tighten up Invoke-SharedPesterTest.ps1

Author: bcullman

tools/Invoke-SharedPesterTests.ps1

@@ -15,6 +15,15 @@ $repoRoot = [System.IO.Path]::GetFullPath((Join-Path $PSScriptRoot ".."))
 $originalSystemRoot = $env:SystemRoot
 $originalTemp = $env:TEMP
 
+function Assert-PesterEnvironment {
+    if ($PSVersionTable.PSEdition -eq "Core" -and -not $IsWindows) {
+        $referenceAssembliesPath = Join-Path $PSHOME "ref"
+        if (-not (Test-Path -Path $referenceAssembliesPath)) {
+            throw "Pester 3.4.3 on macOS requires a compatible pwsh installation with reference assemblies under '$referenceAssembliesPath'. This runner is intentionally lean and does not patch Pester at runtime."
+        }
+    }
+}
+
 function Get-PesterModulePath {
     $packagesFolder = Join-Path $repoRoot "packages"
     $localPesterPaths = @(
@@ -24,80 +33,26 @@ function Get-PesterModulePath {
 
     foreach ($localPesterPath in $localPesterPaths) {
         if (Test-Path -Path $localPesterPath) {
+            $localManifestPath = Join-Path $localPesterPath "Pester.psd1"
+            if (Test-Path -Path $localManifestPath) {
+                return $localManifestPath
+            }
+
             return $localPesterPath
         }
     }
 
     $globalPester = Get-Module -ListAvailable Pester | Where-Object { $_.Version -eq [version]"3.4.3" } | Select-Object -First 1
     if ($globalPester) {
-        return $globalPester.ModuleBase
+        return $globalPester.Path
     }
 
     throw "Pester 3.4.3 was not found in the repository packages folder or installed modules."
 }
 
-function Import-PatchedPester {
-    param(
-        [Parameter(Mandatory = $true)]
-        [string] $PesterModulePath
-    )
-
-    $patchedPesterPath = Join-Path ([System.IO.Path]::GetTempPath()) ("Pester.3.4.3-pwsh-compatible-{0}" -f ([guid]::NewGuid().ToString("N")))
-
-    Copy-Item -Path $PesterModulePath -Destination $patchedPesterPath -Recurse -Force
-
-    $setupTeardownPath = Join-Path $patchedPesterPath "Functions" "SetupTeardown.ps1"
-    $setupTeardown = [System.IO.File]::ReadAllText($setupTeardownPath)
-
-    $addTypePattern = '& \$SafeCommands\[''Add-Type''\] -TypeDefinition @''[\s\S]*?''@\r?\n\r?\n'
-    $setupTeardown = [System.Text.RegularExpressions.Regex]::Replace($setupTeardown, $addTypePattern, "", 1)
-
-    $setupTeardown = $setupTeardown.Replace(
-        '$closeIndex = [Pester.ClosingBraceFinder]::GetClosingBraceIndex($Tokens, $GroupStartTokenIndex)',
-@'
-    $groupLevel = 1
-    $closeIndex = -1
-
-    for ($i = $GroupStartTokenIndex + 1; $i -lt $Tokens.Length; $i++)
-    {
-        $type = $Tokens[$i].Type
-
-        if ($type -eq [System.Management.Automation.PSTokenType]::GroupStart)
-        {
-            $groupLevel++
-        }
-        elseif ($type -eq [System.Management.Automation.PSTokenType]::GroupEnd)
-        {
-            $groupLevel--
-
-            if ($groupLevel -le 0)
-            {
-                $closeIndex = $i
-                break
-            }
-        }
-    }
-'@)
-
-    [System.IO.File]::WriteAllText($setupTeardownPath, $setupTeardown)
-
-    Remove-Module Pester -ErrorAction SilentlyContinue
-    Import-Module -Name (Join-Path $patchedPesterPath "Pester.psd1") -Force -ErrorAction Stop
-}
-
 function Import-Pester {
     $pesterModulePath = Get-PesterModulePath
-
-    try {
-        Import-Module -Name $pesterModulePath -RequiredVersion 3.4.3 -ErrorAction Stop
-    } catch {
-        if ($PSVersionTable.PSEdition -eq "Core" -and -not $IsWindows) {
-            Write-Host "Importing a patched temporary copy of Pester 3.4.3 for pwsh compatibility."
-            Import-PatchedPester -PesterModulePath $pesterModulePath
-        } else {
-            throw
-        }
-    }
+    Import-Module -Name $pesterModulePath -RequiredVersion 3.4.3 -ErrorAction Stop
 }
 
 function Get-TestFiles {
@@ -144,8 +99,6 @@ try {
         Import-Module -Name $modulePath -ErrorAction Stop
     }
 
-    Import-Pester
-
     if ($BeforeRun) {
         & $BeforeRun
     }
@@ -156,6 +109,8 @@ try {
         return
     }
 
+    Assert-PesterEnvironment
+    Import-Pester
     Invoke-SelectedTests -TestFiles $testFiles
 } finally {
     $env:SystemRoot = $originalSystemRoot