Add support for .NET Core 3.0 (#67)

* Add support .NET Core 3.0

* Update UTF-unknown.csproj

* Fix problem with unicode

We write crutches because it's "best practice"...

* Move to static initializer

* Update UTF-unknown.csproj

* Update image to Visual Studio 2019 for appveyor

* Add netcoreapp3.0 to tests

* Move RegisterProvider to CharsetDetector

* refactor: less code

Author: rstm-sf

appveyor.yml

@@ -4,7 +4,7 @@ environment:
 version: 2.0.{build}
 
 clone_folder: c:\utfUnknown
-image: Visual Studio 2017
+image: Visual Studio 2019
 configuration: Release
 platform: Any CPU
 nuget:

example/ConsoleExample.csproj

@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>netcoreapp1.1</TargetFramework>
+    <TargetFramework>netcoreapp3.0</TargetFramework>
   </PropertyGroup>
 
   <ItemGroup>

example/DetectFile.cs

@@ -1,12 +1,5 @@
-// Udetect.cs created with MonoDevelop
-//
-// Author:
-//    Rudi Pettazzi <rudi.pettazzi@gmail.com>
-//    J. Verdurmen
-//
-
 using System;
-using System.Text;
+using System.IO;
 using UtfUnknown;
 
 namespace ConsoleExample
@@ -17,26 +10,26 @@ public class DetectFile
         /// Command line example: detects the encoding of the given file.
         /// </summary>
         /// <param name="args">a filename</param>
-        public static void Main(String[] args)
+        public static void Main(string[] args)
         {
             if (args.Length == 0)
             {
-                Console.WriteLine("Usage: udetect <filename>");
+                Console.WriteLine("Usage: ConsoleExample <filename>");
                 return;
             }
 
-            string filename = args[0];
-
-            var result = CharsetDetector.DetectFromFile(filename);
-
-            if (result.Detected != null)
+            var filename = args[0];
+            if (!File.Exists(filename))
             {
-                Console.WriteLine("Charset: {0}, confidence: {1}", result.Detected.EncodingName, result.Detected.Confidence);
-            }
-            else
-            {
-                Console.WriteLine("Detection failed.");
+                Console.WriteLine($"File not found: {filename}");
+                return;
             }
+
+            var result = CharsetDetector.DetectFromFile(filename);
+            var message = result.Detected != null
+                ? $"Detected encoding {result.Detected.Encoding.WebName} with confidence {result.Detected.Confidence}."
+                : $"Detection failed: {filename}";
+            Console.WriteLine(message);
         }
     }
 }

src/CharsetDetector.cs

@@ -75,6 +75,16 @@ namespace UtfUnknown
     /// </summary>                
     public class CharsetDetector
     {
+#if NETCOREAPP3_0
+        /// <summary>
+        /// Adds the encodings of the EncodingProvider object to the common language runtime
+        /// </summary>
+        static CharsetDetector()
+        {
+            System.Text.Encoding.RegisterProvider(System.Text.CodePagesEncodingProvider.Instance);
+        }
+#endif // NETCOREAPP3_0
+        
         internal InputState InputState;
 
         /// <summary>

src/UTF-unknown.csproj

@@ -1,17 +1,19 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFrameworks>netstandard1.0;netstandard1.3;net40</TargetFrameworks>
+    <TargetFrameworks>netstandard1.0;netstandard1.3;net40;netcoreapp3.0</TargetFrameworks>
   </PropertyGroup>
+
   <PropertyGroup>
     <AssemblyName>UtfUnknown</AssemblyName>
     <PackageId>UTF.Unknown</PackageId>
     <Version>2.0.0</Version> <!-- patched in AppVeyor.yml -->
-
   </PropertyGroup>
+
   <PropertyGroup>
     <OutputType>Library</OutputType>
   </PropertyGroup>
+
   <PropertyGroup>
     <Authors>Julian Verdurmen, Rudi Pettazzi, Shy Shalom</Authors>
     <NeutralLanguage>en-US</NeutralLanguage>
@@ -21,9 +23,9 @@
       This package is based on Ude and since version 2 also on uchardet, which are ports of the Mozilla Universal Charset Detector.
 
 Features:
-- Detects 28 charsets
-- Easy to use API  
-- .NET standard 1.0 + 2.0 support 
+- Easy to use API
+- .NET standard 1.0 + 2.0 support
+- .NET Core 3.0 support
 - Strong named
 - XML documentation included
 
@@ -33,18 +35,17 @@ Features:
  - Added some docs
  - Improve error handling
  - Improved unit tests
- 
-      
     </Description>
-    <Copyright></Copyright>
+    
+    <Copyright/>
 
   </PropertyGroup>
+
   <PropertyGroup>
 
     <PackageTags>charset;detection;unicode;ascii;netstandard</PackageTags>
     <PackageReleaseNotes>
 - Added support for CP949 (@HelloWorld017)
-    
     </PackageReleaseNotes>
     <PackageIconUrl>https://raw.githubusercontent.com/CharsetDetector/UTF-unknown/master/logo.png</PackageIconUrl>
     <PackageProjectUrl>https://github.com/CharsetDetector/UTF-unknown</PackageProjectUrl>
@@ -56,6 +57,7 @@ Features:
     <SignAssembly>True</SignAssembly>
     <AssemblyOriginatorKeyFile>UtfUnknown.snk</AssemblyOriginatorKeyFile>
   </PropertyGroup>
+  
   <PropertyGroup>
     <DocumentationFile>bin\$(Configuration)\$(TargetFramework)\UtfUnknown.xml</DocumentationFile>
     <NoWarn>1701;1702;1705,1570,1591</NoWarn>

tests/CharsetDetectorTestBatch.cs

@@ -108,9 +108,10 @@ private void TestFile(string expectedCharset, string file)
         {
             var result = CharsetDetector.DetectFromFile(file);
             var detected = result.Detected;
-            
+#if !NETCOREAPP3_0
+            // because System.NotSupportedException in .net core 3.0 for Encoding
             _logWriter.WriteLine(string.Format("- {0} ({1}) -> {2}", file, expectedCharset, JsonConvert.SerializeObject(result)));
-
+#endif // !NETCOREAPP3_0
             StringAssert.AreEqualIgnoringCase(expectedCharset, detected.EncodingName,
                 $"Charset detection failed for {file}. Expected: {expectedCharset}, detected: {detected.EncodingName} ({detected.Confidence * 100.0f:0.00############}% confidence)");
             Assert.NotNull(detected.Encoding);

tests/UTF-unknown.Tests.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFrameworks>net452</TargetFrameworks>
+    <TargetFrameworks>net452;netcoreapp3.0</TargetFrameworks>
     <RootNamespace>UtfUnknown.Tests</RootNamespace>
     <AssemblyName>UtfUnknown.Tests</AssemblyName>
   </PropertyGroup>