Cleanup script to be run before CI workflow (#317)

* Cleanup script to be run before CI workflow

tools/ci_ensure_cleanup.ps1

@@ -0,0 +1,34 @@
+#
+# Copyright (c) .NET Foundation and contributors. All rights reserved.
+# Licensed under the MIT license. See LICENSE file in the project root for full license information.
+#
+
+<#
+.SYNOPSIS
+    This script is run before each CI run to ensure things are properly cleaned up
+.DESCRIPTION
+    This script is run before each CI run to ensure things are properly cleaned up
+.PARAMETER dropLocation
+
+#>
+$ErrorActionPreference = 'Stop'
+
+# If two tests are run too closely, VBCSCompiler process might still be alive for previous test preventing dotnet and packages to be cleand up
+function KillVBCSCompilers() {
+    $procs = Get-WmiObject Win32_Process | Where-Object { $_.Name.ToLower().StartsWith("dotnet") -and $_.CommandLine.ToLower().Contains("vbcscompiler") }
+    foreach ($proc in $procs) {
+        Stop-Process -Id $proc.ProcessId -Force
+    }
+}
+
+# Some failed test would actually cause appHost config file to become corrupted and w3svc would not be able to start
+function EnsureAppHostConfig() {
+    $appConfigLocation = [System.IO.Path]::Combine($env:WinDir, "System32", "inetsrv", "config", "applicationHost.config")
+    if (!(Test-Path $appConfigLocation) -or ((Get-Item $appConfigLocation).Length -eq 0)) {
+        $appConfigBackupLocation = "${appConfigLocation}.ancmtest.masterbackup"
+        Copy-Item -Path $appConfigBackupLocation -Destination $appConfigLocation -Force
+    }
+}
+
+KillVBCSCompilers
+EnsureAppHostConfig

tools/install_sharedfx.ps1

@@ -22,7 +22,7 @@ param(
     [string]
     $dotnetHome = (Join-Path $env:USERPROFILE ".dotnet")
 )
-
+$ErrorActionPreference = 'Stop'
 Import-Module -Name (Join-Path $PSScriptRoot versions.psm1) -Force
 
 function InstallDotnet([string] $arch) {