🩹 [Patch]: Add test to check that all PowerShell keywords are lower cased (#62)

## Description

- Add test to check that all PowerShell keywords are lower cased.
  - Fixes #19 

## Type of change

<!-- Use the check-boxes [x] on the options that are relevant. -->

- [ ] 📖 [Docs]
- [ ] 🪲 [Fix]
- [x] 🩹 [Patch]
- [ ] ⚠️ [Security fix]
- [ ] 🚀 [Feature]
- [ ] 🌟 [Breaking change]

## Checklist

<!-- Use the check-boxes [x] on the options that are relevant. -->

- [x] I have performed a self-review of my own code
- [x] I have commented my code, particularly in hard-to-understand areas

Author: MariusStorhaug

scripts/tests/PSModule/SourceCode.Tests.ps1

@@ -12,7 +12,7 @@ Param(
 )
 
 BeforeAll {
-    $scriptFiles = Get-ChildItem -Path $Path -Filter '*.ps1' -Recurse -File
+    $scriptFiles = Get-ChildItem -Path $Path -Include *.psm1, *.ps1 -Recurse -File
     $functionFiles = Get-ChildItem -Directory -Path $Path |
         Where-Object { $_.Name -in 'public', 'private' } |
         Get-ChildItem -Filter '*.ps1' -File
@@ -128,6 +128,28 @@ Describe 'PSModule - SourceCode tests' {
                 Should -BeNullOrEmpty -Because 'the script should not use ternary operations for compatability with PS 5.1 and below'
         }
 
+        It 'all powershell keywords are lowercase' {
+            $issues = @('')
+            $scriptFiles | ForEach-Object {
+                $filePath = $_.FullName
+                $relativePath = $filePath.Replace($Path, '').Trim('\').Trim('/')
+
+                $errors = $null
+                $tokens = $null
+                [System.Management.Automation.Language.Parser]::ParseFile($FilePath, [ref]$tokens, [ref]$errors)
+
+                foreach ($token in $tokens) {
+                    $keyword = $token.Text
+                    $lineNumber = $token.Extent.StartLineNumber
+                    $columnNumber = $token.Extent.StartColumnNumber
+                    if (($token.TokenFlags -match 'Keyword') -and ($keyword -cne $keyword.ToLower())) {
+                        $issues += " - $relativePath`:L$lineNumber`:C$columnNumber - $keyword"
+                    }
+                }
+            }
+            $issues -join [Environment]::NewLine | Should -BeNullOrEmpty -Because 'all powershell keywords should be lowercase'
+        }
+
         # It 'comment based doc block start is indented with 4 spaces' {}
         # It 'comment based doc is indented with 8 spaces' {}
         # It 'has synopsis for all functions' {}

tests/src/modules/OtherPSModule.psm1

@@ -1,4 +1,4 @@
-Function Get-OtherPSModule {
+function Get-OtherPSModule {
     <#
         .SYNOPSIS
         Performs tests on a module.

tests/src/private/Get-InternalPSModule.ps1

@@ -1,4 +1,4 @@
-Function Get-InternalPSModule {
+function Get-InternalPSModule {
     <#
         .SYNOPSIS
         Performs tests on a module.

tests/src/private/Set-InternalPSModule.ps1

@@ -1,4 +1,4 @@
-Function Set-InternalPSModule {
+function Set-InternalPSModule {
     <#
         .SYNOPSIS
         Performs tests on a module.

tests/srcWithManifest/modules/OtherPSModule.psm1

@@ -1,4 +1,4 @@
-Function Get-OtherPSModule {
+function Get-OtherPSModule {
     <#
         .SYNOPSIS
         Performs tests on a module.

tests/srcWithManifest/private/Get-InternalPSModule.ps1

@@ -1,4 +1,4 @@
-Function Get-InternalPSModule {
+function Get-InternalPSModule {
     <#
         .SYNOPSIS
         Performs tests on a module.

tests/srcWithManifest/private/Set-InternalPSModule.ps1

@@ -1,4 +1,4 @@
-Function Set-InternalPSModule {
+function Set-InternalPSModule {
     <#
         .SYNOPSIS
         Performs tests on a module.