From 222043719d772ca9abea2131dce6412ef1b2a159 Mon Sep 17 00:00:00 2001
From: Maryam Ariyan <maryam.ariyan@microsoft.com>
Date: Mon, 2 Mar 2020 13:58:22 -0800
Subject: [PATCH] Setup build/pkg on Microsoft.Extensions.Primitives - Fix
 ref/src build on supported frameworks - Use GenerateReferenceSource to
 properly set ref APIs - Enable tests - Add packaging setup

---
 src/libraries/Directory.Build.props           |   7 +-
 .../Microsoft.Extensions.Primitives.pkgproj   |   9 +
 ....cs => Microsoft.Extensions.Primitives.cs} |  53 +++--
 .../Microsoft.Extensions.Primitives.csproj    |  10 +-
 ...ft.Extensions.Primitives.netstandard2.0.cs | 203 ------------------
 .../src/CancellationChangeToken.cs            |   2 +-
 .../Microsoft.Extensions.Primitives.csproj    |  45 ++--
 .../Strings.resx}                             |   0
 .../src/StringSegment.cs                      |   4 +-
 .../src/StringSegmentComparer.cs              |   4 +-
 .../src/StringValues.cs                       |   3 +-
 .../src/ThrowHelper.cs                        |   2 +-
 ...crosoft.Extensions.Primitives.Tests.csproj |  13 ++
 src/libraries/pkg/baseline/packageIndex.json  |  22 ++
 src/libraries/pkg/descriptions.json           |   9 +
 15 files changed, 121 insertions(+), 265 deletions(-)
 create mode 100644 src/libraries/Microsoft.Extensions.Primitives/pkg/Microsoft.Extensions.Primitives.pkgproj
 rename src/libraries/Microsoft.Extensions.Primitives/ref/{Microsoft.Extensions.Primitives.netcoreapp.cs => Microsoft.Extensions.Primitives.cs} (77%)
 delete mode 100644 src/libraries/Microsoft.Extensions.Primitives/ref/Microsoft.Extensions.Primitives.netstandard2.0.cs
 rename src/libraries/Microsoft.Extensions.Primitives/src/{Resources.resx => Resources/Strings.resx} (100%)

diff --git a/src/libraries/Directory.Build.props b/src/libraries/Directory.Build.props
index 70d9fd39aa3b24..3aa2471808e575 100644
--- a/src/libraries/Directory.Build.props
+++ b/src/libraries/Directory.Build.props
@@ -5,14 +5,19 @@
   <Import Project="..\..\Directory.Build.props" />
 
   <ItemGroup>
+    <PortedExtensionsProject Include="$(MSBuildThisFileDirectory)Microsoft.Extensions.Primitives\ref\**\*csproj" />
+    <PortedExtensionsProject Include="$(MSBuildThisFileDirectory)Microsoft.Extensions.Primitives\src\**\*csproj" />
+    <PortedExtensionsProject Include="$(MSBuildThisFileDirectory)Microsoft.Extensions.Primitives\tests\**\*csproj" />
     <ProjectExclusions Include="$(MSBuildThisFileDirectory)*\ref\**\Microsoft.Extensions.*proj" Exclude="@(PortedExtensionsProject)" />
     <ProjectExclusions Include="$(MSBuildThisFileDirectory)*\src\**\Microsoft.Extensions.*proj" Exclude="@(PortedExtensionsProject)" />
     <ProjectExclusions Include="$(MSBuildThisFileDirectory)*\tests\**\Microsoft.Extensions.*.Tests.csproj" Exclude="@(PortedExtensionsProject)" />
   </ItemGroup>
 
-  <PropertyGroup Condition="$(MSBuildProjectName.StartsWith('Microsoft.Extensions.')) and !$(MSBuildProjectName.EndsWith('.Tests'))">
+  <PropertyGroup Condition="$(MSBuildProjectName.StartsWith('Microsoft.Extensions.'))">
     <StrongNameKeyId>MicrosoftAspNetCore</StrongNameKeyId>
     <IsAspNetCoreApp>true</IsAspNetCoreApp>
+    <!-- Temporarily ignore nit warning/errors (e.g. extra whitespace) from Extensions projects -->
+    <NoWarn Condition="!$(MSBuildProjectName.EndsWith('.Tests'))">$(NoWarn);SA1129;SA1028;SA1027;SA1121;CA1200</NoWarn>
   </PropertyGroup>
 
   <PropertyGroup>
diff --git a/src/libraries/Microsoft.Extensions.Primitives/pkg/Microsoft.Extensions.Primitives.pkgproj b/src/libraries/Microsoft.Extensions.Primitives/pkg/Microsoft.Extensions.Primitives.pkgproj
new file mode 100644
index 00000000000000..07273ae288cef3
--- /dev/null
+++ b/src/libraries/Microsoft.Extensions.Primitives/pkg/Microsoft.Extensions.Primitives.pkgproj
@@ -0,0 +1,9 @@
+<Project DefaultTargets="Build">
+  <Import Project="$([MSBuild]::GetPathOfFileAbove(Directory.Build.props))" />
+  <ItemGroup>
+    <ProjectReference Include="..\src\Microsoft.Extensions.Primitives.csproj">
+      <SupportedFramework>net461;netcoreapp2.0;uap10.0.16299;$(AllXamarinFrameworks)</SupportedFramework>
+    </ProjectReference>
+  </ItemGroup>
+  <Import Project="$([MSBuild]::GetPathOfFileAbove(Directory.Build.targets))" />
+</Project>
\ No newline at end of file
diff --git a/src/libraries/Microsoft.Extensions.Primitives/ref/Microsoft.Extensions.Primitives.netcoreapp.cs b/src/libraries/Microsoft.Extensions.Primitives/ref/Microsoft.Extensions.Primitives.cs
similarity index 77%
rename from src/libraries/Microsoft.Extensions.Primitives/ref/Microsoft.Extensions.Primitives.netcoreapp.cs
rename to src/libraries/Microsoft.Extensions.Primitives/ref/Microsoft.Extensions.Primitives.cs
index c2397dd21b4e81..37f8f8a869baf7 100644
--- a/src/libraries/Microsoft.Extensions.Primitives/ref/Microsoft.Extensions.Primitives.netcoreapp.cs
+++ b/src/libraries/Microsoft.Extensions.Primitives/ref/Microsoft.Extensions.Primitives.cs
@@ -1,13 +1,16 @@
 // 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 https://aka.ms/api-review process.
