Upgrade to C# 7.1 (#145)

* Change csproj files to C# 7.1

* Update SWAN version

* Applying C# 7.1 specs

* Change SWAN to SWAN Lite

* Fix build

src/Unosquare.Labs.EmbedIO.Command/Program.cs

@@ -25,8 +25,6 @@ private static void Main(string[] args)
 
             using (var server = new WebServer($"http://localhost:{options.Port}/"))
             {
-                // TODO: Add AppSettings file
-                //if (Properties.Settings.Default.UseLocalSessionModule)
                 server.WithLocalSession();
 
                 server.EnableCors().WithStaticFolderAt(options.RootPath);

src/Unosquare.Labs.EmbedIO.Command/Unosquare.Labs.EmbedIO.Command.csproj

@@ -8,6 +8,7 @@
     <AssemblyName>Unosquare.Labs.EmbedIO.Command</AssemblyName>
     <OutputType>Exe</OutputType>
     <PackageId>Unosquare.Labs.EmbedIO.Command</PackageId>
+    <LangVersion>7.1</LangVersion>
   </PropertyGroup>
 
   <ItemGroup>

src/Unosquare.Labs.EmbedIO.Samples/Unosquare.Labs.EmbedIO.Samples.csproj

@@ -6,6 +6,7 @@
     <OutputType>Exe</OutputType>
     <PackageId>Unosquare.Labs.EmbedIO.Samples</PackageId>
     <ContentSQLiteInteropFiles>true</ContentSQLiteInteropFiles>
+    <LangVersion>7.1</LangVersion>
   </PropertyGroup>
 
   <ItemGroup>

src/Unosquare.Labs.EmbedIO.Samples/WebSocketsSample.cs

@@ -76,7 +76,7 @@ protected override void OnClientConnected(WebSocketContext context)
         protected override void OnFrameReceived(WebSocketContext context, byte[] rxBuffer,
             WebSocketReceiveResult rxResult)
         {
-            return;
+            // placeholder
         }
 
         /// <inheritdoc />

src/Unosquare.Labs.EmbedIO/Extensions.cs

@@ -416,7 +416,7 @@ public static bool JsonResponse(this HttpListenerContext context, string json)
         public static Task<bool> JsonResponseAsync(
             this HttpListenerContext context,
             string json,
-            CancellationToken cancellationToken = default(CancellationToken))
+            CancellationToken cancellationToken = default)
         {
             return context.StringResponseAsync(json, cancellationToken: cancellationToken);
         }
@@ -433,7 +433,7 @@ public static Task<bool> HtmlResponseAsync(
             this HttpListenerContext context,
             string htmlContent,
             System.Net.HttpStatusCode statusCode = System.Net.HttpStatusCode.OK,
-            CancellationToken cancellationToken = default(CancellationToken))
+            CancellationToken cancellationToken = default)
         {
             context.Response.StatusCode = (int) statusCode;
             return context.StringResponseAsync(htmlContent, Responses.HtmlContentType, cancellationToken);
@@ -484,7 +484,7 @@ public static async Task<bool> StringResponseAsync(
             this HttpListenerContext context,
             string content,
             string contentType = "application/json",
-            CancellationToken cancellationToken = default(CancellationToken),
+            CancellationToken cancellationToken = default,
             Encoding encoding = null)
         {
             var buffer = (encoding ?? Encoding.UTF8).GetBytes(content);

src/Unosquare.Labs.EmbedIO/Modules/WebSocketsModule.cs

@@ -194,7 +194,7 @@ public abstract class WebSocketsServer : IDisposable
         private readonly int _maximumMessageSize;
 #endif
         private bool _isDisposing;
-        private CancellationToken _ct = default(CancellationToken);
+        private CancellationToken _ct = default;
 
         /// <summary>
         /// Initializes a new instance of the <see cref="WebSocketsServer" /> class.

src/Unosquare.Labs.EmbedIO/System.Net/CloseEventArgs.cs

@@ -81,6 +81,30 @@ internal CloseEventArgs(CloseStatusCode code, string reason = null)
 
         internal PayloadData PayloadData { get; }
     }
+
+    /// <summary>
+    /// The event arguments for connection failure events
+    /// </summary>
+    /// <seealso cref="System.EventArgs" />
+    public class ConnectionFailureEventArgs : EventArgs
+    {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="ConnectionFailureEventArgs"/> class.
+        /// </summary>
+        /// <param name="ex">The ex.</param>
+        public ConnectionFailureEventArgs(Exception ex)
+        {
+            Error = ex;
+        }
+
+        /// <summary>
+        /// Gets the error.
+        /// </summary>
+        /// <value>
+        /// The error.
+        /// </value>
+        public Exception Error { get; }
+    }
 }
 
