Add a generic file watcher function in HelpersCommon.psm1 (#4775)

Add a generic file watcher function in HelpersCommon.psm1 and update some tests to use the `Wait-FileToBePresent`.

test/powershell/Language/Scripting/NativeExecution/NativeCommandProcessor.Tests.ps1

@@ -196,19 +196,13 @@ Categories=Application;
         elseif ($IsLinux) {
             # Validate on Linux by reassociating default app for text file
             & $TestFile
-            $startTime = Get-Date
             # It may take time for handler to start
-            while (((Get-Date) - $startTime).TotalSeconds -lt 10 -and (-not (Test-Path "$HOME/nativeCommandProcessor.Success"))) {
-                Start-Sleep -Milliseconds 100
-            }
+            Wait-FileToBePresent -File "$HOME/nativeCommandProcessor.Success" -TimeoutInSeconds 10 -IntervalInMilliseconds 100
             Get-Content $HOME/nativeCommandProcessor.Success | Should Be $TestFile
         }
         else {
             & $TestFile
-            $startTime = Get-Date
-            while (((Get-Date) - $startTime).TotalSeconds -lt 10 -and (!(Test-Path $TestDrive\foo.txt))) {
-                Start-Sleep -Milliseconds 100
-            }
+            Wait-FileToBePresent -File $TestDrive\foo.txt -TimeoutInSeconds 10 -IntervalInMilliseconds 100
             "$TestDrive\foo.txt" | Should Exist
             Get-Content $TestDrive\foo.txt | Should BeExactly $TestFile
         }

test/powershell/Modules/Microsoft.PowerShell.Management/FileSystem.Tests.ps1

@@ -233,12 +233,7 @@ Describe "Basic FileSystem Provider Tests" -Tags "CI" {
             "Test timeout waiting for $cmdLine" | Set-Content -Path $errFile
 
             runas.exe /trustlevel:0x20000 "$powershell -nop -c try { $cmdline -ErrorAction Stop } catch { `$_.FullyQualifiedErrorId | Out-File $errFile }; New-Item -Type File -Path $doneFile"
-
-            $startTime = Get-Date
-            while (((Get-Date) - $startTime).TotalSeconds -lt 15 -and -not (Test-Path $doneFile))
-            {
-                Start-Sleep -Milliseconds 100
-            }
+            Wait-FileToBePresent -File $doneFile -TimeoutInSeconds 15 -IntervalInMilliseconds 100
 
             $err = Get-Content $errFile
             $err | Should Be $expectedError

test/powershell/Modules/Microsoft.PowerShell.Management/Start-Process.Tests.ps1

@@ -133,11 +133,9 @@ Describe "Start-Process tests requiring admin" -Tags "Feature","RequireAdminOnWi
         $fooFile = Join-Path $TestDrive "FooTest.foo"
         New-Item $fooFile -ItemType File -Force
         Start-Process $fooFile
-        $startTime = Get-Date
-        while (((Get-Date) - $startTime).TotalSeconds -lt 10 -and (!(Test-Path $testdrive\foo.txt)))
-        {
-            Start-Sleep -Milliseconds 100
-        }
+
+        Wait-FileToBePresent -File "$testdrive\foo.txt" -TimeoutInSeconds 10 -IntervalInMilliseconds 100
+
         "$testdrive\foo.txt" | Should Exist
         Get-Content $testdrive\foo.txt | Should BeExactly $fooFile
     }

test/powershell/Modules/Microsoft.PowerShell.Utility/Invoke-Item.Tests.ps1

@@ -125,12 +125,8 @@ Categories=Application;
 
                 $before = $windows.Count
                 Invoke-Item -Path $PSHOME
-                $startTime = Get-Date
                 # may take time for explorer to open window
-                while (((Get-Date) - $startTime).TotalSeconds -lt 10 -and ($windows.Count -eq $before))
-                {
-                    Start-Sleep -Milliseconds 100
-                }
+                Wait-UntilTrue -sb { $windows.Count -gt $before } -TimeoutInMilliseconds (10*1000) -IntervalInMilliseconds 100 > $null
                 $after = $windows.Count
 
