="Polly" Version="7.2.0" />
     </ItemGroup>
     <ItemGroup>
         <ProjectReference Include="..\DotNetGraphQL.Mobile\DotNetGraphQL.Mobile.csproj">

Source/DotNetGraphQL.API/GraphTypes/DogImagesGraphType.cs

@@ -4,17 +4,16 @@
         <TargetFramework>netstandard2.1</TargetFramework>
         <ProduceReferenceAssembly>true</ProduceReferenceAssembly>
         <Nullable>Enable</Nullable>
-        <ProduceReferenceAssembly>True</ProduceReferenceAssembly>
     </PropertyGroup>
     <ItemGroup>
-        <PackageReference Include="Xamarin.Forms" Version="4.3.0.947036" />
+        <PackageReference Include="Xamarin.Forms" Version="4.3.0.991211" />
         <PackageReference Include="Xamarin.Essentials" Version="1.3.1" />
-        <PackageReference Include="AsyncAwaitBestPractices.MVVM" Version="3.1.0" />
+        <PackageReference Include="AsyncAwaitBestPractices.MVVM" Version="4.0.0-pre3" />
         <PackageReference Include="Xamarin.FFImageLoading.Forms" Version="2.4.11.982" />
         <PackageReference Include="Xam.Plugins.Forms.ImageCircle" Version="3.0.0.5" />
         <PackageReference Include="modernhttpclient-updated" Version="3.4.2" />
         <PackageReference Include="GraphQL.Client" Version="2.0.0-alpha.3" />
-        <PackageReference Include="Polly" Version="7.1.1" />
+        <PackageReference Include="Polly" Version="7.2.0" />
     </ItemGroup>
     <ItemGroup>
       <ProjectReference Include="..\DotNetGraphQL.Common\DotNetGraphQL.Common.csproj" />

Source/DotNetGraphQL.API/GraphTypes/ImagesGraphType.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Collections;
 using System.Threading.Tasks;
 using Xamarin.Essentials;
 using Xamarin.Forms;
@@ -22,10 +23,12 @@ protected override void OnAppearing()
             //If Collection View is Empty, Manually Trigger a Pull-to-Refresh
             if (Content is RefreshView refreshView
                 && refreshView.Content is CollectionView collectionView
-                && !collectionView.ItemsSource.GetEnumerator().MoveNext())
+                && IsNullOrEmpty(collectionView.ItemsSource))
             {
                 refreshView.IsRefreshing = true;
             }
+
+            static bool IsNullOrEmpty(in IEnumerable? enumerable) => !enumerable?.GetEnumerator().MoveNext() ?? true;
         }
 
         protected Task OpenBrowser(Uri uri) => Device.InvokeOnMainThreadAsync(() => Browser.OpenAsync(uri));

Source/DotNetGraphQL.API/InputValidationRule.cs

@@ -1,5 +1,4 @@
-using System.Collections.Generic;
-using System.Linq;
+using System.Linq;
 using DotNetGraphQL.Common;
 using Xamarin.Forms;
 

Source/DotNetGraphQL.API/Program.cs

@@ -50,7 +50,7 @@ static async Task<GraphQLResponse> AttemptAndRetry(Func<Task<GraphQLResponse>> a
 
             return response;
 
-            TimeSpan pollyRetryAttempt(int attemptNumber) => TimeSpan.FromSeconds(Math.Pow(2, attemptNumber));
+            static TimeSpan pollyRetryAttempt(int attemptNumber) => TimeSpan.FromSeconds(Math.Pow(2, attemptNumber));
         }
     }
 }

Source/DotNetGraphQL.API/Public/bundle.js

@@ -1,6 +1,5 @@
 using System;
 using System.Collections.ObjectModel;
-using System.Diagnostics;
 using System.Threading.Tasks;
 using AsyncAwaitBestPractices;
 using AsyncAwaitBestPractices.MVVM;
@@ -27,7 +26,7 @@ public event EventHandler<string> PullToRefreshFailed
         }
 
         public ObservableCollection<DogImagesModel> DogImageCollection { get; } = new ObservableCollection<DogImagesModel>();
-        public AsyncCommand RefreshDogCollectionCommand { get; }
+        public IAsyncCommand RefreshDogCollectionCommand { get; }
 
         public bool IsDogImageCollectionRefreshing
         {