From e99a0271777a146b7040174b9bd1a2a9bb6ea9a0 Mon Sep 17 00:00:00 2001
From: Matt Kotsenas <matt.kotsenas@gmail.com>
Date: Fri, 12 Sep 2025 16:49:26 -0700
Subject: [PATCH 1/4] Add codes to existing warnings

---
 README.md                                     |  4 ++--
 {Documentation => docs}/README.md             |  0
 .../Reproducible-MSBuild/Organization.md      |  0
 .../Reproducible-MSBuild/README.md            |  0
 .../Reproducible-MSBuild/References.md        |  0
 .../Techniques/AssemblySearchPaths.md         |  0
 .../Techniques/DOTNET_MULTILEVEL_LOOKUP.md    |  0
 .../DisableImplicitLibraryPacksFolder.md      |  0
 .../DisableImplicitNuGetFallbackFolder.md     |  0
 .../Techniques/NUGET_XMLDOC_MODE.md           |  0
 .../Techniques/NetCoreTargetingPackRoot.md    |  0
 .../Techniques/TargetFrameworkRootPath.md     |  0
 .../Reproducible-MSBuild/Techniques/toc.md    |  0
 docs/diagnostics/RPB0001.md                   | 20 ++++++++++++++++
 docs/diagnostics/RPB0002.md                   | 24 +++++++++++++++++++
 .../Sdk/Sdk.props                             |  6 +++--
 .../DotNet.ReproducibleBuilds.targets         |  5 +++-
 17 files changed, 54 insertions(+), 5 deletions(-)
 rename {Documentation => docs}/README.md (100%)
 rename {Documentation => docs}/Reproducible-MSBuild/Organization.md (100%)
 rename {Documentation => docs}/Reproducible-MSBuild/README.md (100%)
 rename {Documentation => docs}/Reproducible-MSBuild/References.md (100%)
 rename {Documentation => docs}/Reproducible-MSBuild/Techniques/AssemblySearchPaths.md (100%)
 rename {Documentation => docs}/Reproducible-MSBuild/Techniques/DOTNET_MULTILEVEL_LOOKUP.md (100%)
 rename {Documentation => docs}/Reproducible-MSBuild/Techniques/DisableImplicitLibraryPacksFolder.md (100%)
 rename {Documentation => docs}/Reproducible-MSBuild/Techniques/DisableImplicitNuGetFallbackFolder.md (100%)
 rename {Documentation => docs}/Reproducible-MSBuild/Techniques/NUGET_XMLDOC_MODE.md (100%)
 rename {Documentation => docs}/Reproducible-MSBuild/Techniques/NetCoreTargetingPackRoot.md (100%)
 rename {Documentation => docs}/Reproducible-MSBuild/Techniques/TargetFrameworkRootPath.md (100%)
 rename {Documentation => docs}/Reproducible-MSBuild/Techniques/toc.md (100%)
 create mode 100644 docs/diagnostics/RPB0001.md
 create mode 100644 docs/diagnostics/RPB0002.md

diff --git a/README.md b/README.md
index 2761d81..ad95148 100644
--- a/README.md
+++ b/README.md
@@ -39,13 +39,13 @@ if you're using a lower version.
 Prerelease packages are available on the following [NuGet feed](https://dev.azure.com/dotnet/Projects/_packaging?_a=feed&feed=ReproducibleBuilds):
 `https://pkgs.dev.azure.com/dotnet/Projects/_packaging/ReproducibleBuilds/nuget/v3/index.json`
 
-## DotNet.ReproducibleBuilds.Isolated Documentation and nuget package
+## DotNet.ReproducibleBuilds.Isolated documentation and nuget package
 
 [![NuGet Version](https://img.shields.io/nuget/v/DotNet.ReproducibleBuilds.Isolated?style=flat&label=DotNet.ReproducibleBuilds.Isolated)](https://www.nuget.org/packages/DotNet.ReproducibleBuilds.Isolated)
 [![NuGet Downloads](https://img.shields.io/nuget/dt/DotNet.ReproducibleBuilds.Isolated?style=flat)](https://www.nuget.org/packages/DotNet.ReproducibleBuilds.Isolated)
 
 It's highly recommended that all projects enable these settings, either via 
-adding this package or manually, as described in [Documentation/Reproducible-MSBuild](Documentation/Reproducible-MSBuild/README.md).
+adding this package or manually, as described in [docs/Reproducible-MSBuild](docs/Reproducible-MSBuild/README.md).
 
