Add Utf8String package, reference APIs, and unit tests

pkg/Microsoft.Private.PackageBaseline/packageIndex.json

@@ -5307,6 +5307,12 @@
         "uap10.0.16299": "4.0.1.0"
       }
     },
+    "System.Utf8String.Experimental": {
+      "InboxOn": {},
+      "AssemblyVersionInPackageVersion": {
+        "4.0.0.0": "4.6.0"
+      }
+    },
     "System.ValueTuple": {
       "StableVersions": [
         "4.3.0",

pkg/descriptions.json

@@ -2131,6 +2131,14 @@
       "System.Transactions.TransactionScope"
     ]
   },
+  {
+    "Name": "System.Utf8String.Experimental",
+    "Description": "Provides types for representation of UTF-8 string data.",
+    "CommonTypes": [
+        "System.Char8",
+        "System.Utf8String"
+    ]
+  },
   {
     "Name": "System.ValueTuple",
     "Description": "Provides the System.ValueTuple structs, which implement the underlying types for tuples in C# and Visual Basic.",

src/Directory.Build.props

@@ -31,4 +31,13 @@
     <CoverageProbePath Include="shared\Microsoft.NETCore.App\9.9.9\il" />
     <CoverageProbePath Include="shared\Microsoft.NETCore.App\9.9.9" />
   </ItemGroup>
+
+  <!--
+    The Utf8String package is experimental. We don't want tests to inadvertently take a dependency on this
+    feature unless they explicitly opt in to it. (Source projects explicitly reference their dependencies,
+    so they can't inadvertently take a dependency on it.)
+  -->
+  <ItemGroup Condition="'$(IsTestProject)' == 'true' AND '$(IncludeUtf8StringAsmRef)' != 'true'">
+    <DefaultReferenceExclusions Include="System.Utf8String.Experimental" />
+  </ItemGroup>
 </Project>

src/System.Utf8String.Experimental/Directory.Build.props

@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="14.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="..\Directory.Build.props" />
+  <PropertyGroup>
+    <AssemblyVersion>4.0.0.0</AssemblyVersion>
+    <!-- System.Memory uses the Open key, so we will also. -->
+    <StrongNameKeyId>Open</StrongNameKeyId>
+    <!-- This is a preview package. Do not ship as stable. -->
+    <BlockStable>true</BlockStable>
+  </PropertyGroup>
+</Project>

