Revert dropping support of Powershell 3 and friends (#2435)

* Revert dropping support of powershell 3 etc.

* Update lock and fix reverted change

CONTRIBUTING.md

@@ -94,7 +94,7 @@ Get-Help ./test.ps1 -Detailed
 
 The Azure Devops Pipeline azure-pipelines.yml file contains the code definition used for builds, unit and integration tests in the CI pipeline.
 
-Within the pipeline, tests are executed against PS7 and PS5.1, on Windows, Linux (Ubuntu) and MacOS.
+Within the pipeline, tests are executed against PS7 Core on a strategy matrix of machines, including Ubuntu 16.04, 18.04, macOS Mojave 10.14, Catalina 10.15, Windows Server 2016, 2019. Tests are also executed against PS6.2, PS4, PS3.
 
 ## Documentation
 

README.md

@@ -67,7 +67,7 @@ The example above also has an [annotated and production ready version here](docs
 
 ## Installation
 
-Pester runs on Windows, Linux, MacOS and anywhere else thanks to PowerShell. It is compatible with Windows PowerShell 5.1 and PowerShell 7.2 and newer.
+Pester runs on Windows, Linux, MacOS and anywhere else thanks to PowerShell. It is compatible with Windows PowerShell 3, 4, 5, 6 and 7.
 
 Pester 3 comes pre-installed with Windows 10, but we recommend updating, by running this PowerShell command _as administrator_:
 

azure-pipelines.yml

@@ -126,3 +126,50 @@ stages:
               failTaskOnFailedTests: true
             condition: succeededOrFailed()
         timeoutInMinutes: 20
+      - job:
+        workspace:
+          clean: all
+        strategy:
+          matrix:
+            PS3:
+              agent: 'ps3'
+              pwsh: false
+            PS4:
+              agent: 'ps4'
+              pwsh: false
+            PS6_2:
+              agent: 'ps6'
+              pwsh: true
+        pool:
+          name: Default
+          demands:
+            - agent.name -equals $(agent)
+        steps:
+          - checkout: none
+          - task: DownloadPipelineArtifact@2
+            inputs:
+              buildType: 'current'
+              artifactName: 'all'
+              targetPath: '$(Build.SourcesDirectory)'
+          - task: PowerShell@2
+            displayName: 'Test Pester'
+            inputs:
+              targetType: 'inline'
+              pwsh: $(pwsh)
+              script: |
+                & ./test.ps1 -CI -PassThru -NoBuild
+              workingDirectory: '$(Build.SourcesDirectory)'
+          - task: PublishCodeCoverageResults@1
+            inputs:
+              codeCoverageTool: 'JaCoCo'
+              summaryFileLocation: 'coverage.xml'
+              pathToSources: 'src/'
+              failIfCoverageEmpty: false
+            condition: succeededOrFailed()
+          - task: PublishTestResults@2
+            inputs:
+              testResultsFormat: 'NUnit'
+              testResultsFiles: 'testResults.xml'
+              failTaskOnFailedTests: true
+            condition: succeededOrFailed()
+        timeoutInMinutes: 20

build.ps1

@@ -115,8 +115,10 @@ if ($Clean) {
         , ("$PSScriptRoot/src/schemas/NUnit25/*.xsd", "$PSScriptRoot/bin/schemas/NUnit25/")
         , ("$PSScriptRoot/src/schemas/NUnit3/*.xsd", "$PSScriptRoot/bin/schemas/NUnit3/")
         , ("$PSScriptRoot/src/schemas/JaCoCo/*.dtd", "$PSScriptRoot/bin/schemas/JaCoCo/")
-        , ("$PSScriptRoot/src/csharp/Pester/bin/$Configuration/net462/Pester.dll", "$PSScriptRoot/bin/bin/net462/")
-        , ("$PSScriptRoot/src/csharp/Pester/bin/$Configuration/net6.0/Pester.dll", "$PSScriptRoot/bin/bin/net6.0/")
+        , ("$PSScriptRoot/src/csharp/Pester/bin/$Configuration/net452/Pester.dll", "$PSScriptRoot/bin/bin/net452/")
+        , ("$PSScriptRoot/src/csharp/Pester/bin/$Configuration/net452/Pester.pdb", "$PSScriptRoot/bin/bin/net452/")
+        , ("$PSScriptRoot/src/csharp/Pester/bin/$Configuration/netstandard2.0/Pester.dll", "$PSScriptRoot/bin/bin/netstandard2.0/")
+        , ("$PSScriptRoot/src/csharp/Pester/bin/$Configuration/netstandard2.0/Pester.pdb", "$PSScriptRoot/bin/bin/netstandard2.0/")
     )
 }
 