 This package configures a variety of properties and item groups to prevent your build from unintentionally 
 depending on other installed software that's not described by your repo. All build dependencies should come
diff --git a/Documentation/README.md b/docs/README.md
similarity index 100%
rename from Documentation/README.md
rename to docs/README.md
diff --git a/Documentation/Reproducible-MSBuild/Organization.md b/docs/Reproducible-MSBuild/Organization.md
similarity index 100%
rename from Documentation/Reproducible-MSBuild/Organization.md
rename to docs/Reproducible-MSBuild/Organization.md
diff --git a/Documentation/Reproducible-MSBuild/README.md b/docs/Reproducible-MSBuild/README.md
similarity index 100%
rename from Documentation/Reproducible-MSBuild/README.md
rename to docs/Reproducible-MSBuild/README.md
diff --git a/Documentation/Reproducible-MSBuild/References.md b/docs/Reproducible-MSBuild/References.md
similarity index 100%
rename from Documentation/Reproducible-MSBuild/References.md
rename to docs/Reproducible-MSBuild/References.md
diff --git a/Documentation/Reproducible-MSBuild/Techniques/AssemblySearchPaths.md b/docs/Reproducible-MSBuild/Techniques/AssemblySearchPaths.md
similarity index 100%
rename from Documentation/Reproducible-MSBuild/Techniques/AssemblySearchPaths.md
rename to docs/Reproducible-MSBuild/Techniques/AssemblySearchPaths.md
diff --git a/Documentation/Reproducible-MSBuild/Techniques/DOTNET_MULTILEVEL_LOOKUP.md b/docs/Reproducible-MSBuild/Techniques/DOTNET_MULTILEVEL_LOOKUP.md
similarity index 100%
rename from Documentation/Reproducible-MSBuild/Techniques/DOTNET_MULTILEVEL_LOOKUP.md
rename to docs/Reproducible-MSBuild/Techniques/DOTNET_MULTILEVEL_LOOKUP.md
diff --git a/Documentation/Reproducible-MSBuild/Techniques/DisableImplicitLibraryPacksFolder.md b/docs/Reproducible-MSBuild/Techniques/DisableImplicitLibraryPacksFolder.md
similarity index 100%
rename from Documentation/Reproducible-MSBuild/Techniques/DisableImplicitLibraryPacksFolder.md
rename to docs/Reproducible-MSBuild/Techniques/DisableImplicitLibraryPacksFolder.md
diff --git a/Documentation/Reproducible-MSBuild/Techniques/DisableImplicitNuGetFallbackFolder.md b/docs/Reproducible-MSBuild/Techniques/DisableImplicitNuGetFallbackFolder.md
similarity index 100%
rename from Documentation/Reproducible-MSBuild/Techniques/DisableImplicitNuGetFallbackFolder.md
rename to docs/Reproducible-MSBuild/Techniques/DisableImplicitNuGetFallbackFolder.md
diff --git a/Documentation/Reproducible-MSBuild/Techniques/NUGET_XMLDOC_MODE.md b/docs/Reproducible-MSBuild/Techniques/NUGET_XMLDOC_MODE.md
similarity index 100%
rename from Documentation/Reproducible-MSBuild/Techniques/NUGET_XMLDOC_MODE.md
rename to docs/Reproducible-MSBuild/Techniques/NUGET_XMLDOC_MODE.md
diff --git a/Documentation/Reproducible-MSBuild/Techniques/NetCoreTargetingPackRoot.md b/docs/Reproducible-MSBuild/Techniques/NetCoreTargetingPackRoot.md
similarity index 100%
rename from Documentation/Reproducible-MSBuild/Techniques/NetCoreTargetingPackRoot.md
rename to docs/Reproducible-MSBuild/Techniques/NetCoreTargetingPackRoot.md
diff --git a/Documentation/Reproducible-MSBuild/Techniques/TargetFrameworkRootPath.md b/docs/Reproducible-MSBuild/Techniques/TargetFrameworkRootPath.md
similarity index 100%
rename from Documentation/Reproducible-MSBuild/Techniques/TargetFrameworkRootPath.md
rename to docs/Reproducible-MSBuild/Techniques/TargetFrameworkRootPath.md
diff --git a/Documentation/Reproducible-MSBuild/Techniques/toc.md b/docs/Reproducible-MSBuild/Techniques/toc.md
similarity index 100%
rename from Documentation/Reproducible-MSBuild/Techniques/toc.md
rename to docs/Reproducible-MSBuild/Techniques/toc.md
diff --git a/docs/diagnostics/RPB0001.md b/docs/diagnostics/RPB0001.md
new file mode 100644
index 0000000..9293aaa
--- /dev/null
+++ b/docs/diagnostics/RPB0001.md
@@ -0,0 +1,20 @@
+# RPB0001: DotNet.ReproducibleBuilds minimum required MSBuild version
+
+## Description
+
+This warning occurs when the project is using an MSBuild version that is older than the minimum required version for
+this package.
+
+## Cause
+
+The DotNet.ReproducibleBuilds package requires specific MSBuild features that were introduced in newer versions. Older
+versions of MSBuild lack the necessary functionality to ensure reproducible builds.
+
+## Resolution
+
+To resolve this warning, update your development environment to use a supported version.
+
+## Related Documentation
+
+- [Upgrade to a new .NET version](https://learn.microsoft.com/en-us/dotnet/core/install/upgrade)
+- [.NET SDK, MSBuild, and Visual Studio versioning](https://learn.microsoft.com/en-us/dotnet/core/porting/versioning-sdk-msbuild-vs)
diff --git a/docs/diagnostics/RPB0002.md b/docs/diagnostics/RPB0002.md
new file mode 100644
index 0000000..dc706c3
--- /dev/null
+++ b/docs/diagnostics/RPB0002.md
@@ -0,0 +1,24 @@
+# RPB0002: TargetFrameworkRootPath not initialized
+
+## Description
+
+This warning occurs when building .NET Framework projects without proper reference assembly configuration.
+The `TargetFrameworkRootPath` property is undefined, which prevents the build system from locating the correct
+.NET Framework reference assemblies.
+
+## Cause
+
+This warning appears when:
+- Building a .NET Framework project (e.g., net462, net48)
+- The `TargetFrameworkRootPath` MSBuild property is not properly set
+- The `Microsoft.NETFramework.ReferenceAssemblies` NuGet package is not referenced
+
+## Resolution
+
+See [Build apps against Microsoft.NETFramework.ReferenceAssemblies](https://learn.microsoft.com/en-us/dotnet/framework/migration-guide/reference-assemblies)
+
+## Related Documentation
+
+- [Microsoft.NETFramework.ReferenceAssemblies Package](https://www.nuget.org/packages/Microsoft.NETFramework.ReferenceAssemblies/)
+- [Build apps against Microsoft.NETFramework.ReferenceAssemblies](https://learn.microsoft.com/en-us/dotnet/framework/migration-guide/reference-assemblies)
+- [Techniques/TargetFrameworkRootPath](../Reproducible-MSBuild/Techniques/TargetFrameworkRootPath.md)
\ No newline at end of file
diff --git a/src/DotNet.ReproducibleBuilds.Isolated/Sdk/Sdk.props b/src/DotNet.ReproducibleBuilds.Isolated/Sdk/Sdk.props
index 54587c5..5652709 100644
--- a/src/DotNet.ReproducibleBuilds.Isolated/Sdk/Sdk.props
+++ b/src/DotNet.ReproducibleBuilds.Isolated/Sdk/Sdk.props
@@ -2,8 +2,8 @@
   <!--
     Isolate the build from unrelated installed software.
 