                 $before + 1 | Should Be $after
@@ -143,12 +139,8 @@ Categories=Application;
             {
                 # validate on Unix by reassociating default app for directories
                 Invoke-Item -Path $PSHOME
-                $startTime = Get-Date
                 # may take time for handler to start
-                while (((Get-Date) - $startTime).TotalSeconds -lt 10 -and (-not (Test-Path "$HOME/InvokeItemTest.Success")))
-                {
-                    Start-Sleep -Milliseconds 100
-                }
+                Wait-FileToBePresent -File "$HOME/InvokeItemTest.Success" -TimeoutInSeconds 10 -IntervalInMilliseconds 100
                 Get-Content $HOME/InvokeItemTest.Success | Should Be $PSHOME
             }
             else

test/powershell/Modules/Microsoft.WSMan.Management/CredSSP.Tests.ps1

@@ -100,11 +100,7 @@ Describe "CredSSP cmdlet tests" -Tags 'Feature','RequireAdminOnWindows' {
         param ($cmdline, $cmd)
 
         runas.exe /trustlevel:0x20000 "$powershell -nop -c try { $cmdline } catch { `$_.FullyQualifiedErrorId | Out-File $errtxt }; New-Item -Type File -Path $donefile"
-        $startTime = Get-Date
-        while (((Get-Date) - $startTime).TotalSeconds -lt 5 -and -not (Test-Path "$donefile"))
-        {
-            Start-Sleep -Milliseconds 100
-        }
+        Wait-FileToBePresent -File $donefile -TimeoutInSeconds 5 -IntervalInMilliseconds 100
         $errtxt | Should Exist
         $err = Get-Content $errtxt
         $err | Should Be "System.InvalidOperationException,Microsoft.WSMan.Management.$cmd"

test/tools/Modules/HelpersCommon/HelpersCommon.psd1

@@ -16,6 +16,6 @@ Copyright = 'Copyright (C) Microsoft Corporation, All rights reserved.'
 
 Description = 'Temporary module contains functions for using in tests'
 
-FunctionsToExport = 'Wait-UntilTrue', 'Test-IsElevated', 'ShouldBeErrorId'
+FunctionsToExport = 'Wait-UntilTrue', 'Test-IsElevated', 'ShouldBeErrorId', 'Wait-FileToBePresent'
 
 }

test/tools/Modules/HelpersCommon/HelpersCommon.psm1

@@ -11,18 +11,28 @@ function Wait-UntilTrue
 
     # Loop until the script block evaluates to true
     while (-not ($sb.Invoke())) {
-        # Sleep for the specified interval
-        start-sleep -mil $intervalInMilliseconds
-
-        # If the timeout period has passed, throw an exception
-        if (([DateTime]::Now - $startTime).TotalMilliseconds -gt $timeoutInMilliseconds)
-        {
+        # If the timeout period has passed, return false
+        if (([DateTime]::Now - $startTime).TotalMilliseconds -gt $timeoutInMilliseconds) {
             return $false
         }
+        # Sleep for the specified interval
+        Start-Sleep -Milliseconds $intervalInMilliseconds
     }
     return $true
 }
 
+function Wait-FileToBePresent
+{
+    [CmdletBinding()]
+    param (
+        [string]$File,
+        [int]$TimeoutInSeconds = 10,
+        [int]$IntervalInMilliseconds = 100
+    )
+
+    Wait-UntilTrue -sb { Test-Path $File } -TimeoutInMilliseconds ($TimeoutInSeconds*1000) -IntervalInMilliseconds $IntervalInMilliseconds > $null
+}
+
 function Test-IsElevated
 {
     $IsElevated = $False