+// ------------------------------------------------------------------------------
 
 namespace Microsoft.Extensions.Primitives
 {
     public partial class CancellationChangeToken : Microsoft.Extensions.Primitives.IChangeToken
     {
         public CancellationChangeToken(System.Threading.CancellationToken cancellationToken) { }
-        public bool ActiveChangeCallbacks { [System.Runtime.CompilerServices.CompilerGeneratedAttribute] get { throw null; } }
+        public bool ActiveChangeCallbacks { get { throw null; } }
         public bool HasChanged { get { throw null; } }
         public System.IDisposable RegisterChangeCallback(System.Action<object> callback, object state) { throw null; }
     }
@@ -19,8 +22,8 @@ public static partial class ChangeToken
     public partial class CompositeChangeToken : Microsoft.Extensions.Primitives.IChangeToken
     {
         public CompositeChangeToken(System.Collections.Generic.IReadOnlyList<Microsoft.Extensions.Primitives.IChangeToken> changeTokens) { }
-        public bool ActiveChangeCallbacks { [System.Runtime.CompilerServices.CompilerGeneratedAttribute] get { throw null; } }
-        public System.Collections.Generic.IReadOnlyList<Microsoft.Extensions.Primitives.IChangeToken> ChangeTokens { [System.Runtime.CompilerServices.CompilerGeneratedAttribute] get { throw null; } }
+        public bool ActiveChangeCallbacks { get { throw null; } }
+        public System.Collections.Generic.IReadOnlyList<Microsoft.Extensions.Primitives.IChangeToken> ChangeTokens { get { throw null; } }
         public bool HasChanged { get { throw null; } }
         public System.IDisposable RegisterChangeCallback(System.Action<object> callback, object state) { throw null; }
     }
@@ -34,9 +37,6 @@ public partial interface IChangeToken
         bool HasChanged { get; }
         System.IDisposable RegisterChangeCallback(System.Action<object> callback, object state);
     }
-    [System.Diagnostics.DebuggerDisplayAttribute("Value = {_value}")]
-    [System.ObsoleteAttribute("This type is obsolete and will be removed in a future version.")]
-    [System.Runtime.InteropServices.StructLayoutAttribute(System.Runtime.InteropServices.LayoutKind.Sequential)]
     public partial struct InplaceStringBuilder
     {
         private object _dummy;
@@ -44,42 +44,41 @@ public partial struct InplaceStringBuilder
         public InplaceStringBuilder(int capacity) { throw null; }
         public int Capacity { get { throw null; } set { } }
         public void Append(Microsoft.Extensions.Primitives.StringSegment segment) { }
-        [System.Runtime.CompilerServices.MethodImpl(System.Runtime.CompilerServices.MethodImplOptions.AggressiveInlining)]public void Append(char c) { }
+        public void Append(char c) { }
         public void Append(string value) { }
-        [System.Runtime.CompilerServices.MethodImpl(System.Runtime.CompilerServices.MethodImplOptions.AggressiveInlining)]public void Append(string value, int offset, int count) { }
+        public void Append(string value, int offset, int count) { }
         public override string ToString() { throw null; }
     }
-    [System.Runtime.InteropServices.StructLayoutAttribute(System.Runtime.InteropServices.LayoutKind.Sequential)]
     public readonly partial struct StringSegment : System.IEquatable<Microsoft.Extensions.Primitives.StringSegment>, System.IEquatable<string>
     {
         private readonly object _dummy;
         private readonly int _dummyPrimitive;
         public static readonly Microsoft.Extensions.Primitives.StringSegment Empty;
         public StringSegment(string buffer) { throw null; }
-        [System.Runtime.CompilerServices.MethodImpl(System.Runtime.CompilerServices.MethodImplOptions.AggressiveInlining)]public StringSegment(string buffer, int offset, int length) { throw null; }
-        public string Buffer { [System.Runtime.CompilerServices.CompilerGeneratedAttribute] get { throw null; } }
+        public StringSegment(string buffer, int offset, int length) { throw null; }
+        public string Buffer { get { throw null; } }
         public bool HasValue { get { throw null; } }
         public char this[int index] { get { throw null; } }
-        public int Length { [System.Runtime.CompilerServices.CompilerGeneratedAttribute] get { throw null; } }
-        public int Offset { [System.Runtime.CompilerServices.CompilerGeneratedAttribute] get { throw null; } }
+        public int Length { get { throw null; } }
+        public int Offset { get { throw null; } }
         public string Value { get { throw null; } }
         public System.ReadOnlyMemory<char> AsMemory() { throw null; }
         public System.ReadOnlySpan<char> AsSpan() { throw null; }
         public static int Compare(Microsoft.Extensions.Primitives.StringSegment a, Microsoft.Extensions.Primitives.StringSegment b, System.StringComparison comparisonType) { throw null; }
-        [System.Runtime.CompilerServices.MethodImpl(System.Runtime.CompilerServices.MethodImplOptions.AggressiveInlining)]public bool EndsWith(string text, System.StringComparison comparisonType) { throw null; }
+        public bool EndsWith(string text, System.StringComparison comparisonType) { throw null; }
         public bool Equals(Microsoft.Extensions.Primitives.StringSegment other) { throw null; }
         public static bool Equals(Microsoft.Extensions.Primitives.StringSegment a, Microsoft.Extensions.Primitives.StringSegment b, System.StringComparison comparisonType) { throw null; }
         public bool Equals(Microsoft.Extensions.Primitives.StringSegment other, System.StringComparison comparisonType) { throw null; }
         public override bool Equals(object obj) { throw null; }
         public bool Equals(string text) { throw null; }
-        [System.Runtime.CompilerServices.MethodImpl(System.Runtime.CompilerServices.MethodImplOptions.AggressiveInlining)]public bool Equals(string text, System.StringComparison comparisonType) { throw null; }
-        [System.Runtime.CompilerServices.MethodImpl(System.Runtime.CompilerServices.MethodImplOptions.AggressiveInlining)]public override int GetHashCode() { throw null; }