-    Each of these settings and rationale are detailed in the Documentation that can be found
-    at https://github.com/dotnet/reproducible-builds/blob/main/Documentation/Reproducible-MSBuild/Techniques/toc.md
+    Each of these settings and rationale are detailed in the documentation that can be found
+    at https://github.com/dotnet/reproducible-builds/blob/main/docs/Reproducible-MSBuild/Techniques/toc.md
   -->
 
   <!--
@@ -32,6 +32,8 @@
     <Message Text="TargetFrameworkVersion=$(TargetFrameworkVersion)" />
     <Warning
       Condition="'$(TargetFrameworkRootPath)' == '[UNDEFINED]' and '$(TargetFrameworkIdentifier)' == '.NETFramework'"
+      Code="RPB0002"
+      HelpLink="https://github.com/dotnet/reproducible-builds/blob/main/docs/diagnostics/RPB0002.md"
       Text="Error, TargetFrameworkRootPath not initialized. If you're building for net462 or any other version of desktop NETFramework, please reference the 'Microsoft.NETFramework.ReferenceAssemblies' nuget package and run restore on the project to fix up your framework reference paths." />
   </Target>
 
diff --git a/src/DotNet.ReproducibleBuilds/DotNet.ReproducibleBuilds.targets b/src/DotNet.ReproducibleBuilds/DotNet.ReproducibleBuilds.targets
index 7f501da..7d09a01 100644
--- a/src/DotNet.ReproducibleBuilds/DotNet.ReproducibleBuilds.targets
+++ b/src/DotNet.ReproducibleBuilds/DotNet.ReproducibleBuilds.targets
@@ -41,6 +41,9 @@
   <Target Name="_ReproducibleBuildsMSBuildVersionCheck"
     Condition="$([MSBuild]::VersionLessThan($(_ReproducibleBuildsMSBuildVersion), $(_ReproducibleBuildsMSBuildMinVersion)))"
     BeforeTargets="ResolveAssemblyReferences;Build;Rebuild">
-    <Warning Text="Reproducible builds requires MSBuild '$(_ReproducibleBuildsMSBuildMinVersion)' or later. This project is using '$(_ReproducibleBuildsMSBuildVersion)'. Use .NET SDK 8.0.100 or VS 17.8 or later." />
+    <Warning
+      Code="RPB0001"
+      HelpLink="https://github.com/dotnet/reproducible-builds/blob/main/docs/diagnostics/RPB0001.md"
+      Text="DotNet.ReproducibleBuilds requires MSBuild '$(_ReproducibleBuildsMSBuildMinVersion)' or later. This project is using '$(_ReproducibleBuildsMSBuildVersion)'. Use .NET SDK 8.0.100 or VS 17.8 or later." />
   </Target>
 </Project>
\ No newline at end of file