src/System.Utf8String.Experimental/System.Utf8String.Experimental.sln

@@ -0,0 +1,50 @@
+Microsoft Visual Studio Solution File, Format Version 12.00
+# Visual Studio 15
+VisualStudioVersion = 15.0.27213.1
+MinimumVisualStudioVersion = 10.0.40219.1
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "System.Utf8String.Experimental.Tests", "tests\System.Utf8String.Experimental.Tests.csproj", "{72E9FB32-4692-4692-A10B-9F053F8F1A88}"
+	ProjectSection(ProjectDependencies) = postProject
+		{D4266847-6692-481B-9459-6141DB7DA339} = {D4266847-6692-481B-9459-6141DB7DA339}
+	EndProjectSection
+EndProject
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "System.Utf8String.Experimental", "src\System.Utf8String.Experimental.csproj", "{D4266847-6692-481B-9459-6141DB7DA339}"
+EndProject
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "System.Utf8String.Experimental", "ref\System.Utf8String.Experimental.csproj", "{7AF57E6B-2CED-45C9-8BCA-5BBA60D018E0}"
+EndProject
+Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "src", "src", "{7EC8921F-E96F-445B-AA33-453515641D93}"
+EndProject
+Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "ref", "ref", "{8691446A-CA54-49FD-87B9-57A0C6B48095}"
+EndProject
+Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "tests", "tests", "{FEB087F5-EF72-429D-8A0E-7636B84A1537}"
+EndProject
+Global
+	GlobalSection(SolutionConfigurationPlatforms) = preSolution
+		Debug|Any CPU = Debug|Any CPU
+		Release|Any CPU = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{D4266847-6692-481B-9459-6141DB7DA339}.Debug|Any CPU.ActiveCfg = netcoreapp-Debug|Any CPU
+		{D4266847-6692-481B-9459-6141DB7DA339}.Debug|Any CPU.Build.0 = netcoreapp-Debug|Any CPU
+		{D4266847-6692-481B-9459-6141DB7DA339}.Release|Any CPU.ActiveCfg = netcoreapp-Release|Any CPU
+		{D4266847-6692-481B-9459-6141DB7DA339}.Release|Any CPU.Build.0 = netcoreapp-Release|Any CPU
+		{7AF57E6B-2CED-45C9-8BCA-5BBA60D018E0}.Debug|Any CPU.ActiveCfg = netcoreapp-Debug|Any CPU
+		{7AF57E6B-2CED-45C9-8BCA-5BBA60D018E0}.Debug|Any CPU.Build.0 = netcoreapp-Debug|Any CPU
+		{7AF57E6B-2CED-45C9-8BCA-5BBA60D018E0}.Release|Any CPU.ActiveCfg = netcoreapp-Release|Any CPU
+		{7AF57E6B-2CED-45C9-8BCA-5BBA60D018E0}.Release|Any CPU.Build.0 = netcoreapp-Release|Any CPU
+		{72E9FB32-4692-4692-A10B-9F053F8F1A88}.Debug|Any CPU.ActiveCfg = netcoreapp-Debug|Any CPU
+		{72E9FB32-4692-4692-A10B-9F053F8F1A88}.Debug|Any CPU.Build.0 = netcoreapp-Debug|Any CPU
+		{72E9FB32-4692-4692-A10B-9F053F8F1A88}.Release|Any CPU.ActiveCfg = netcoreapp-Release|Any CPU
+		{72E9FB32-4692-4692-A10B-9F053F8F1A88}.Release|Any CPU.Build.0 = netcoreapp-Release|Any CPU
+	EndGlobalSection
+	GlobalSection(SolutionProperties) = preSolution
+		HideSolutionNode = FALSE
+	EndGlobalSection
+	GlobalSection(NestedProjects) = preSolution
+		{D4266847-6692-481B-9459-6141DB7DA339} = {7EC8921F-E96F-445B-AA33-453515641D93}
+		{7AF57E6B-2CED-45C9-8BCA-5BBA60D018E0} = {8691446A-CA54-49FD-87B9-57A0C6B48095}
+		{72E9FB32-4692-4692-A10B-9F053F8F1A88} = {FEB087F5-EF72-429D-8A0E-7636B84A1537}
+	EndGlobalSection
+	GlobalSection(ExtensibilityGlobals) = postSolution
+		SolutionGuid = {7196F6AB-8F22-4E4D-B6D1-3C2CFF86229C}
+	EndGlobalSection
+EndGlobal

src/System.Utf8String.Experimental/pkg/System.Utf8String.Experimental.pkgproj

@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="14.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), Directory.Build.props))\Directory.Build.props" />
+  <ItemGroup>
+    <ProjectReference Include="..\ref\System.Utf8String.Experimental.csproj">
+        <SupportedFramework>netcoreapp3.0;</SupportedFramework>
+    </ProjectReference>
+    <ProjectReference Include="..\src\System.Utf8String.Experimental.csproj" />
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), Directory.Build.targets))\Directory.Build.targets" />
+</Project>

src/System.Utf8String.Experimental/ref/Configurations.props

@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="14.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <PropertyGroup>
+    <BuildConfigurations>
+      netcoreapp;
+    </BuildConfigurations>
+  </PropertyGroup>
+</Project>

src/System.Utf8String.Experimental/ref/System.Utf8String.Experimental.csproj

@@ -0,0 +1,16 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
+    <ProjectGuid>{7AF57E6B-2CED-45C9-8BCA-5BBA60D018E0}</ProjectGuid>
+    <Configurations>netcoreapp-Debug;netcoreapp-Release</Configurations>
+  </PropertyGroup>
+  <ItemGroup>
+    <Compile Include="System.Utf8String.cs" />
+  </ItemGroup>
+  <ItemGroup>
+    <ProjectReference Include="..\..\System.Net.Http\ref\System.Net.Http.csproj" />
+    <ProjectReference Include="..\..\System.Net.Primitives\ref\System.Net.Primitives.csproj" />
+    <ProjectReference Include="..\..\System.Runtime\ref\System.Runtime.csproj" />
+    <ProjectReference Include="..\..\System.Runtime.InteropServices\ref\System.Runtime.InteropServices.csproj" />
+  </ItemGroup>
+</Project>