+        public bool Equals(string text, System.StringComparison comparisonType) { throw null; }
+        public override int GetHashCode() { throw null; }
         public int IndexOf(char c) { throw null; }
         public int IndexOf(char c, int start) { throw null; }
-        [System.Runtime.CompilerServices.MethodImpl(System.Runtime.CompilerServices.MethodImplOptions.AggressiveInlining)]public int IndexOf(char c, int start, int count) { throw null; }
+        public int IndexOf(char c, int start, int count) { throw null; }
         public int IndexOfAny(char[] anyOf) { throw null; }
         public int IndexOfAny(char[] anyOf, int startIndex) { throw null; }
-        [System.Runtime.CompilerServices.MethodImpl(System.Runtime.CompilerServices.MethodImplOptions.AggressiveInlining)]public int IndexOfAny(char[] anyOf, int startIndex, int count) { throw null; }
+        public int IndexOfAny(char[] anyOf, int startIndex, int count) { throw null; }
         public static bool IsNullOrEmpty(Microsoft.Extensions.Primitives.StringSegment value) { throw null; }
         public int LastIndexOf(char value) { throw null; }
         public static bool operator ==(Microsoft.Extensions.Primitives.StringSegment left, Microsoft.Extensions.Primitives.StringSegment right) { throw null; }
@@ -88,11 +87,11 @@ public void Append(string value) { }
         public static implicit operator Microsoft.Extensions.Primitives.StringSegment (string value) { throw null; }
         public static bool operator !=(Microsoft.Extensions.Primitives.StringSegment left, Microsoft.Extensions.Primitives.StringSegment right) { throw null; }
         public Microsoft.Extensions.Primitives.StringTokenizer Split(char[] chars) { throw null; }
-        [System.Runtime.CompilerServices.MethodImpl(System.Runtime.CompilerServices.MethodImplOptions.AggressiveInlining)]public bool StartsWith(string text, System.StringComparison comparisonType) { throw null; }
+        public bool StartsWith(string text, System.StringComparison comparisonType) { throw null; }
         public Microsoft.Extensions.Primitives.StringSegment Subsegment(int offset) { throw null; }
         public Microsoft.Extensions.Primitives.StringSegment Subsegment(int offset, int length) { throw null; }
         public string Substring(int offset) { throw null; }
-        [System.Runtime.CompilerServices.MethodImpl(System.Runtime.CompilerServices.MethodImplOptions.AggressiveInlining)]public string Substring(int offset, int length) { throw null; }
+        public string Substring(int offset, int length) { throw null; }
         public override string ToString() { throw null; }
         public Microsoft.Extensions.Primitives.StringSegment Trim() { throw null; }
         public Microsoft.Extensions.Primitives.StringSegment TrimEnd() { throw null; }
@@ -101,13 +100,12 @@ public void Append(string value) { }
     public partial class StringSegmentComparer : System.Collections.Generic.IComparer<Microsoft.Extensions.Primitives.StringSegment>, System.Collections.Generic.IEqualityComparer<Microsoft.Extensions.Primitives.StringSegment>
     {
         internal StringSegmentComparer() { }
-        public static Microsoft.Extensions.Primitives.StringSegmentComparer Ordinal { [System.Runtime.CompilerServices.CompilerGeneratedAttribute] get { throw null; } }
-        public static Microsoft.Extensions.Primitives.StringSegmentComparer OrdinalIgnoreCase { [System.Runtime.CompilerServices.CompilerGeneratedAttribute] get { throw null; } }
+        public static Microsoft.Extensions.Primitives.StringSegmentComparer Ordinal { get { throw null; } }
+        public static Microsoft.Extensions.Primitives.StringSegmentComparer OrdinalIgnoreCase { get { throw null; } }
         public int Compare(Microsoft.Extensions.Primitives.StringSegment x, Microsoft.Extensions.Primitives.StringSegment y) { throw null; }
         public bool Equals(Microsoft.Extensions.Primitives.StringSegment x, Microsoft.Extensions.Primitives.StringSegment y) { throw null; }
         public int GetHashCode(Microsoft.Extensions.Primitives.StringSegment obj) { throw null; }
     }
-    [System.Runtime.InteropServices.StructLayoutAttribute(System.Runtime.InteropServices.LayoutKind.Sequential)]
     public readonly partial struct StringTokenizer : System.Collections.Generic.IEnumerable<Microsoft.Extensions.Primitives.StringSegment>, System.Collections.IEnumerable
     {
         private readonly object _dummy;
@@ -117,20 +115,18 @@ internal StringSegmentComparer() { }
         public Microsoft.Extensions.Primitives.StringTokenizer.Enumerator GetEnumerator() { throw null; }
         System.Collections.Generic.IEnumerator<Microsoft.Extensions.Primitives.StringSegment> System.Collections.Generic.IEnumerable<Microsoft.Extensions.Primitives.StringSegment>.GetEnumerator() { throw null; }
         System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator() { throw null; }
-        [System.Runtime.InteropServices.StructLayoutAttribute(System.Runtime.InteropServices.LayoutKind.Sequential)]
         public partial struct Enumerator : System.Collections.Generic.IEnumerator<Microsoft.Extensions.Primitives.StringSegment>, System.Collections.IEnumerator, System.IDisposable
         {
             private object _dummy;
             private int _dummyPrimitive;
             public Enumerator(ref Microsoft.Extensions.Primitives.StringTokenizer tokenizer) { throw null; }
-            public Microsoft.Extensions.Primitives.StringSegment Current { [System.Runtime.CompilerServices.CompilerGeneratedAttribute] get { throw null; } }
+            public readonly Microsoft.Extensions.Primitives.StringSegment Current { get { throw null; } }
             object System.Collections.IEnumerator.Current { get { throw null; } }
             public void Dispose() { }
             public bool MoveNext() { throw null; }
             public void Reset() { }
         }
     }
-    [System.Runtime.InteropServices.StructLayoutAttribute(System.Runtime.InteropServices.LayoutKind.Sequential)]