From 84af7d9bf358c1ac58e7ff4b07f6f4cd38e7d6f3 Mon Sep 17 00:00:00 2001
From: Matt Kotsenas <matt.kotsenas@gmail.com>
Date: Mon, 15 Sep 2025 10:48:14 -0700
Subject: [PATCH 2/4] Add suppression tests

---
 .../MinimumVersionTests.cs                    | 25 +++++++++++++------
 1 file changed, 17 insertions(+), 8 deletions(-)

diff --git a/tests/DotNet.ReproducibleBuilds.Tests/MinimumVersionTests.cs b/tests/DotNet.ReproducibleBuilds.Tests/MinimumVersionTests.cs
index 964dba1..4ec0c9a 100644
--- a/tests/DotNet.ReproducibleBuilds.Tests/MinimumVersionTests.cs
+++ b/tests/DotNet.ReproducibleBuilds.Tests/MinimumVersionTests.cs
@@ -6,21 +6,30 @@ namespace DotNet.ReproducibleBuilds.Tests;
 public class MinimumVersionTests : TestBase
 {
     [Theory]
-    [InlineData("17.7.0", false)]
-    [InlineData("17.8.0", true)]
-    [InlineData("17.9.0", true)]
-    public void BelowMinimumVersionEmitsWarning(string msbuildVersion, bool success)
+    [InlineData("17.7.0", false, false)]
+    [InlineData("17.7.0", false, true)]
+    [InlineData("17.8.0", true, false)]
+    [InlineData("17.9.0", true, true)]
+    public void BelowMinimumVersionEmitsWarning(string msbuildVersion, bool success, bool suppress)
     {
         Dictionary<string, string> globalProperties = new()
         {
             ["_ReproducibleBuildsMSBuildVersion"] = msbuildVersion
         };
 
-        ProjectCreator.Templates
-            .ReproducibleBuildProject(GetRandomFile(".csproj"))
-            .TryBuild(restore: false, target: "_ReproducibleBuildsMSBuildVersionCheck", globalProperties, out bool result, out BuildOutput output);
+        ProjectCreator project = ProjectCreator.Templates
+            .ReproducibleBuildProject(GetRandomFile(".csproj"));
+
+        if (suppress)
+        {
+            project.Property("NoWarn", "RPB0001"); // Suppress the RPB0001 warning
+        }
+
+        project.TryBuild(restore: false, target: "_ReproducibleBuildsMSBuildVersionCheck", globalProperties, out bool result, out BuildOutput output);
+
+        int expected = (success || suppress) ? 0 : 1;
 
         result.Should().BeTrue();
-        output.Warnings.Should().HaveCount(success ? 0 : 1);
+        output.Warnings.Should().HaveCount(expected);
     }
 }

From a612283291413151933423a73023492030233c13 Mon Sep 17 00:00:00 2001
From: Matt Kotsenas <matt.kotsenas@gmail.com>
Date: Mon, 15 Sep 2025 11:18:36 -0700
Subject: [PATCH 3/4] Create Shared folder between tests

---
 .../ContinuousIntegrationTests.cs                             | 4 +++-
 .../DotNet.ReproducibleBuilds.Tests.csproj                    | 1 +
 tests/DotNet.ReproducibleBuilds.Tests/MinimumVersionTests.cs  | 4 +++-
 tests/DotNet.ReproducibleBuilds.Tests/ProjectTemplates.cs     | 4 +++-
 tests/DotNet.ReproducibleBuilds.Tests/SourceLinkTests.cs      | 4 +++-
 .../BooleanExtensions.cs                                      | 2 +-
 .../CollectionExtensions.cs                                   | 2 +-
 .../DictionaryExtensions.cs                                   | 2 +-
 .../DisposableCollection.cs                                   | 2 +-
 .../EnvironmentVariableSuppressor.cs                          | 2 +-
 .../FileSystemInfoExtensions.cs                               | 2 +-
 .../ProjectCreatorExtensions.cs                               | 2 +-
 tests/{DotNet.ReproducibleBuilds.Tests => Shared}/TestBase.cs | 2 +-
 13 files changed, 21 insertions(+), 12 deletions(-)
 rename tests/{DotNet.ReproducibleBuilds.Tests => Shared}/BooleanExtensions.cs (86%)
 rename tests/{DotNet.ReproducibleBuilds.Tests => Shared}/CollectionExtensions.cs (76%)
 rename tests/{DotNet.ReproducibleBuilds.Tests => Shared}/DictionaryExtensions.cs (83%)
 rename tests/{DotNet.ReproducibleBuilds.Tests => Shared}/DisposableCollection.cs (89%)
 rename tests/{DotNet.ReproducibleBuilds.Tests => Shared}/EnvironmentVariableSuppressor.cs (89%)
 rename tests/{DotNet.ReproducibleBuilds.Tests => Shared}/FileSystemInfoExtensions.cs (79%)
 rename tests/{DotNet.ReproducibleBuilds.Tests => Shared}/ProjectCreatorExtensions.cs (93%)
 rename tests/{DotNet.ReproducibleBuilds.Tests => Shared}/TestBase.cs (94%)