src/System.Utf8String.Experimental/ref/System.Utf8String.cs

@@ -0,0 +1,125 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+// ------------------------------------------------------------------------------
+// Changes to this file must follow the http://aka.ms/api-review process.
+// ------------------------------------------------------------------------------
+
+namespace System
+{
+    public readonly partial struct Char8 : IComparable<Char8>, IEquatable<Char8>
+    {
+        private readonly int _dummy;
+        public static bool operator ==(Char8 left, Char8 right) => throw null;
+        public static bool operator !=(Char8 left, Char8 right) => throw null;
+        public static bool operator <(Char8 left, Char8 right) => throw null;
+        public static bool operator <=(Char8 left, Char8 right) => throw null;
+        public static bool operator >(Char8 left, Char8 right) => throw null;
+        public static bool operator >=(Char8 left, Char8 right) => throw null;
+        public static implicit operator byte(Char8 value) => throw null;
+        [CLSCompliant(false)]
+        public static explicit operator sbyte(Char8 value) => throw null;
+        public static explicit operator char(Char8 value) => throw null;
+        public static implicit operator short(Char8 value) => throw null;
+        [CLSCompliant(false)]
+        public static implicit operator ushort(Char8 value) => throw null;
+        public static implicit operator int(Char8 value) => throw null;
+        [CLSCompliant(false)]
+        public static implicit operator uint(Char8 value) => throw null;
+        public static implicit operator long(Char8 value) => throw null;
+        [CLSCompliant(false)]
+        public static implicit operator ulong(Char8 value) => throw null;
+        public static implicit operator Char8(byte value) => throw null;
+        [CLSCompliant(false)]
+        public static explicit operator Char8(sbyte value) => throw null;
+        public static explicit operator Char8(char value) => throw null;
+        public static explicit operator Char8(short value) => throw null;
+        [CLSCompliant(false)]
+        public static explicit operator Char8(ushort value) => throw null;
+        public static explicit operator Char8(int value) => throw null;
+        [CLSCompliant(false)]
+        public static explicit operator Char8(uint value) => throw null;
+        public static explicit operator Char8(long value) => throw null;
+        [CLSCompliant(false)]
+        public static explicit operator Char8(ulong value) => throw null;
+        public int CompareTo(Char8 other) => throw null;
+        public override bool Equals(object obj) => throw null;
+        public bool Equals(Char8 other) => throw null;
+        public override int GetHashCode() => throw null;
+        public override string ToString() => throw null;
+    }
+    public static partial class Utf8Extensions
+    {
+        public static ReadOnlySpan<byte> AsBytes(this ReadOnlySpan<Char8> text) => throw null;
+        public static ReadOnlySpan<byte> AsBytes(this Utf8String text) => throw null;
+        public static ReadOnlySpan<byte> AsBytes(this Utf8String text, int start) => throw null;
+        public static ReadOnlySpan<byte> AsBytes(this Utf8String text, int start, int length) => throw null;
+        public static ReadOnlySpan<Char8> AsSpan(this Utf8String text) => throw null;
+        public static ReadOnlySpan<Char8> AsSpan(this Utf8String text, int start) => throw null;
+        public static ReadOnlySpan<Char8> AsSpan(this Utf8String text, int start, int length) => throw null;
+        public static ReadOnlyMemory<Char8> AsMemory(this Utf8String text) => throw null;
+        public static ReadOnlyMemory<Char8> AsMemory(this Utf8String text, int start) => throw null;
+        public static ReadOnlyMemory<Char8> AsMemory(this Utf8String text, Index startIndex) => throw null;
+        public static ReadOnlyMemory<Char8> AsMemory(this Utf8String text, int start, int length) => throw null;
+        public static ReadOnlyMemory<Char8> AsMemory(this Utf8String text, Range range) => throw null;
