From 31c14f2ad3714c262108acf6613ab023bc971012 Mon Sep 17 00:00:00 2001
From: ayousuf23 <72010390+ayousuf23@users.noreply.github.com>
Date: Mon, 21 Feb 2022 13:02:30 -0500
Subject: [PATCH] Updated background invocation `&` operator to use
 `-WorkingDirectory` when starting a new job (#16180)

---
 .../engine/runtime/Operations/MiscOps.cs      | 31 ++++++++++++-------
 .../Microsoft.PowerShell.Core/Job.Tests.ps1   | 12 ++++++-
 2 files changed, 30 insertions(+), 13 deletions(-)

diff --git a/src/System.Management.Automation/engine/runtime/Operations/MiscOps.cs b/src/System.Management.Automation/engine/runtime/Operations/MiscOps.cs
index 62468dcfc3fe..72a676dad1cc 100644
--- a/src/System.Management.Automation/engine/runtime/Operations/MiscOps.cs
+++ b/src/System.Management.Automation/engine/runtime/Operations/MiscOps.cs
@@ -531,12 +531,8 @@ private static string GetParameterText(string parameterName)
                 var pipelineOffset = pipelineAst.Extent.StartOffset;
                 var variables = pipelineAst.FindAll(static x => x is VariableExpressionAst, true);
 
-                // Used to make sure that the job runs in the current directory
-                const string cmdPrefix = @"Microsoft.PowerShell.Management\Set-Location -LiteralPath $using:pwd ; ";
-
-                // Minimize allocations by initializing the stringbuilder to the size of the source string + prefix + space for ${using:} * 2
-                System.Text.StringBuilder updatedScriptblock = new System.Text.StringBuilder(cmdPrefix.Length + scriptblockBodyString.Length + 18);
-                updatedScriptblock.Append(cmdPrefix);
+                // Minimize allocations by initializing the stringbuilder to the size of the source string + space for ${using:} * 2
+                System.Text.StringBuilder updatedScriptblock = new System.Text.StringBuilder(scriptblockBodyString.Length + 18);
                 int position = 0;
 
                 // Prefix variables in the scriptblock with $using:
@@ -568,14 +564,25 @@ private static string GetParameterText(string parameterName)
                 var sb = ScriptBlock.Create(updatedScriptblock.ToString());
                 var commandInfo = new CmdletInfo("Start-Job", typeof(StartJobCommand));
                 commandProcessor = context.CommandDiscovery.LookupCommandProcessor(commandInfo, CommandOrigin.Internal, false, context.EngineSessionState);
-                var parameter = CommandParameterInternal.CreateParameterWithArgument(
+
+                var workingDirectoryParameter = CommandParameterInternal.CreateParameterWithArgument(
                     parameterAst: pipelineAst,
-                    "ScriptBlock",
-                    null,
+                    parameterName: "WorkingDirectory",
+                    parameterText: null,
                     argumentAst: pipelineAst,
-                    sb,
-                    false);
-                commandProcessor.AddParameter(parameter);
+                    value: context.SessionState.Path.CurrentLocation.Path,
+                    spaceAfterParameter: false);
+
+                var scriptBlockParameter = CommandParameterInternal.CreateParameterWithArgument(
+                    parameterAst: pipelineAst,
+                    parameterName: "ScriptBlock",
+                    parameterText: null,
+                    argumentAst: pipelineAst,
+                    value: sb,
+                    spaceAfterParameter: false);
+
+                commandProcessor.AddParameter(workingDirectoryParameter);
+                commandProcessor.AddParameter(scriptBlockParameter);
                 pipelineProcessor.Add(commandProcessor);
                 pipelineProcessor.LinkPipelineSuccessOutput(outputPipe ?? new Pipe(new List<object>()));
 
diff --git a/test/powershell/Modules/Microsoft.PowerShell.Core/Job.Tests.ps1 b/test/powershell/Modules/Microsoft.PowerShell.Core/Job.Tests.ps1
index 90477267b4e6..2cf4f04dde08 100644
--- a/test/powershell/Modules/Microsoft.PowerShell.Core/Job.Tests.ps1
+++ b/test/powershell/Modules/Microsoft.PowerShell.Core/Job.Tests.ps1
@@ -178,7 +178,7 @@ Describe "Debug-job test" -Tag "Feature" {
     }
 }
 
-Describe "Ampersand background test" -Tag "CI","Slow" {
+Describe "Ampersand background test" -Tag "CI", "Slow" {
     Context "Simple background job" {
         AfterEach {
             Get-Job | Remove-Job -Force
@@ -218,6 +218,16 @@ Describe "Ampersand background test" -Tag "CI","Slow" {
             $j = Get-Location | ForEach-Object -MemberName Path &
             Receive-Job -Wait $j | Should -Be ($PWD.Path)
         }
+        It "Make sure Set-Location is not used in the job's script block to set the working directory" {
+            $j = (Get-Variable -Value ExecutionContext).SessionState.PSVariable.Get("MyInvocation").Value.MyCommand.ScriptBlock & 
+            (Receive-Job -Wait $j).ToString() | Should -BeExactly "(Get-Variable -Value ExecutionContext).SessionState.PSVariable.Get(`"MyInvocation`").Value.MyCommand.ScriptBlock"
+        }
+        It "Test that changing working directory also changes background job's working directory" {
+            Set-Location ..
+            $WorkingDirectory = (Get-Location).ToString()
+            $BackgroundJob = (Get-Location &) 
+            (Receive-Job -Wait $BackgroundJob).ToString() | Should -BeExactly $WorkingDirectory
+        }
         It "Test that output redirection is done in the background job" {
             $j = Write-Output hello > $TESTDRIVE/hello.txt &
             Receive-Job -Wait $j | Should -BeNullOrEmpty