 #endif

src/Unosquare.Labs.EmbedIO/System.Net/HttpBase.cs

@@ -102,7 +102,7 @@ protected static async Task<T> ReadAsync<T>(
             Stream stream, 
             Func<string[], T> parser,
             int millisecondsTimeout = 90000, 
-            CancellationToken ct = default(CancellationToken))
+            CancellationToken ct = default)
             where T : HttpBase
         {
             var timeout = false;

src/Unosquare.Labs.EmbedIO/System.Net/WebSocket.cs

@@ -489,7 +489,7 @@ internal bool HasMessage
         /// <returns>
         /// A task that represents the asynchronous closes websocket connection
         /// </returns>
-        public async Task CloseAsync(CloseStatusCode code = CloseStatusCode.Undefined, string reason = null, CancellationToken ct = default(CancellationToken))
+        public async Task CloseAsync(CloseStatusCode code = CloseStatusCode.Undefined, string reason = null, CancellationToken ct = default)
         {
             if (!_validator.CheckIfAvailable(out var msg))
             {
@@ -532,7 +532,7 @@ internal bool HasMessage
         /// <para>
         /// This method isn't available in a server.
         /// </para></remarks>
-        public async Task ConnectAsync(CancellationToken ct = default(CancellationToken))
+        public async Task ConnectAsync(CancellationToken ct = default)
         {
             if (!_validator.CheckIfAvailable(out string msg, true, false, true, false, false))
             {
@@ -622,7 +622,7 @@ public async Task<bool> PingAsync(string message)
         /// A task that represents the asynchronous of send 
         /// binary data using websocket
         /// </returns>
-        public async Task SendAsync(byte[] data, Opcode opcode, CancellationToken ct = default(CancellationToken))
+        public async Task SendAsync(byte[] data, Opcode opcode, CancellationToken ct = default)
         {
             var msg = WebSocketValidator.CheckIfAvailable(_readyState) ??
                       WebSocketValidator.CheckSendParameter(data);
@@ -714,7 +714,7 @@ internal async Task CloseAsync(HttpResponse response)
         }
 
         // As server
-        internal async Task CloseAsync(CloseEventArgs e, byte[] frameAsBytes, bool receive, CancellationToken ct = default(CancellationToken))
+        internal async Task CloseAsync(CloseEventArgs e, byte[] frameAsBytes, bool receive, CancellationToken ct = default)
         {
             lock (_forState)
             {
@@ -825,7 +825,7 @@ private async Task InternalCloseAsync(
             bool send = true,
             bool receive = true,
             bool received = false,
-            CancellationToken ct = default(CancellationToken))
+            CancellationToken ct = default)
         {
             lock (_forState)
             {

src/Unosquare.Labs.EmbedIO/Unosquare.Labs.EmbedIO.csproj

@@ -20,14 +20,15 @@
     <RepositoryUrl>https://github.com/unosquare/embedio/</RepositoryUrl>
     <RepositoryType>git</RepositoryType>
     <PackageTags>webserver websocket webapi http</PackageTags>
+    <LangVersion>7.1</LangVersion>
   </PropertyGroup>
 
   <ItemGroup>
     <PackageReference Include="Microsoft.DotNet.Analyzers.Compatibility" Version="0.1.2-alpha" />
     <PackageReference Include="StyleCop.Analyzers" Version="1.0.2">
       <PrivateAssets>All</PrivateAssets>
     </PackageReference>
-    <PackageReference Include="Unosquare.Swan" Version="0.24.0" />
+    <PackageReference Include="Unosquare.Swan.Lite" Version="0.25.0" />
   </ItemGroup>
 
   <ItemGroup Condition=" '$(TargetFramework)' == 'uap10.0' ">

src/Unosquare.Labs.EmbedIO/WebServer.cs

@@ -305,7 +305,7 @@ await context.HtmlResponseAsync(
         /// Both the server and client requests are queued separately on the thread pool,
         /// so it is safe to call <see cref="Task.Wait()" /> in a synchronous method.
         /// </remarks>
-        public async Task RunAsync(CancellationToken ct = default(CancellationToken))
+        public async Task RunAsync(CancellationToken ct = default)
         {
             Listener.IgnoreWriteExceptions = true;
             Listener.Start();

test/Unosquare.Labs.EmbedIO.Tests/Unosquare.Labs.EmbedIO.Tests.csproj

@@ -5,6 +5,7 @@
     <TargetFrameworks>net46;net47;netcoreapp2.0</TargetFrameworks>
     <TestProjectType>UnitTest</TestProjectType>
     <CodeAnalysisRuleSet>..\..\StyleCop.Analyzers.ruleset</CodeAnalysisRuleSet>
+    <LangVersion>7.1</LangVersion>
   </PropertyGroup>
 
   <ItemGroup>
@@ -30,6 +31,10 @@
     <DefineConstants>$(DefineConstants);NET47</DefineConstants>
   </PropertyGroup>
 
+  <ItemGroup Condition=" '$(TargetFramework)' == 'net47' ">
+    <Reference Include="System.Net.Http" />
+  </ItemGroup>
+
   <ItemGroup Condition=" '$(TargetFramework)' == 'net46' ">
     <Reference Include="System.Net.Http" />
     <Reference Include="System.Threading.Tasks" />