diff --git a/tests/DotNet.ReproducibleBuilds.Tests/ContinuousIntegrationTests.cs b/tests/DotNet.ReproducibleBuilds.Tests/ContinuousIntegrationTests.cs
index 2dc1260..a503914 100644
--- a/tests/DotNet.ReproducibleBuilds.Tests/ContinuousIntegrationTests.cs
+++ b/tests/DotNet.ReproducibleBuilds.Tests/ContinuousIntegrationTests.cs
@@ -1,4 +1,6 @@
-using FluentAssertions;
+using DotNet.ReproducibleBuilds.Tests.Shared;
+
+using FluentAssertions;
 using Microsoft.Build.Utilities.ProjectCreation;
 
 namespace DotNet.ReproducibleBuilds.Tests;
diff --git a/tests/DotNet.ReproducibleBuilds.Tests/DotNet.ReproducibleBuilds.Tests.csproj b/tests/DotNet.ReproducibleBuilds.Tests/DotNet.ReproducibleBuilds.Tests.csproj
index 184f79a..b5d349d 100644
--- a/tests/DotNet.ReproducibleBuilds.Tests/DotNet.ReproducibleBuilds.Tests.csproj
+++ b/tests/DotNet.ReproducibleBuilds.Tests/DotNet.ReproducibleBuilds.Tests.csproj
@@ -30,6 +30,7 @@
   </ItemGroup>
 
   <ItemGroup>
+    <Compile Include="../Shared/*.cs" LinkBase="Shared" />
     <None Include="$(RepoRoot)/src/DotNet.ReproducibleBuilds/*.props" CopyToOutputDirectory="PreserveNewest" />
     <None Include="$(RepoRoot)/src/DotNet.ReproducibleBuilds/*.targets" CopyToOutputDirectory="PreserveNewest" />
   </ItemGroup>
diff --git a/tests/DotNet.ReproducibleBuilds.Tests/MinimumVersionTests.cs b/tests/DotNet.ReproducibleBuilds.Tests/MinimumVersionTests.cs
index 4ec0c9a..8ff3799 100644
--- a/tests/DotNet.ReproducibleBuilds.Tests/MinimumVersionTests.cs
+++ b/tests/DotNet.ReproducibleBuilds.Tests/MinimumVersionTests.cs
@@ -1,4 +1,6 @@
-using FluentAssertions;
+using DotNet.ReproducibleBuilds.Tests.Shared;
+
+using FluentAssertions;
 using Microsoft.Build.Utilities.ProjectCreation;
 
 namespace DotNet.ReproducibleBuilds.Tests;
diff --git a/tests/DotNet.ReproducibleBuilds.Tests/ProjectTemplates.cs b/tests/DotNet.ReproducibleBuilds.Tests/ProjectTemplates.cs
index afa8d85..a3695b7 100644
--- a/tests/DotNet.ReproducibleBuilds.Tests/ProjectTemplates.cs
+++ b/tests/DotNet.ReproducibleBuilds.Tests/ProjectTemplates.cs
@@ -1,4 +1,6 @@
-using Microsoft.Build.Evaluation;
+using DotNet.ReproducibleBuilds.Tests.Shared;
+
+using Microsoft.Build.Evaluation;
 using Microsoft.Build.Utilities.ProjectCreation;
 
 namespace DotNet.ReproducibleBuilds.Tests;
diff --git a/tests/DotNet.ReproducibleBuilds.Tests/SourceLinkTests.cs b/tests/DotNet.ReproducibleBuilds.Tests/SourceLinkTests.cs
index f95f68b..725aec5 100644
--- a/tests/DotNet.ReproducibleBuilds.Tests/SourceLinkTests.cs
+++ b/tests/DotNet.ReproducibleBuilds.Tests/SourceLinkTests.cs
@@ -1,4 +1,6 @@
-using FluentAssertions;
+using DotNet.ReproducibleBuilds.Tests.Shared;
+
+using FluentAssertions;
 using Microsoft.Build.Utilities.ProjectCreation;
 
