feat(ci): add a Windows PowerShell 5.1 Pester leg

.github/workflows/test.yml

@@ -110,6 +110,40 @@ jobs:
         shell: pwsh
         run: Invoke-Pester tests/powershell/ -Output Detailed
 
+  powershell51-tests:
+    name: PowerShell 5.1 tests (Pester)
+    needs: detect-changes
+    # Advisory only: not registered in the ruleset's required-check set
+    # yet, so a failure here does not block merges (#166). Promotion to
+    # required is a later decision once this leg proves stable.
+    # always() overrides the default "skip if a need failed" behavior
+    # so a failed/cancelled detect-changes fails open to running the
+    # real job, rather than silently skipping it (which would satisfy
+    # the required-status-check gate without ever having run).
+    if: |
+      always() &&
+      (needs.detect-changes.result != 'success' || needs.detect-changes.outputs.requires_full_ci == 'true')
+    runs-on: windows-latest
+    steps:
+      - uses: actions/checkout@v7
+      - name: Confirm Windows PowerShell 5.1
+        shell: powershell
+        run: |
+          $PSVersionTable.PSVersion
+          if ($PSVersionTable.PSVersion.Major -ne 5) {
+            throw "Expected Windows PowerShell 5.1 (major version 5), got $($PSVersionTable.PSVersion)"
+          }
+      - name: Install Pester if needed
+        shell: powershell
+        run: |
+          if (-not (Get-Module -ListAvailable Pester |
+              Where-Object { $_.Version -ge [version]'5.0' })) {
+            Install-Module Pester -MinimumVersion 5.0 -Force -SkipPublisherCheck -Scope CurrentUser
+          }
+      - name: Run Pester tests
+        shell: powershell
+        run: Invoke-Pester tests/powershell/ -Output Detailed
+
   lua-syntax:
     name: Lua syntax check
     needs: detect-changes

tests/powershell/02-cargo.Tests.ps1

@@ -9,7 +9,7 @@ BeforeAll {
   ) '02-cargo.ps1'
 }
 
-Describe '02-cargo (Unix pwsh)' -Skip:($IsWindows -eq $true) {
+Describe '02-cargo (Unix pwsh)' -Skip:($IsWindows -ne $false) {
 
   BeforeEach {
     $script:OriginalHome = $HOME

tests/powershell/secret-status.Tests.ps1

@@ -92,7 +92,7 @@ Describe 'secret-status.ps1' {
     @($obj.rows | Where-Object status -eq 'MISSING').Count | Should -BeGreaterThan 0
   }
 
-  It 'secret file present with correct mode is OK' -Skip:($IsWindows -eq $true) {
+  It 'secret file present with correct mode is OK' -Skip:($IsWindows -ne $false) {
     $f = Join-Path $HomeDir 'secret.txt'
     Set-Content -LiteralPath $f -Value 'secret'
     & chmod 600 $f
@@ -107,7 +107,7 @@ Describe 'secret-status.ps1' {
     $r.Output | Should -Match 'OK'
   }
 
-  It 'secret file with wrong mode is WARN' -Skip:($IsWindows -eq $true) {
+  It 'secret file with wrong mode is WARN' -Skip:($IsWindows -ne $false) {
     $f = Join-Path $HomeDir 'secret-bad.txt'
     Set-Content -LiteralPath $f -Value 'secret'
     & chmod 644 $f
@@ -156,7 +156,7 @@ Describe 'secret-status.ps1' {
     $r.Output | Should -Match 'ghq root unresolved'
   }
 
-  It 'env file warns when filename not in .gitignore' -Skip:($IsWindows -eq $true) {
+  It 'env file warns when filename not in .gitignore' -Skip:($IsWindows -ne $false) {
     $repo = Join-Path $HomeDir 'repo-warn'
     New-Item -ItemType Directory -Force -Path (Join-Path $repo '.git') | Out-Null
     $envPath = Join-Path $repo '.env'
@@ -175,7 +175,7 @@ Describe 'secret-status.ps1' {
     $r.Output | Should -Match 'not in .gitignore'
   }
 
-  It 'env file OK when gitignore lists filename' -Skip:($IsWindows -eq $true) {
+  It 'env file OK when gitignore lists filename' -Skip:($IsWindows -ne $false) {
     $repo = Join-Path $HomeDir 'repo-ok'
     New-Item -ItemType Directory -Force -Path (Join-Path $repo '.git') | Out-Null
     $envPath = Join-Path $repo '.env'
@@ -210,7 +210,7 @@ Describe 'secret-status.ps1' {
   }
 }
 
-Describe 'secret-status.ps1 DRIFT detection' -Skip:($IsWindows -eq $true) {
+Describe 'secret-status.ps1 DRIFT detection' -Skip:($IsWindows -ne $false) {
   BeforeAll {
     $script:StatePath = Join-Path $HomeDir '.config/chezmoi/secret-deploy-state.json'
     $script:OrigHome = $env:HOME