+        public static ReadOnlyMemory<byte> AsMemoryBytes(this Utf8String text) => throw null;
+        public static ReadOnlyMemory<byte> AsMemoryBytes(this Utf8String text, int start) => throw null;
+        public static ReadOnlyMemory<byte> AsMemoryBytes(this Utf8String text, Index startIndex) => throw null;
+        public static ReadOnlyMemory<byte> AsMemoryBytes(this Utf8String text, int start, int length) => throw null;
+        public static ReadOnlyMemory<byte> AsMemoryBytes(this Utf8String text, Range range) => throw null;
+    }
+    public sealed partial class Utf8String : IEquatable<Utf8String>
+    {
+        public static readonly Utf8String Empty;
+        public Utf8String(ReadOnlySpan<byte> value) { }
+        public Utf8String(byte[] value, int startIndex, int length) { }
+        [CLSCompliant(false)]
+        public unsafe Utf8String(byte* value) { }
+        public Utf8String(ReadOnlySpan<char> value) { }
+        public Utf8String(char[] value, int startIndex, int length) { }
+        [CLSCompliant(false)]
+        public unsafe Utf8String(char* value) { }
+        public Utf8String(string value) { }
+        public static explicit operator ReadOnlySpan<byte>(Utf8String value) => throw null;
+        public static implicit operator ReadOnlySpan<Char8>(Utf8String value) => throw null;
+        public static bool operator ==(Utf8String left, Utf8String right) => throw null;
+        public static bool operator !=(Utf8String left, Utf8String right) => throw null;
+        public Char8 this[Index index] => throw null;
+        public Char8 this[int index] => throw null;
+        public Utf8String this[Range range] => throw null;
+        public int Length => throw null;
+        public bool Contains(char value) => throw null;
+        public bool Contains(System.Text.Rune value) => throw null;
+        public bool EndsWith(char value) => throw null;
+        public bool EndsWith(System.Text.Rune value) => throw null;
+        public override bool Equals(object obj) => throw null;
+        public bool Equals(Utf8String value) => throw null;
+        public static bool Equals(Utf8String left, Utf8String right) => throw null;
+        public override int GetHashCode() => throw null;
+        [ComponentModel.EditorBrowsable(ComponentModel.EditorBrowsableState.Never)] // for compiler use only
+        public ref readonly byte GetPinnableReference() => throw null;
+        public int IndexOf(char value) => throw null;
+        public int IndexOf(System.Text.Rune value) => throw null;
+        public static bool IsNullOrEmpty(Utf8String value) => throw null;
+        public bool StartsWith(char value) => throw null;
+        public bool StartsWith(System.Text.Rune value) => throw null;
+        public Utf8String Substring(Index startIndex) => throw null;
+        public Utf8String Substring(int startIndex) => throw null;
+        public Utf8String Substring(int startIndex, int length) => throw null;
+        public Utf8String Substring(Range range) => throw null;
+        public byte[] ToByteArray() => throw null;
+        public byte[] ToByteArray(int startIndex, int length) => throw null;
+        public override string ToString() => throw null;
+    }
+}
+namespace System.Net.Http
+{
+    public sealed partial class Utf8StringContent : System.Net.Http.HttpContent
+    {
+        public Utf8StringContent(Utf8String content) { }
+        public Utf8StringContent(Utf8String content, string mediaType) { }
+        protected override System.Threading.Tasks.Task<System.IO.Stream> CreateContentReadStreamAsync() => throw null;
+        protected override System.Threading.Tasks.Task SerializeToStreamAsync(System.IO.Stream stream, System.Net.TransportContext context) => throw null;
+        protected override bool TryComputeLength(out long length) => throw null;
+    }
+}

src/System.Utf8String.Experimental/src/Configurations.props

@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="14.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <PropertyGroup>
+    <BuildConfigurations>
+      netcoreapp-Windows_NT;
+      netcoreapp-Unix;
+    </BuildConfigurations>
+  </PropertyGroup>
+</Project>