 namespace DotNet.ReproducibleBuilds.Tests;
diff --git a/tests/DotNet.ReproducibleBuilds.Tests/BooleanExtensions.cs b/tests/Shared/BooleanExtensions.cs
similarity index 86%
rename from tests/DotNet.ReproducibleBuilds.Tests/BooleanExtensions.cs
rename to tests/Shared/BooleanExtensions.cs
index 05a2bf6..4924ebb 100644
--- a/tests/DotNet.ReproducibleBuilds.Tests/BooleanExtensions.cs
+++ b/tests/Shared/BooleanExtensions.cs
@@ -1,6 +1,6 @@
 using System.Diagnostics.CodeAnalysis;
 
-namespace DotNet.ReproducibleBuilds.Tests;
+namespace DotNet.ReproducibleBuilds.Tests.Shared;
 
 internal static class BooleanExtensions
 {
diff --git a/tests/DotNet.ReproducibleBuilds.Tests/CollectionExtensions.cs b/tests/Shared/CollectionExtensions.cs
similarity index 76%
rename from tests/DotNet.ReproducibleBuilds.Tests/CollectionExtensions.cs
rename to tests/Shared/CollectionExtensions.cs
index 404b0f0..9d1c3f4 100644
--- a/tests/DotNet.ReproducibleBuilds.Tests/CollectionExtensions.cs
+++ b/tests/Shared/CollectionExtensions.cs
@@ -1,4 +1,4 @@
-namespace DotNet.ReproducibleBuilds.Tests;
+namespace DotNet.ReproducibleBuilds.Tests.Shared;
 
 internal static class CollectionExtensions
 {
diff --git a/tests/DotNet.ReproducibleBuilds.Tests/DictionaryExtensions.cs b/tests/Shared/DictionaryExtensions.cs
similarity index 83%
rename from tests/DotNet.ReproducibleBuilds.Tests/DictionaryExtensions.cs
rename to tests/Shared/DictionaryExtensions.cs
index d5b9919..c39aaff 100644
--- a/tests/DotNet.ReproducibleBuilds.Tests/DictionaryExtensions.cs
+++ b/tests/Shared/DictionaryExtensions.cs
@@ -1,4 +1,4 @@
-namespace DotNet.ReproducibleBuilds.Tests;
+namespace DotNet.ReproducibleBuilds.Tests.Shared;
 
 internal static class DictionaryExtensions
 {
diff --git a/tests/DotNet.ReproducibleBuilds.Tests/DisposableCollection.cs b/tests/Shared/DisposableCollection.cs
similarity index 89%
rename from tests/DotNet.ReproducibleBuilds.Tests/DisposableCollection.cs
rename to tests/Shared/DisposableCollection.cs
index 5da02cf..86264bc 100644
--- a/tests/DotNet.ReproducibleBuilds.Tests/DisposableCollection.cs
+++ b/tests/Shared/DisposableCollection.cs
@@ -1,4 +1,4 @@
-namespace DotNet.ReproducibleBuilds.Tests;
+namespace DotNet.ReproducibleBuilds.Tests.Shared;
 
 internal sealed class DisposableCollection : IDisposable
 {
diff --git a/tests/DotNet.ReproducibleBuilds.Tests/EnvironmentVariableSuppressor.cs b/tests/Shared/EnvironmentVariableSuppressor.cs
similarity index 89%
rename from tests/DotNet.ReproducibleBuilds.Tests/EnvironmentVariableSuppressor.cs
rename to tests/Shared/EnvironmentVariableSuppressor.cs
index 0f62f24..73a92d4 100644
--- a/tests/DotNet.ReproducibleBuilds.Tests/EnvironmentVariableSuppressor.cs
+++ b/tests/Shared/EnvironmentVariableSuppressor.cs
@@ -1,4 +1,4 @@
-namespace DotNet.ReproducibleBuilds.Tests;
+namespace DotNet.ReproducibleBuilds.Tests.Shared;
 
 internal sealed class EnvironmentVariableSuppressor : IDisposable
 {
diff --git a/tests/DotNet.ReproducibleBuilds.Tests/FileSystemInfoExtensions.cs b/tests/Shared/FileSystemInfoExtensions.cs
similarity index 79%
rename from tests/DotNet.ReproducibleBuilds.Tests/FileSystemInfoExtensions.cs
rename to tests/Shared/FileSystemInfoExtensions.cs
index 7abcbb7..993b8f3 100644
--- a/tests/DotNet.ReproducibleBuilds.Tests/FileSystemInfoExtensions.cs
+++ b/tests/Shared/FileSystemInfoExtensions.cs
@@ -1,4 +1,4 @@
-namespace DotNet.ReproducibleBuilds.Tests;
+namespace DotNet.ReproducibleBuilds.Tests.Shared;
 