     public readonly partial struct StringValues : System.Collections.Generic.ICollection<string>, System.Collections.Generic.IEnumerable<string>, System.Collections.Generic.IList<string>, System.Collections.Generic.IReadOnlyCollection<string>, System.Collections.Generic.IReadOnlyList<string>, System.Collections.IEnumerable, System.IEquatable<Microsoft.Extensions.Primitives.StringValues>, System.IEquatable<string>, System.IEquatable<string[]>
     {
         private readonly object _dummy;
@@ -138,8 +134,8 @@ public void Reset() { }
         public static readonly Microsoft.Extensions.Primitives.StringValues Empty;
         public StringValues(string value) { throw null; }
         public StringValues(string[] values) { throw null; }
-        public int Count { [System.Runtime.CompilerServices.MethodImpl(System.Runtime.CompilerServices.MethodImplOptions.AggressiveInlining)]get { throw null; } }
-        public string this[int index] { [System.Runtime.CompilerServices.MethodImpl(System.Runtime.CompilerServices.MethodImplOptions.AggressiveInlining)]get { throw null; } }
+        public int Count { get { throw null; } }
+        public string this[int index] { get { throw null; } }
         bool System.Collections.Generic.ICollection<System.String>.IsReadOnly { get { throw null; } }
         string System.Collections.Generic.IList<System.String>.this[int index] { get { throw null; } set { } }
         public static Microsoft.Extensions.Primitives.StringValues Concat(Microsoft.Extensions.Primitives.StringValues values1, Microsoft.Extensions.Primitives.StringValues values2) { throw null; }
@@ -187,7 +183,6 @@ public void Reset() { }
         System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator() { throw null; }
         public string[] ToArray() { throw null; }
         public override string ToString() { throw null; }
-        [System.Runtime.InteropServices.StructLayoutAttribute(System.Runtime.InteropServices.LayoutKind.Sequential)]
         public partial struct Enumerator : System.Collections.Generic.IEnumerator<string>, System.Collections.IEnumerator, System.IDisposable
         {
             private object _dummy;
diff --git a/src/libraries/Microsoft.Extensions.Primitives/ref/Microsoft.Extensions.Primitives.csproj b/src/libraries/Microsoft.Extensions.Primitives/ref/Microsoft.Extensions.Primitives.csproj
index 9623f02f73388d..a96a2cac069ce3 100644
--- a/src/libraries/Microsoft.Extensions.Primitives/ref/Microsoft.Extensions.Primitives.csproj
+++ b/src/libraries/Microsoft.Extensions.Primitives/ref/Microsoft.Extensions.Primitives.csproj
@@ -1,15 +1,11 @@
-<!-- This file is automatically generated. -->
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>netstandard2.0;$(DefaultNetCoreTargetFramework)</TargetFrameworks>
+    <TargetFrameworks>netstandard2.0;netstandard2.1</TargetFrameworks>
   </PropertyGroup>
   <ItemGroup Condition="'$(TargetFramework)' == 'netstandard2.0'">
-    <Compile Include="Microsoft.Extensions.Primitives.netstandard2.0.cs" />
     <Reference Include="System.Memory"  />
-    <Reference Include="System.Runtime.CompilerServices.Unsafe"  />
   </ItemGroup>
-<ItemGroup Condition="'$(TargetFramework)' == '$(DefaultNetCoreTargetFramework)'">
-    <Compile Include="Microsoft.Extensions.Primitives.netcoreapp.cs" />
-    
+  <ItemGroup>
+    <Compile Include="Microsoft.Extensions.Primitives.cs" />
   </ItemGroup>
 </Project>
diff --git a/src/libraries/Microsoft.Extensions.Primitives/ref/Microsoft.Extensions.Primitives.netstandard2.0.cs b/src/libraries/Microsoft.Extensions.Primitives/ref/Microsoft.Extensions.Primitives.netstandard2.0.cs
deleted file mode 100644
index c2397dd21b4e81..00000000000000
--- a/src/libraries/Microsoft.Extensions.Primitives/ref/Microsoft.Extensions.Primitives.netstandard2.0.cs
+++ /dev/null
@@ -1,203 +0,0 @@
-// 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.
-
-namespace Microsoft.Extensions.Primitives
-{
-    public partial class CancellationChangeToken : Microsoft.Extensions.Primitives.IChangeToken
-    {
-        public CancellationChangeToken(System.Threading.CancellationToken cancellationToken) { }
-        public bool ActiveChangeCallbacks { [System.Runtime.CompilerServices.CompilerGeneratedAttribute] get { throw null; } }
-        public bool HasChanged { get { throw null; } }
-        public System.IDisposable RegisterChangeCallback(System.Action<object> callback, object state) { throw null; }
-    }
-    public static partial class ChangeToken
-    {
-        public static System.IDisposable OnChange(System.Func<Microsoft.Extensions.Primitives.IChangeToken> changeTokenProducer, System.Action changeTokenConsumer) { throw null; }
-        public static System.IDisposable OnChange<TState>(System.Func<Microsoft.Extensions.Primitives.IChangeToken> changeTokenProducer, System.Action<TState> changeTokenConsumer, TState state) { throw null; }
-    }
-    public partial class CompositeChangeToken : Microsoft.Extensions.Primitives.IChangeToken
-    {
-        public CompositeChangeToken(System.Collections.Generic.IReadOnlyList<Microsoft.Extensions.Primitives.IChangeToken> changeTokens) { }
-        public bool ActiveChangeCallbacks { [System.Runtime.CompilerServices.CompilerGeneratedAttribute] get { throw null; } }
-        public System.Collections.Generic.IReadOnlyList<Microsoft.Extensions.Primitives.IChangeToken> ChangeTokens { [System.Runtime.CompilerServices.CompilerGeneratedAttribute] get { throw null; } }
-        public bool HasChanged { get { throw null; } }
-        public System.IDisposable RegisterChangeCallback(System.Action<object> callback, object state) { throw null; }
-    }
-    public static partial class Extensions
-    {
-        public static System.Text.StringBuilder Append(this System.Text.StringBuilder builder, Microsoft.Extensions.Primitives.StringSegment segment) { throw null; }
-    }
-    public partial interface IChangeToken
-    {
-        bool ActiveChangeCallbacks { get; }
-        bool HasChanged { get; }
-        System.IDisposable RegisterChangeCallback(System.Action<object> callback, object state);
-    }
-    [System.Diagnostics.DebuggerDisplayAttribute("Value = {_value}")]
-    [System.ObsoleteAttribute("This type is obsolete and will be removed in a future version.")]
