style: align test scaffolding with canonical PSMTplt

Apply the three style rules from PowerShellModuleTemplate#23 to the
Help/Meta/MetaFixers test files this repo inherited from the template:

- Named parameters on multi-arg cmdlet calls (Split-Path, Join-Path,
  Test-Path, Get-Module, Get-Content, Select-String, Get-TextFilesList,
  Test-FileUnicode)
- ValidateNotNull / ValidateNotNullOrEmpty validators on mandatory
  param entries in tests/MetaFixers.psm1
- Test-FileUnicode call inside Get-UnicodeFilesList now uses named
  -FileInfo parameter

Also restores the PR #23-era multi-paramset mandatory-skip block on
the 'Has correct [mandatory] value' It in Help.tests.ps1 (this repo
was carrying the pre-#23 version that doesn't handle parameters with
varying IsMandatory status across parameter sets), and fixes a stale
$parameterNames reference in the last Context block (should be
$commandParameterNames). Both bundled in per the cross-repo audit.

tests/Manifest.tests.ps1 is the older Module Dependency variant
(no Test-VersionConstraint helper, -Child typo on Join-Path) and is
deferred to a separate uplift PR.

Behavior is unchanged for parameters with consistent IsMandatory across
sets; previously-failing-or-flaky tests on multi-paramset parameters
will now skip with a clear reason.

Author: tablackburn

tests/Help.tests.ps1

@@ -72,7 +72,7 @@ BeforeDiscovery {
         # the values it needs (BHPSModuleManifest, BHProjectName) — when running
         # via ./build.ps1 this happens before psake; running tests in isolation
         # bypasses that, so we do it here.
-        Set-BuildEnvironment -Path (Split-Path -Parent $PSScriptRoot) -Force
+        Set-BuildEnvironment -Path (Split-Path -Path $PSScriptRoot -Parent) -Force
         $buildFilePath = Join-Path -Path $PSScriptRoot -ChildPath '..\build.psake.ps1'
         $invokePsakeParameters = @{
             TaskList  = 'Build'
@@ -82,10 +82,10 @@ BeforeDiscovery {
     }
 
     # PowerShellBuild outputs to Output/<ModuleName>/<Version>/, override BHBuildOutput
-    $projectRoot = Split-Path -Parent $PSScriptRoot
-    $sourceManifest = Join-Path $projectRoot "$Env:BHProjectName/$Env:BHProjectName.psd1"
+    $projectRoot = Split-Path -Path $PSScriptRoot -Parent
+    $sourceManifest = Join-Path -Path $projectRoot -ChildPath "$Env:BHProjectName/$Env:BHProjectName.psd1"
     $moduleVersion = (Import-PowerShellDataFile -Path $sourceManifest).ModuleVersion
-    $Env:BHBuildOutput = Join-Path $projectRoot "Output/$Env:BHProjectName/$moduleVersion"
+    $Env:BHBuildOutput = Join-Path -Path $projectRoot -ChildPath "Output/$Env:BHProjectName/$moduleVersion"
 
     # Define the path to the module manifest
     $moduleManifestFilename = $Env:BHProjectName + '.psd1'
@@ -97,18 +97,18 @@ BeforeDiscovery {
         'Classes'
     ) | ForEach-Object {
         $path = Join-Path -Path $Env:BHBuildOutput -ChildPath $_
-        if (Test-Path $path) {
+        if (Test-Path -Path $path) {
             $global:CustomTypes += (Get-ChildItem -Path $path -Recurse -ErrorAction 'SilentlyContinue').BaseName
         }
     }
 
     # Remove all versions of the module from the session. Pester can't handle multiple versions.
-    Get-Module $Env:BHProjectName | Remove-Module -Force -ErrorAction 'Ignore'
+    Get-Module -Name $Env:BHProjectName | Remove-Module -Force -ErrorAction 'Ignore'
     Import-Module -Name $moduleManifestPath -Verbose:$false -ErrorAction 'Stop'
 