@@ -125,10 +127,10 @@ Copy-Content -Content $content
 if ($Clean) {
     # update help for New-PesterConfiguration
     if ($PSVersionTable.PSVersion.Major -gt 5) {
-        $null = [Reflection.Assembly]::LoadFrom("$PSScriptRoot/bin/bin/net6.0/Pester.dll")
+        $null = [Reflection.Assembly]::LoadFrom("$PSScriptRoot/bin/bin/netstandard2.0/Pester.dll")
     }
     else {
-        $null = [Reflection.Assembly]::LoadFrom("$PSScriptRoot/bin/bin/net462/Pester.dll")
+        $null = [Reflection.Assembly]::LoadFrom("$PSScriptRoot/bin/bin/net452/Pester.dll")
     }
 
     function Format-NicelyMini ($value) {

publish/release.ps1

@@ -60,8 +60,10 @@ $files = @(
     'Pester.psm1'
     'Pester.Format.ps1xml'
     'PesterConfiguration.Format.ps1xml'
-    'bin/net462/Pester.dll'
-    'bin/net6.0/Pester.dll'
+    'bin/net452/Pester.dll'
+    'bin/net452/Pester.pdb'
+    'bin/netstandard2.0/Pester.dll'
+    'bin/netstandard2.0/Pester.pdb'
     'en-US/about_BeforeEach_AfterEach.help.txt'
     'en-US/about_Mocking.help.txt'
     'en-US/about_Pester.help.txt'

src/Pester.Types.ps1

@@ -13,25 +13,25 @@ if ($null -ne $configurationType) {
 }
 
 if ($PSVersionTable.PSVersion.Major -ge 6) {
-    $path = "$PSScriptRoot/bin/net6.0/Pester.dll"
+    $path = "$PSScriptRoot/bin/netstandard2.0/Pester.dll"
     # PESTER_BUILD
     if ((Get-Variable -Name "PESTER_BUILD" -ValueOnly -ErrorAction Ignore)) {
-        $path = "$PSScriptRoot/../bin/bin/net6.0/Pester.dll"
+        $path = "$PSScriptRoot/../bin/bin/netstandard2.0/Pester.dll"
     }
     else {
-        $path = "$PSScriptRoot/../bin/bin/net6.0/Pester.dll"
+        $path = "$PSScriptRoot/../bin/bin/netstandard2.0/Pester.dll"
     }
     # end PESTER_BUILD
     & $SafeCommands['Add-Type'] -Path $path
 }
 else {
-    $path = "$PSScriptRoot/bin/net462/Pester.dll"
+    $path = "$PSScriptRoot/bin/net452/Pester.dll"
     # PESTER_BUILD
     if ((Get-Variable -Name "PESTER_BUILD" -ValueOnly -ErrorAction Ignore)) {
-        $path = "$PSScriptRoot/../bin/bin/net462/Pester.dll"
+        $path = "$PSScriptRoot/../bin/bin/net452/Pester.dll"
     }
     else {
-        $path = "$PSScriptRoot/../bin/bin/net462/Pester.dll"
+        $path = "$PSScriptRoot/../bin/bin/net452/Pester.dll"
     }
     # end PESTER_BUILD
     & $SafeCommands['Add-Type'] -Path $path