-    [System.Runtime.InteropServices.StructLayoutAttribute(System.Runtime.InteropServices.LayoutKind.Sequential)]
-    public partial struct InplaceStringBuilder
-    {
-        private object _dummy;
-        private int _dummyPrimitive;
-        public InplaceStringBuilder(int capacity) { throw null; }
-        public int Capacity { get { throw null; } set { } }
-        public void Append(Microsoft.Extensions.Primitives.StringSegment segment) { }
-        [System.Runtime.CompilerServices.MethodImpl(System.Runtime.CompilerServices.MethodImplOptions.AggressiveInlining)]public void Append(char c) { }
-        public void Append(string value) { }
-        [System.Runtime.CompilerServices.MethodImpl(System.Runtime.CompilerServices.MethodImplOptions.AggressiveInlining)]public void Append(string value, int offset, int count) { }
-        public override string ToString() { throw null; }
-    }
-    [System.Runtime.InteropServices.StructLayoutAttribute(System.Runtime.InteropServices.LayoutKind.Sequential)]
-    public readonly partial struct StringSegment : System.IEquatable<Microsoft.Extensions.Primitives.StringSegment>, System.IEquatable<string>
-    {
-        private readonly object _dummy;
-        private readonly int _dummyPrimitive;
-        public static readonly Microsoft.Extensions.Primitives.StringSegment Empty;
-        public StringSegment(string buffer) { throw null; }
-        [System.Runtime.CompilerServices.MethodImpl(System.Runtime.CompilerServices.MethodImplOptions.AggressiveInlining)]public StringSegment(string buffer, int offset, int length) { throw null; }
-        public string Buffer { [System.Runtime.CompilerServices.CompilerGeneratedAttribute] get { throw null; } }
-        public bool HasValue { get { throw null; } }
-        public char this[int index] { get { throw null; } }
-        public int Length { [System.Runtime.CompilerServices.CompilerGeneratedAttribute] get { throw null; } }
-        public int Offset { [System.Runtime.CompilerServices.CompilerGeneratedAttribute] get { throw null; } }
-        public string Value { get { throw null; } }
-        public System.ReadOnlyMemory<char> AsMemory() { throw null; }
-        public System.ReadOnlySpan<char> AsSpan() { throw null; }
-        public static int Compare(Microsoft.Extensions.Primitives.StringSegment a, Microsoft.Extensions.Primitives.StringSegment b, System.StringComparison comparisonType) { throw null; }
-        [System.Runtime.CompilerServices.MethodImpl(System.Runtime.CompilerServices.MethodImplOptions.AggressiveInlining)]public bool EndsWith(string text, System.StringComparison comparisonType) { throw null; }
-        public bool Equals(Microsoft.Extensions.Primitives.StringSegment other) { throw null; }
-        public static bool Equals(Microsoft.Extensions.Primitives.StringSegment a, Microsoft.Extensions.Primitives.StringSegment b, System.StringComparison comparisonType) { throw null; }
-        public bool Equals(Microsoft.Extensions.Primitives.StringSegment other, System.StringComparison comparisonType) { throw null; }
-        public override bool Equals(object obj) { throw null; }
-        public bool Equals(string text) { throw null; }
-        [System.Runtime.CompilerServices.MethodImpl(System.Runtime.CompilerServices.MethodImplOptions.AggressiveInlining)]public bool Equals(string text, System.StringComparison comparisonType) { throw null; }
-        [System.Runtime.CompilerServices.MethodImpl(System.Runtime.CompilerServices.MethodImplOptions.AggressiveInlining)]public override int GetHashCode() { throw null; }
-        public int IndexOf(char c) { throw null; }
-        public int IndexOf(char c, int start) { throw null; }
-        [System.Runtime.CompilerServices.MethodImpl(System.Runtime.CompilerServices.MethodImplOptions.AggressiveInlining)]public int IndexOf(char c, int start, int count) { throw null; }
-        public int IndexOfAny(char[] anyOf) { throw null; }
-        public int IndexOfAny(char[] anyOf, int startIndex) { throw null; }
-        [System.Runtime.CompilerServices.MethodImpl(System.Runtime.CompilerServices.MethodImplOptions.AggressiveInlining)]public int IndexOfAny(char[] anyOf, int startIndex, int count) { throw null; }
-        public static bool IsNullOrEmpty(Microsoft.Extensions.Primitives.StringSegment value) { throw null; }
-        public int LastIndexOf(char value) { throw null; }
-        public static bool operator ==(Microsoft.Extensions.Primitives.StringSegment left, Microsoft.Extensions.Primitives.StringSegment right) { throw null; }
-        public static implicit operator System.ReadOnlyMemory<char> (Microsoft.Extensions.Primitives.StringSegment segment) { throw null; }
-        public static implicit operator System.ReadOnlySpan<char> (Microsoft.Extensions.Primitives.StringSegment segment) { throw null; }
-        public static implicit operator Microsoft.Extensions.Primitives.StringSegment (string value) { throw null; }
-        public static bool operator !=(Microsoft.Extensions.Primitives.StringSegment left, Microsoft.Extensions.Primitives.StringSegment right) { throw null; }
-        public Microsoft.Extensions.Primitives.StringTokenizer Split(char[] chars) { throw null; }
-        [System.Runtime.CompilerServices.MethodImpl(System.Runtime.CompilerServices.MethodImplOptions.AggressiveInlining)]public bool StartsWith(string text, System.StringComparison comparisonType) { throw null; }
-        public Microsoft.Extensions.Primitives.StringSegment Subsegment(int offset) { throw null; }
-        public Microsoft.Extensions.Primitives.StringSegment Subsegment(int offset, int length) { throw null; }
-        public string Substring(int offset) { throw null; }
-        [System.Runtime.CompilerServices.MethodImpl(System.Runtime.CompilerServices.MethodImplOptions.AggressiveInlining)]public string Substring(int offset, int length) { throw null; }
-        public override string ToString() { throw null; }
-        public Microsoft.Extensions.Primitives.StringSegment Trim() { throw null; }
-        public Microsoft.Extensions.Primitives.StringSegment TrimEnd() { throw null; }
-        public Microsoft.Extensions.Primitives.StringSegment TrimStart() { throw null; }
-    }
-    public partial class StringSegmentComparer : System.Collections.Generic.IComparer<Microsoft.Extensions.Primitives.StringSegment>, System.Collections.Generic.IEqualityComparer<Microsoft.Extensions.Primitives.StringSegment>
-    {
-        internal StringSegmentComparer() { }
-        public static Microsoft.Extensions.Primitives.StringSegmentComparer Ordinal { [System.Runtime.CompilerServices.CompilerGeneratedAttribute] get { throw null; } }
-        public static Microsoft.Extensions.Primitives.StringSegmentComparer OrdinalIgnoreCase { [System.Runtime.CompilerServices.CompilerGeneratedAttribute] get { throw null; } }
-        public int Compare(Microsoft.Extensions.Primitives.StringSegment x, Microsoft.Extensions.Primitives.StringSegment y) { throw null; }
-        public bool Equals(Microsoft.Extensions.Primitives.StringSegment x, Microsoft.Extensions.Primitives.StringSegment y) { throw null; }