     # Get module commands
     $getCommandParameters = @{
-        Module      = (Get-Module $Env:BHProjectName)
+        Module      = (Get-Module -Name $Env:BHProjectName)
         CommandType = [System.Management.Automation.CommandTypes[]]'Cmdlet, Function' # Not alias
     }
     if ($PSVersionTable.PSVersion.Major -lt 6) {
@@ -130,7 +130,7 @@ BeforeAll {
         # the values it needs (BHPSModuleManifest, BHProjectName) — when running
         # via ./build.ps1 this happens before psake; running tests in isolation
         # bypasses that, so we do it here.
-        Set-BuildEnvironment -Path (Split-Path -Parent $PSScriptRoot) -Force
+        Set-BuildEnvironment -Path (Split-Path -Path $PSScriptRoot -Parent) -Force
         $buildFilePath = Join-Path -Path $PSScriptRoot -ChildPath '..\build.psake.ps1'
         $invokePsakeParameters = @{
             TaskList  = 'Build'
@@ -212,8 +212,20 @@ Describe "Test help for <_.Name>" -ForEach $commands {
 
         # Required value in Help should match IsMandatory property of parameter
         It 'Has correct [mandatory] value' {
-            $codeMandatory = $_.IsMandatory.toString()
-            $parameterHelp.Required | Should -Be $codeMandatory
+            # Skip parameters that have different mandatory status across parameter sets
+            $parameterSetsWithParam = $command.ParameterSets | Where-Object { $_.Parameters.Name -contains $parameterName }
+            $mandatoryValues = $parameterSetsWithParam | ForEach-Object {
+                ($_.Parameters | Where-Object { $_.Name -eq $parameterName }).IsMandatory
+            } | Sort-Object -Unique
+
+            if ($mandatoryValues.Count -gt 1) {
+                Set-ItResult -Skipped -Because "Parameter '$parameterName' has varying mandatory status across parameter sets"
+                return
+            }
+
+            $codeMandatory = $_.IsMandatory.toString().ToLower()
+            $helpRequired = $parameterHelp.Required.ToLower()
+            $helpRequired | Should -Be $codeMandatory
         }
 
         # Parameter type in help should match code
@@ -233,7 +245,7 @@ Describe "Test help for <_.Name>" -ForEach $commands {
 
         # Shouldn't find extra parameters in help
         It 'finds help parameter in code: <_>' {
-            $_ -in $parameterNames | Should -Be $true
+            $_ -in $commandParameterNames | Should -Be $true
         }
     }
 }

tests/Meta.tests.ps1

@@ -9,11 +9,11 @@ BeforeAll {
         $projectRoot = $PSScriptRoot
     }
 
-    $allTextFiles      = Get-TextFilesList $projectRoot
+    $allTextFiles      = Get-TextFilesList -Root $projectRoot
     $unicodeFilesCount = 0
     $totalTabsCount    = 0
     foreach ($textFile in $allTextFiles) {
-        if (Test-FileUnicode $textFile) {
+        if (Test-FileUnicode -FileInfo $textFile) {
             $unicodeFilesCount++
             Write-Warning (
                 "File $($textFile.FullName) contains 0x00 bytes." +
@@ -24,7 +24,7 @@ BeforeAll {
         $unicodeFilesCount | Should -Be 0
 
         $fileName = $textFile.FullName
-        (Get-Content $fileName -Raw) | Select-String "`t" | Foreach-Object {
+        (Get-Content -Path $fileName -Raw) | Select-String -Pattern "`t" | Foreach-Object {
             Write-Warning (
                 "There are tabs in $fileName." +
                 ' Use Fixer "Get-TextFilesList `$pwd | ConvertTo-SpaceIndentation".'

tests/MetaFixers.psm1

@@ -27,6 +27,7 @@ function ConvertTo-UTF8 {
     [OutputType([void])]
     param(
         [Parameter(Mandatory = $true, ValueFromPipeline = $true)]
+        [ValidateNotNull()]
         [System.IO.FileInfo]$FileInfo
     )
 
@@ -56,6 +57,7 @@ function ConvertTo-SpaceIndentation {
     [OutputType([void])]
     param(
         [Parameter(Mandatory = $true, ValueFromPipeline = $true)]
+        [ValidateNotNull()]
         [System.IO.FileInfo]$FileInfo
     )
 
@@ -85,6 +87,7 @@ function Get-TextFilesList {
     [OutputType([System.IO.FileInfo])]
     param(
         [Parameter(Mandatory = $true, ValueFromPipeline = $true)]
+        [ValidateNotNullOrEmpty()]
         [string]$Root
     )
 
@@ -159,10 +162,11 @@ function Get-UnicodeFilesList {
     [OutputType([System.IO.FileInfo])]
     param(
         [Parameter(Mandatory = $true)]
+        [ValidateNotNullOrEmpty()]
         [string]$Root
     )
 
     $root | Get-TextFilesList | Where-Object {
-        Test-FileUnicode $_
+        Test-FileUnicode -FileInfo $_
     }
 }