 internal static class FileSystemInfoExtensions
 {
diff --git a/tests/DotNet.ReproducibleBuilds.Tests/ProjectCreatorExtensions.cs b/tests/Shared/ProjectCreatorExtensions.cs
similarity index 93%
rename from tests/DotNet.ReproducibleBuilds.Tests/ProjectCreatorExtensions.cs
rename to tests/Shared/ProjectCreatorExtensions.cs
index 9d27a14..dca3199 100644
--- a/tests/DotNet.ReproducibleBuilds.Tests/ProjectCreatorExtensions.cs
+++ b/tests/Shared/ProjectCreatorExtensions.cs
@@ -1,7 +1,7 @@
 using Microsoft.Build.Evaluation;
 using Microsoft.Build.Utilities.ProjectCreation;
 
-namespace DotNet.ReproducibleBuilds.Tests;
+namespace DotNet.ReproducibleBuilds.Tests.Shared;
 
 internal static class ProjectCreatorExtensions
 {
diff --git a/tests/DotNet.ReproducibleBuilds.Tests/TestBase.cs b/tests/Shared/TestBase.cs
similarity index 94%
rename from tests/DotNet.ReproducibleBuilds.Tests/TestBase.cs
rename to tests/Shared/TestBase.cs
index b1599f4..9da4a54 100644
--- a/tests/DotNet.ReproducibleBuilds.Tests/TestBase.cs
+++ b/tests/Shared/TestBase.cs
@@ -1,4 +1,4 @@
-namespace DotNet.ReproducibleBuilds.Tests;
+namespace DotNet.ReproducibleBuilds.Tests.Shared;
 
 public abstract class TestBase : IDisposable
 {

From 202ad55b8df8d96a1a3e3cfdd0f4dd2deeb29b6c Mon Sep 17 00:00:00 2001
From: Matt Kotsenas <matt.kotsenas@gmail.com>
Date: Mon, 15 Sep 2025 11:48:22 -0700
Subject: [PATCH 4/4] Add suppression tests

---
 ...t.ReproducibleBuilds.Isolated.Tests.csproj | 42 +++++++++++++++++++
 .../MSBuildModuleInitializer.cs               | 13 ++++++
 .../ProjectTemplates.cs                       | 24 +++++++++++
 .../TargetFrameworkRootPathTests.cs           | 34 +++++++++++++++
 4 files changed, 113 insertions(+)
 create mode 100644 tests/DotNet.ReproducibleBuilds.Isolated.Tests/DotNet.ReproducibleBuilds.Isolated.Tests.csproj
 create mode 100644 tests/DotNet.ReproducibleBuilds.Isolated.Tests/MSBuildModuleInitializer.cs
 create mode 100644 tests/DotNet.ReproducibleBuilds.Isolated.Tests/ProjectTemplates.cs
 create mode 100644 tests/DotNet.ReproducibleBuilds.Isolated.Tests/TargetFrameworkRootPathTests.cs