-        public int GetHashCode(Microsoft.Extensions.Primitives.StringSegment obj) { throw null; }
-    }
-    [System.Runtime.InteropServices.StructLayoutAttribute(System.Runtime.InteropServices.LayoutKind.Sequential)]
-    public readonly partial struct StringTokenizer : System.Collections.Generic.IEnumerable<Microsoft.Extensions.Primitives.StringSegment>, System.Collections.IEnumerable
-    {
-        private readonly object _dummy;
-        private readonly int _dummyPrimitive;
-        public StringTokenizer(Microsoft.Extensions.Primitives.StringSegment value, char[] separators) { throw null; }
-        public StringTokenizer(string value, char[] separators) { throw null; }
-        public Microsoft.Extensions.Primitives.StringTokenizer.Enumerator GetEnumerator() { throw null; }
-        System.Collections.Generic.IEnumerator<Microsoft.Extensions.Primitives.StringSegment> System.Collections.Generic.IEnumerable<Microsoft.Extensions.Primitives.StringSegment>.GetEnumerator() { throw null; }
-        System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator() { throw null; }
-        [System.Runtime.InteropServices.StructLayoutAttribute(System.Runtime.InteropServices.LayoutKind.Sequential)]
-        public partial struct Enumerator : System.Collections.Generic.IEnumerator<Microsoft.Extensions.Primitives.StringSegment>, System.Collections.IEnumerator, System.IDisposable
-        {
-            private object _dummy;
-            private int _dummyPrimitive;
-            public Enumerator(ref Microsoft.Extensions.Primitives.StringTokenizer tokenizer) { throw null; }
-            public Microsoft.Extensions.Primitives.StringSegment Current { [System.Runtime.CompilerServices.CompilerGeneratedAttribute] get { throw null; } }
-            object System.Collections.IEnumerator.Current { get { throw null; } }
-            public void Dispose() { }
-            public bool MoveNext() { throw null; }
-            public void Reset() { }
-        }
-    }
-    [System.Runtime.InteropServices.StructLayoutAttribute(System.Runtime.InteropServices.LayoutKind.Sequential)]
-    public readonly partial struct StringValues : System.Collections.Generic.ICollection<string>, System.Collections.Generic.IEnumerable<string>, System.Collections.Generic.IList<string>, System.Collections.Generic.IReadOnlyCollection<string>, System.Collections.Generic.IReadOnlyList<string>, System.Collections.IEnumerable, System.IEquatable<Microsoft.Extensions.Primitives.StringValues>, System.IEquatable<string>, System.IEquatable<string[]>
-    {
-        private readonly object _dummy;
-        private readonly int _dummyPrimitive;
-        public static readonly Microsoft.Extensions.Primitives.StringValues Empty;
-        public StringValues(string value) { throw null; }
-        public StringValues(string[] values) { throw null; }
-        public int Count { [System.Runtime.CompilerServices.MethodImpl(System.Runtime.CompilerServices.MethodImplOptions.AggressiveInlining)]get { throw null; } }
-        public string this[int index] { [System.Runtime.CompilerServices.MethodImpl(System.Runtime.CompilerServices.MethodImplOptions.AggressiveInlining)]get { throw null; } }
-        bool System.Collections.Generic.ICollection<System.String>.IsReadOnly { get { throw null; } }
-        string System.Collections.Generic.IList<System.String>.this[int index] { get { throw null; } set { } }
-        public static Microsoft.Extensions.Primitives.StringValues Concat(Microsoft.Extensions.Primitives.StringValues values1, Microsoft.Extensions.Primitives.StringValues values2) { throw null; }
-        public static Microsoft.Extensions.Primitives.StringValues Concat(in Microsoft.Extensions.Primitives.StringValues values, string value) { throw null; }
-        public static Microsoft.Extensions.Primitives.StringValues Concat(string value, in Microsoft.Extensions.Primitives.StringValues values) { throw null; }
-        public bool Equals(Microsoft.Extensions.Primitives.StringValues other) { throw null; }
-        public static bool Equals(Microsoft.Extensions.Primitives.StringValues left, Microsoft.Extensions.Primitives.StringValues right) { throw null; }
-        public static bool Equals(Microsoft.Extensions.Primitives.StringValues left, string right) { throw null; }
-        public static bool Equals(Microsoft.Extensions.Primitives.StringValues left, string[] right) { throw null; }
-        public override bool Equals(object obj) { throw null; }
-        public bool Equals(string other) { throw null; }
-        public static bool Equals(string left, Microsoft.Extensions.Primitives.StringValues right) { throw null; }
-        public bool Equals(string[] other) { throw null; }
-        public static bool Equals(string[] left, Microsoft.Extensions.Primitives.StringValues right) { throw null; }
-        public Microsoft.Extensions.Primitives.StringValues.Enumerator GetEnumerator() { throw null; }
-        public override int GetHashCode() { throw null; }
-        public static bool IsNullOrEmpty(Microsoft.Extensions.Primitives.StringValues value) { throw null; }
-        public static bool operator ==(Microsoft.Extensions.Primitives.StringValues left, Microsoft.Extensions.Primitives.StringValues right) { throw null; }
-        public static bool operator ==(Microsoft.Extensions.Primitives.StringValues left, object right) { throw null; }
-        public static bool operator ==(Microsoft.Extensions.Primitives.StringValues left, string right) { throw null; }
-        public static bool operator ==(Microsoft.Extensions.Primitives.StringValues left, string[] right) { throw null; }
-        public static bool operator ==(object left, Microsoft.Extensions.Primitives.StringValues right) { throw null; }
-        public static bool operator ==(string left, Microsoft.Extensions.Primitives.StringValues right) { throw null; }
-        public static bool operator ==(string[] left, Microsoft.Extensions.Primitives.StringValues right) { throw null; }
-        public static implicit operator string (Microsoft.Extensions.Primitives.StringValues values) { throw null; }
-        public static implicit operator string[] (Microsoft.Extensions.Primitives.StringValues value) { throw null; }
-        public static implicit operator Microsoft.Extensions.Primitives.StringValues (string value) { throw null; }
-        public static implicit operator Microsoft.Extensions.Primitives.StringValues (string[] values) { throw null; }
-        public static bool operator !=(Microsoft.Extensions.Primitives.StringValues left, Microsoft.Extensions.Primitives.StringValues right) { throw null; }
-        public static bool operator !=(Microsoft.Extensions.Primitives.StringValues left, object right) { throw null; }
-        public static bool operator !=(Microsoft.Extensions.Primitives.StringValues left, string right) { throw null; }
-        public static bool operator !=(Microsoft.Extensions.Primitives.StringValues left, string[] right) { throw null; }
