No nuget access fix tests

eng/common/post-build/nuget-verification.ps1

@@ -30,7 +30,7 @@
 [CmdletBinding(PositionalBinding = $false)]
 param(
    [string]$NuGetExePath,
-   [string]$PackageSource = "https://api.nuget.org/v3/index.json",
+   [string]$PackageSource = "https://pkgs.dev.azure.com/dnceng/public/_packaging/dotnet-public/nuget/v3/index.json",
    [string]$DownloadPath,
    [Parameter(ValueFromRemainingArguments = $true)]
    [string[]]$args

test/Microsoft.TestPlatform.TestUtilities/IntegrationTestBase.cs

@@ -59,8 +59,11 @@ public IntegrationTestBase()
     {
         _testEnvironment = new IntegrationTestEnvironment();
         BuildConfiguration = IntegrationTestEnvironment.BuildConfiguration;
+
+        TempDirectory.NuGetConfigPath = Path.Combine(IntegrationTestEnvironment.RepoRootDirectory, "NuGet.config");
         TempDirectory = new TempDirectory();
 
+
         var drive = new DriveInfo(Directory.GetDirectoryRoot(TempDirectory.Path));
         Console.WriteLine($"Available space for TEMP: {drive.Name} {drive.AvailableFreeSpace / (1024 * 1024)} MB");
 

test/Microsoft.TestPlatform.TestUtilities/TempDirectory.cs

@@ -4,6 +4,7 @@
 using System;
 using System.Collections.Generic;
 using System.IO;
+using System.Runtime.CompilerServices;
 
 using IO = System.IO;
 
@@ -23,6 +24,8 @@ public TempDirectory()
 
     public string Path { get; }
 
+    public static string? NuGetConfigPath { get; set; }
+
     public void Dispose()
     {
         Dispose(true);
@@ -91,12 +94,25 @@ public string CopyFile(string filePath)
     /// <returns>
     /// Path of the created directory.
     /// </returns>
+    [MethodImpl(MethodImplOptions.Synchronized)]
     internal static string CreateUniqueDirectory()
     {
         var temp = GetTempPath();
         var directoryPath = IO.Path.Combine(temp, "vstest", RandomId.Next());
         Directory.CreateDirectory(directoryPath);
 
+        if (NuGetConfigPath == null)
+        {
+            throw new InvalidOperationException("NuGetConfigPath on TempDirectory class must be set.");
+        }
+
+        var tempNugetConfigPath = IO.Path.Combine(directoryPath, IO.Path.GetFileName(NuGetConfigPath));
+
+        if (!File.Exists(tempNugetConfigPath))
+        {
+            File.Copy(NuGetConfigPath, tempNugetConfigPath);
+        }
+
         return directoryPath;
     }