diff --git a/tests/DotNet.ReproducibleBuilds.Isolated.Tests/DotNet.ReproducibleBuilds.Isolated.Tests.csproj b/tests/DotNet.ReproducibleBuilds.Isolated.Tests/DotNet.ReproducibleBuilds.Isolated.Tests.csproj
new file mode 100644
index 0000000..05fcabc
--- /dev/null
+++ b/tests/DotNet.ReproducibleBuilds.Isolated.Tests/DotNet.ReproducibleBuilds.Isolated.Tests.csproj
@@ -0,0 +1,42 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFrameworks>net472;net8.0;net9.0;net10.0</TargetFrameworks>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+    <LangVersion>latest</LangVersion>
+    <OutputType>Exe</OutputType>
+
+    <IsTestProject>true</IsTestProject>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="coverlet.collector">
+      <PrivateAssets>all</PrivateAssets>
+      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+    </PackageReference>
+    <PackageReference Include="FluentAssertions" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" />
+    <PackageReference Include="MSBuild.ProjectCreation" />
+    <PackageReference Include="xunit.v3" />
+    <PackageReference Include="xunit.runner.visualstudio">
+      <PrivateAssets>all</PrivateAssets>
+      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+    </PackageReference>
+    <PackageReference Include="Polyfill">
+      <PrivateAssets>all</PrivateAssets>
+      <IncludeAssets>runtime; build; native; contentfiles; analyzers</IncludeAssets>
+    </PackageReference>
+  </ItemGroup>
+
+  <ItemGroup>
+    <Compile Include="../Shared/*.cs" LinkBase="Shared" />
+    <None Include="$(RepoRoot)/src/DotNet.ReproducibleBuilds.Isolated/Sdk/*.props" CopyToOutputDirectory="PreserveNewest" />
+    <None Include="$(RepoRoot)/src/DotNet.ReproducibleBuilds.Isolated/Sdk/*.targets" CopyToOutputDirectory="PreserveNewest" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <Using Include="Xunit" />
+  </ItemGroup>
+
+</Project>
diff --git a/tests/DotNet.ReproducibleBuilds.Isolated.Tests/MSBuildModuleInitializer.cs b/tests/DotNet.ReproducibleBuilds.Isolated.Tests/MSBuildModuleInitializer.cs
new file mode 100644
index 0000000..a42a8fe
--- /dev/null
+++ b/tests/DotNet.ReproducibleBuilds.Isolated.Tests/MSBuildModuleInitializer.cs
@@ -0,0 +1,13 @@
+using Microsoft.Build.Utilities.ProjectCreation;
+using System.Runtime.CompilerServices;
+
+namespace DotNet.ReproducibleBuilds.Isolated.Tests;
+
+internal static class MSBuildModuleInitializer
+{
+    [ModuleInitializer]
+    internal static void InitializeMSBuild()
+    {
+        MSBuildAssemblyResolver.Register();
+    }
+}
diff --git a/tests/DotNet.ReproducibleBuilds.Isolated.Tests/ProjectTemplates.cs b/tests/DotNet.ReproducibleBuilds.Isolated.Tests/ProjectTemplates.cs
new file mode 100644
index 0000000..5f205e8
--- /dev/null
+++ b/tests/DotNet.ReproducibleBuilds.Isolated.Tests/ProjectTemplates.cs
@@ -0,0 +1,24 @@
+using DotNet.ReproducibleBuilds.Tests.Shared;
+
+using Microsoft.Build.Evaluation;
+using Microsoft.Build.Utilities.ProjectCreation;
+
+namespace DotNet.ReproducibleBuilds.Isolated.Tests;
+
+internal static class ProjectTemplates
+{
+    private static readonly string ThisAssemblyDirectory = Path.GetDirectoryName(typeof(ProjectTemplates).Assembly.Location)!;
+
+    public static ProjectCreator ReproducibleBuildsIsolatedProject(this ProjectCreatorTemplates templates, FileInfo project, Action<ProjectCreator>? configureProject = null)
+    {
+        DirectoryInfo directory = project.Directory ?? throw new ArgumentException("Project's path does not appear to have a parent.", nameof(project));
+
+        ProjectCollection projectCollection = new(); // Create a new collection for each project to ensure environment variables aren't shared between tests
+
+        return ProjectCreator
+            .Create(path: project.FullName, sdk: ProjectCreatorConstants.SdkCsprojDefaultSdk, projectCollection: projectCollection)
+            .Import(Path.Combine(ThisAssemblyDirectory, "Sdk.props"))
+            .CustomAction(configureProject)
+            .Import(Path.Combine(ThisAssemblyDirectory, "Sdk.targets"));
+    }
+}
\ No newline at end of file
diff --git a/tests/DotNet.ReproducibleBuilds.Isolated.Tests/TargetFrameworkRootPathTests.cs b/tests/DotNet.ReproducibleBuilds.Isolated.Tests/TargetFrameworkRootPathTests.cs
new file mode 100644
index 0000000..dff6994
--- /dev/null
+++ b/tests/DotNet.ReproducibleBuilds.Isolated.Tests/TargetFrameworkRootPathTests.cs
@@ -0,0 +1,34 @@
+using DotNet.ReproducibleBuilds.Tests.Shared;
+
+using FluentAssertions;
+using Microsoft.Build.Utilities.ProjectCreation;
+
+namespace DotNet.ReproducibleBuilds.Isolated.Tests;
+
+public class TargetFrameworkRootPathTests : TestBase
+{
+    [Theory]
+    [InlineData(false)]
+    [InlineData(true)]
+    public void WarningCanBeSuppressed(bool suppress)
+    {
+        ProjectCreator.Templates
+            .ReproducibleBuildsIsolatedProject(GetRandomFile(".csproj"), configureProject: project =>
+            {
+                project.Property("TargetFramework", "net472");
+
+                if (suppress)
+                {
+                    project.Property("NoWarn", "RPB0002");
+                }
+            })
+            // Run the target directly and _not_ as part of Build because we want to test the warning path and not allow the SDK's
+            // automatic references to run.
+            .TryBuild(restore: false, target: "CheckTargetFrameworkRootPath", out bool result, out BuildOutput output);
+
+        int expected = suppress ? 0 : 1;
+
+        result.Should().BeTrue();
+        output.Warnings.Should().HaveCount(expected);
+    }
+}