-        public static bool operator !=(object left, Microsoft.Extensions.Primitives.StringValues right) { throw null; }
-        public static bool operator !=(string left, Microsoft.Extensions.Primitives.StringValues right) { throw null; }
-        public static bool operator !=(string[] left, Microsoft.Extensions.Primitives.StringValues right) { throw null; }
-        void System.Collections.Generic.ICollection<System.String>.Add(string item) { }
-        void System.Collections.Generic.ICollection<System.String>.Clear() { }
-        bool System.Collections.Generic.ICollection<System.String>.Contains(string item) { throw null; }
-        void System.Collections.Generic.ICollection<System.String>.CopyTo(string[] array, int arrayIndex) { }
-        bool System.Collections.Generic.ICollection<System.String>.Remove(string item) { throw null; }
-        System.Collections.Generic.IEnumerator<string> System.Collections.Generic.IEnumerable<System.String>.GetEnumerator() { throw null; }
-        int System.Collections.Generic.IList<System.String>.IndexOf(string item) { throw null; }
-        void System.Collections.Generic.IList<System.String>.Insert(int index, string item) { }
-        void System.Collections.Generic.IList<System.String>.RemoveAt(int index) { }
-        System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator() { throw null; }
-        public string[] ToArray() { throw null; }
-        public override string ToString() { throw null; }
-        [System.Runtime.InteropServices.StructLayoutAttribute(System.Runtime.InteropServices.LayoutKind.Sequential)]
-        public partial struct Enumerator : System.Collections.Generic.IEnumerator<string>, System.Collections.IEnumerator, System.IDisposable
-        {
-            private object _dummy;
-            private int _dummyPrimitive;
-            public Enumerator(ref Microsoft.Extensions.Primitives.StringValues values) { throw null; }
-            public string Current { get { throw null; } }
-            object System.Collections.IEnumerator.Current { get { throw null; } }
-            public void Dispose() { }
-            public bool MoveNext() { throw null; }
-            void System.Collections.IEnumerator.Reset() { }
-        }
-    }
-}
diff --git a/src/libraries/Microsoft.Extensions.Primitives/src/CancellationChangeToken.cs b/src/libraries/Microsoft.Extensions.Primitives/src/CancellationChangeToken.cs
index bb1a754cb4a620..1df95d5a66a74a 100644
--- a/src/libraries/Microsoft.Extensions.Primitives/src/CancellationChangeToken.cs
+++ b/src/libraries/Microsoft.Extensions.Primitives/src/CancellationChangeToken.cs
@@ -32,7 +32,7 @@ public CancellationChangeToken(CancellationToken cancellationToken)
         /// <inheritdoc />
         public IDisposable RegisterChangeCallback(Action<object> callback, object state)
         {
-#if NETCOREAPP
+#if NETCOREAPP || NETSTANDARD2_1
             try
             {
                 return Token.UnsafeRegister(callback, state);
diff --git a/src/libraries/Microsoft.Extensions.Primitives/src/Microsoft.Extensions.Primitives.csproj b/src/libraries/Microsoft.Extensions.Primitives/src/Microsoft.Extensions.Primitives.csproj
index 81dc5fe5977b79..407d76de016d8e 100644
--- a/src/libraries/Microsoft.Extensions.Primitives/src/Microsoft.Extensions.Primitives.csproj
+++ b/src/libraries/Microsoft.Extensions.Primitives/src/Microsoft.Extensions.Primitives.csproj
@@ -1,27 +1,38 @@
 <Project Sdk="Microsoft.NET.Sdk">
-
   <PropertyGroup>
-    <Description>Primitives shared by framework extensions. Commonly used types include:
-Microsoft.Extensions.Primitives.IChangeToken
-Microsoft.Extensions.Primitives.StringValues
-Microsoft.Extensions.Primitives.StringSegment</Description>
-    <TargetFrameworks>netstandard2.0;$(DefaultNetCoreTargetFramework)</TargetFrameworks>
-    <TargetFrameworks Condition="'$(DotNetBuildFromSource)' == 'true'">$(DefaultNetCoreTargetFramework)</TargetFrameworks>
-    <NoWarn>$(NoWarn);CS1591</NoWarn>
+    <TargetFrameworks>$(NetCoreAppCurrent);netcoreapp3.0;netstandard2.0</TargetFrameworks>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
-    <GenerateDocumentationFile>true</GenerateDocumentationFile>
-    <PackageTags>primitives</PackageTags>
-    <IsPackable>true</IsPackable>
-    <IsShipping>true</IsShipping>
+    <ExcludeCurrentNetCoreAppFromPackage>true</ExcludeCurrentNetCoreAppFromPackage>
   </PropertyGroup>
-
   <ItemGroup>
-    <Compile Include="$(SharedSourceRoot)HashCodeCombiner\**\*.cs" />
+    <Compile Include="$(CommonPath)Extensions\HashCodeCombiner\HashCodeCombiner.cs">
+      <Link>Common\src\Extensions\HashCodeCombiner\HashCodeCombiner.cs</Link>
+    </Compile>
+    <Compile Include="CancellationChangeToken.cs" />
+    <Compile Include="ChangeToken.cs" />
+    <Compile Include="CompositeChangeToken.cs" />
+    <Compile Include="Extensions.cs" />
+    <Compile Include="IChangeToken.cs" />
+    <Compile Include="InplaceStringBuilder.cs" />
+    <Compile Include="StringSegment.cs" />
+    <Compile Include="StringSegmentComparer.cs" />
+    <Compile Include="StringTokenizer.cs" />
+    <Compile Include="StringValues.cs" />
+    <Compile Include="ThrowHelper.cs" />
+  </ItemGroup>
+  <ItemGroup Condition="'$(TargetsNetCoreApp)' == 'true'">
+    <Reference Include="System.Resources.ResourceManager" />
+    <Reference Include="System.Runtime" />
+    <Reference Include="System.Runtime.CompilerServices.Unsafe" />
+    <Reference Include="System.Runtime.Extensions" />
+    <Reference Include="System.Collections" />
+    <Reference Include="System.Diagnostics.Debug" />
+    <Reference Include="System.Memory" />
+    <Reference Include="System.Threading" />
+    <Reference Include="System.Threading.Tasks" />
   </ItemGroup>
-
   <ItemGroup Condition="'$(TargetFramework)' == 'netstandard2.0'">
     <Reference Include="System.Memory" />
     <Reference Include="System.Runtime.CompilerServices.Unsafe" />
   </ItemGroup>
-
-</Project>
+</Project>
\ No newline at end of file
diff --git a/src/libraries/Microsoft.Extensions.Primitives/src/Resources.resx b/src/libraries/Microsoft.Extensions.Primitives/src/Resources/Strings.resx
similarity index 100%
rename from src/libraries/Microsoft.Extensions.Primitives/src/Resources.resx
rename to src/libraries/Microsoft.Extensions.Primitives/src/Resources/Strings.resx
diff --git a/src/libraries/Microsoft.Extensions.Primitives/src/StringSegment.cs b/src/libraries/Microsoft.Extensions.Primitives/src/StringSegment.cs
index 3802070637587a..68150af110c04f 100644
--- a/src/libraries/Microsoft.Extensions.Primitives/src/StringSegment.cs
+++ b/src/libraries/Microsoft.Extensions.Primitives/src/StringSegment.cs
@@ -246,9 +246,9 @@ public bool Equals(string text, StringComparison comparisonType)
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public override int GetHashCode()
         {
-#if NETCOREAPP
+#if NETCOREAPP || NETSTANDARD2_1
             return string.GetHashCode(AsSpan());
-#elif NETSTANDARD
+#elif NETSTANDARD2_0
             // This GetHashCode is expensive since it allocates on every call.