src/Pester.psd1

@@ -1,4 +1,4 @@
-@{
+@{
 
     # Script module or binary module file associated with this manifest.
     RootModule        = 'Pester.psm1'
@@ -22,7 +22,7 @@
     Description       = 'Pester provides a framework for running BDD style Tests to execute and validate PowerShell commands inside of PowerShell and offers a powerful set of Mocking Functions that allow tests to mimic and mock the functionality of any command inside of a piece of PowerShell code being tested. Pester tests can execute any command or script that is accessible to a pester test file. This can include functions, Cmdlets, Modules and scripts. Pester can be run in ad hoc style in a console or it can be integrated into the Build scripts of a Continuous Integration system.'
 
     # Minimum version of the Windows PowerShell engine required by this module
-    PowerShellVersion = '5.1'
+    PowerShellVersion = '3.0'
 
     # Type files (.ps1xml) to be loaded when importing this module
     TypesToProcess    = @()

src/csharp/Pester/Pester.csproj

@@ -1,31 +1,21 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFrameworks>net6.0;net462</TargetFrameworks>
+    <TargetFrameworks>netstandard2.0;net452</TargetFrameworks>
     <LangVersion>latest</LangVersion>
     <RestorePackagesWithLockFile>true</RestorePackagesWithLockFile>
-    <DebugType>embedded</DebugType>
   </PropertyGroup>
 
-  <!-- PowerShell 7.2.x is the oldest supported PowerShell version. That version is built using net6.0.
-  But there is a bug in 7.2.0 reference assemblies, up to 7.2.10, where the IExtens.File is missing from the reference assembly:
-  https://github.com/PowerShell/PowerShell/issues/16408
-
-  So we use the version released before 7.2.0 which was 7.1.7. We could probably use 7.2.10 safely as well,
-  -->
-  <ItemGroup Condition="'$(TargetFramework)' == 'net6.0'">
-    <PackageReference Include="System.Management.Automation" Version="7.1.7" />
+  <ItemGroup Condition="'$(TargetFramework)' == 'netstandard2.0'">
+    <!-- this version is used specifically to support as old version of PS6 as we can.
+    issue: https://github.com/pester/Pester/issues/2207 -->
+    <PackageReference Include="System.Management.Automation" Version="6.0.4" NoWarn="NU1903" />
   </ItemGroup>
 
-  <!-- Windows PowerShell 5.1 is the only Windows PowerShell that is still in support, and it is built using .NET Framework 4.5.2.
-  But the oldest still supported OS on which WMF5.1 can be installed, is Windows 10 1607, which comes with .NET Framework 4.6.2. https://learn.microsoft.com/en-us/powershell/scripting/windows-powershell/wmf-overview?view=powershell-7.4#wmf-availability-across-windows-operating-systems
-  https://learn.microsoft.com/en-us/dotnet/framework/migration-guide/versions-and-dependencies#net-framework-462
-  .NET 4.6.2 is also the oldest supported version of .NET Framework (https://learn.microsoft.com/en-us/lifecycle/products/microsoft-net-framework)
-  -->
-  <ItemGroup Condition="'$(TargetFramework)' == 'net462'">
-    <PackageReference Include="Microsoft.PowerShell.5.1.ReferenceAssemblies" Version="1.0.0" />
+  <ItemGroup Condition="'$(TargetFramework)' == 'net452'">
+    <PackageReference Include="Microsoft.PowerShell.3.ReferenceAssemblies" Version="1.0.0" />
 
-    <!-- To enable build support on unix. -->
+    <!-- To enable build support on unix-->
     <PackageReference Include="Microsoft.NETFramework.ReferenceAssemblies" Version="1.0.0">
       <PrivateAssets>all</PrivateAssets>
       <IncludeAssets>runtime; build; native; contentfiles; analyzers</IncludeAssets>