             // However this is required to ensure we retain any behavior (such as hash code randomization) that
             // string.GetHashCode has.
diff --git a/src/libraries/Microsoft.Extensions.Primitives/src/StringSegmentComparer.cs b/src/libraries/Microsoft.Extensions.Primitives/src/StringSegmentComparer.cs
index 1c4777b3ac8a8c..eaecc9efb764cf 100644
--- a/src/libraries/Microsoft.Extensions.Primitives/src/StringSegmentComparer.cs
+++ b/src/libraries/Microsoft.Extensions.Primitives/src/StringSegmentComparer.cs
@@ -28,7 +28,7 @@ public int Compare(StringSegment x, StringSegment y)
         {
             return StringSegment.Compare(x, y, Comparison);
         }
-		
+
         public bool Equals(StringSegment x, StringSegment y)
         {
             return StringSegment.Equals(x, y, Comparison);
@@ -36,7 +36,7 @@ public bool Equals(StringSegment x, StringSegment y)
 
         public int GetHashCode(StringSegment obj)
         {
-#if NETCOREAPP
+#if NETCOREAPP || NETSTANDARD2_1
             return string.GetHashCode(obj.AsSpan(), Comparison);
 #else
             if (!obj.HasValue)
diff --git a/src/libraries/Microsoft.Extensions.Primitives/src/StringValues.cs b/src/libraries/Microsoft.Extensions.Primitives/src/StringValues.cs
index 489fbbd2383f3b..5fe99cb6c188eb 100644
--- a/src/libraries/Microsoft.Extensions.Primitives/src/StringValues.cs
+++ b/src/libraries/Microsoft.Extensions.Primitives/src/StringValues.cs
@@ -219,7 +219,7 @@ static string GetJoinedStringValueFromArray(string[] values)
                         length += value.Length;
                     }
                 }
-#if NETCOREAPP
+#if NETCOREAPP || NETSTANDARD2_1
                 // Create the new string
                 return string.Create(length, values, (span, strings) => {
                     var offset = 0;
@@ -622,7 +622,6 @@ public static bool Equals(StringValues left, StringValues right)
         /// <returns><c>true</c> if the value of <paramref name="other"/> is the same as this instance; otherwise, <c>false</c>.</returns>
         public bool Equals(string[] other) => Equals(this, new StringValues(other));
 
-
         /// <inheritdoc cref="Equals(StringValues, string)" />
         public static bool operator ==(StringValues left, string right) => Equals(left, new StringValues(right));
 
diff --git a/src/libraries/Microsoft.Extensions.Primitives/src/ThrowHelper.cs b/src/libraries/Microsoft.Extensions.Primitives/src/ThrowHelper.cs
index 6556fae6e2cdfa..a3ea5ac13b59a0 100644
--- a/src/libraries/Microsoft.Extensions.Primitives/src/ThrowHelper.cs
+++ b/src/libraries/Microsoft.Extensions.Primitives/src/ThrowHelper.cs
@@ -53,7 +53,7 @@ internal static ArgumentException GetArgumentException(ExceptionResource resourc
 
         private static string GetResourceText(ExceptionResource resource)
         {
-            return Resources.ResourceManager.GetString(GetResourceName(resource), Resources.Culture);
+            return SR.GetResourceString(GetResourceName(resource));
         }
 
         private static string GetArgumentName(ExceptionArgument argument)
diff --git a/src/libraries/Microsoft.Extensions.Primitives/tests/Microsoft.Extensions.Primitives.Tests.csproj b/src/libraries/Microsoft.Extensions.Primitives/tests/Microsoft.Extensions.Primitives.Tests.csproj
index 8dc0ca80baf58d..44baa5385bd42c 100644
--- a/src/libraries/Microsoft.Extensions.Primitives/tests/Microsoft.Extensions.Primitives.Tests.csproj
+++ b/src/libraries/Microsoft.Extensions.Primitives/tests/Microsoft.Extensions.Primitives.Tests.csproj
@@ -4,6 +4,19 @@
     <TargetFrameworks>$(DefaultNetCoreTargetFramework);net472</TargetFrameworks>
   </PropertyGroup>
 
+  <ItemGroup>
+    <Compile Include="ChangeTokenTest.cs" />
+    <Compile Include="CompositeChangeTokenTest.cs" />
+    <Compile Include="InplaceStringBuilderTest.cs" />
+    <Compile Include="StringSegmentTest.cs" />
+    <Compile Include="StringTokenizerTest.cs" />
+    <Compile Include="StringValuesTests.cs" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Moq" Version="$(MoqVersion)" />
+  </ItemGroup>
+  
   <ItemGroup>
     <Reference Include="Microsoft.Extensions.Primitives" />
   </ItemGroup>
diff --git a/src/libraries/pkg/baseline/packageIndex.json b/src/libraries/pkg/baseline/packageIndex.json
index dbf70e5c32f096..19d9a7039dc49c 100644
--- a/src/libraries/pkg/baseline/packageIndex.json
+++ b/src/libraries/pkg/baseline/packageIndex.json
@@ -145,6 +145,28 @@
         "5.0.0.0": "5.0.0"
       }
     },
+    "Microsoft.Extensions.Primitives": {
+      "StableVersions": [
+        "1.0.0",
+        "1.0.1",
+        "1.1.0",
+        "1.1.1",
+        "2.0.0",
+        "2.1.0",
+        "2.1.1",
+        "2.1.6",
+        "2.2.0",
+        "3.0.0",
+        "3.0.1",
+        "3.0.2",
+        "3.1.0",
+        "3.1.1"
+      ],
+      "InboxOn": {},
+      "AssemblyVersionInPackageVersion": {
+        "5.0.0.0": "5.0.0"
+      }
+    },
     "Microsoft.IO.Redist": {
       "StableVersions": [
         "4.6.0"
diff --git a/src/libraries/pkg/descriptions.json b/src/libraries/pkg/descriptions.json
index 2fcc2a383465e2..9c10db8a8bcfec 100644
--- a/src/libraries/pkg/descriptions.json
+++ b/src/libraries/pkg/descriptions.json
@@ -14,6 +14,15 @@
     "Description": "Provides a portable version of the Microsoft.Cci library",
     "CommonTypes": []
   },
+  {
+    "Name": "Microsoft.Extensions.Primitives",
+    "Description": "Primitives shared by framework extensions. Commonly used types include:",
+    "CommonTypes": [
+      "Microsoft.Extensions.Primitives.IChangeToken",
+      "Microsoft.Extensions.Primitives.StringValues",
+      "Microsoft.Extensions.Primitives.StringSegment"
+    ]
+  },
   {
     "Name": "Microsoft.Bcl.HashCode",
     "Description": "Provides the HashCode type for .NET Standard 2.0. This package is not required starting with .NET Standard 2.1 and .NET Core 3.0.",