From fef8514b84b4bcffa8708340e2f8119eab7f9d38 Mon Sep 17 00:00:00 2001
From: Jack Tracey <jack@jacktracey.co.uk>
Date: Mon, 31 Jul 2023 12:07:42 +0100
Subject: [PATCH] add edit-lineendings function

---
 src/ALZ/ALZ.psd1                              |  1 +
 src/ALZ/Public/Edit-LineEnding.ps1            | 41 +++++++++
 .../Unit/Public/Edit-LineEnding.Tests.ps1     | 89 +++++++++++++++++++
 3 files changed, 131 insertions(+)
 create mode 100644 src/ALZ/Public/Edit-LineEnding.ps1
 create mode 100644 src/Tests/Unit/Public/Edit-LineEnding.Tests.ps1

diff --git a/src/ALZ/ALZ.psd1 b/src/ALZ/ALZ.psd1
index c65cc0d8..d1fe889f 100644
--- a/src/ALZ/ALZ.psd1
+++ b/src/ALZ/ALZ.psd1
@@ -73,6 +73,7 @@
         'Get-ALZGithubRelease'
         'New-ALZEnvironment'
         'Test-ALZRequirement'
+        'Edit-LineEnding'
     )
 
     # Cmdlets to export from this module, for best performance, do not use wildcards and do not delete the entry, use an empty array if there are no cmdlets to export.
diff --git a/src/ALZ/Public/Edit-LineEnding.ps1 b/src/ALZ/Public/Edit-LineEnding.ps1
new file mode 100644
index 00000000..52d8a84f
--- /dev/null
+++ b/src/ALZ/Public/Edit-LineEnding.ps1
@@ -0,0 +1,41 @@
+enum LineEndingTypes {
+    Darwin
+    Unix
+    Win
+}
+
+function Edit-LineEnding {
+    [CmdletBinding(SupportsShouldProcess = $true)]
+    [OutputType([String[]])]
+    param (
+        [Parameter(ValueFromPipeline = $true)]
+        [String[]]$InputText,
+        [Parameter()][LineEndingTypes]$LineEnding = "Unix"
+    )
+
+    Begin {
+
+        Switch ("$LineEnding".ToLower()) {
+            "darwin" { $eol = "`r" }
+            "unix" { $eol = "`n" }
+            "win" { $eol = "`r`n" }
+        }
+
+    }
+
+    Process {
+
+        [String[]]$outputText += $InputText |
+            ForEach-Object { $_ -replace "`r`n", "`n" } |
+            ForEach-Object { $_ -replace "`r", "`n" } |
+            ForEach-Object { $_ -replace "`n", "$eol" }
+
+    }
+
+    End {
+
+        return $outputText
+
+    }
+
+}
\ No newline at end of file
diff --git a/src/Tests/Unit/Public/Edit-LineEnding.Tests.ps1 b/src/Tests/Unit/Public/Edit-LineEnding.Tests.ps1
new file mode 100644
index 00000000..741069d1
--- /dev/null
+++ b/src/Tests/Unit/Public/Edit-LineEnding.Tests.ps1
@@ -0,0 +1,89 @@
+#-------------------------------------------------------------------------
+Set-Location -Path $PSScriptRoot
+#-------------------------------------------------------------------------
+$ModuleName = 'ALZ'
+$PathToManifest = [System.IO.Path]::Combine('..', '..', '..', $ModuleName, "$ModuleName.psd1")
+#-------------------------------------------------------------------------
+if (Get-Module -Name $ModuleName -ErrorAction 'SilentlyContinue') {
+    #if the module is already in memory, remove it
+    Remove-Module -Name $ModuleName -Force
+}
+Import-Module $PathToManifest -Force
+#-------------------------------------------------------------------------
+
+InModuleScope 'ALZ' {
+    Describe "Edit-LineEnding" {
+        BeforeAll {
+            $WarningPreference = 'SilentlyContinue'
+            $ErrorActionPreference = 'SilentlyContinue'
+        }
+        Context "When converting to Unix line endings" {
+            It "Converts Windows line endings to Unix" {
+                $inputText = "Hello`r`nWorld`r`n"
+                $expectedOutput = "Hello`nWorld`n"
+                $result = Edit-LineEnding -InputText $inputText -LineEnding Unix
+                $result | Should -Be $expectedOutput
+            }
+
+            It "Converts mixed line endings to Unix" {
+                $inputText = "Hello`rWorld`n"
+                $expectedOutput = "Hello`nWorld`n"
+                $result = Edit-LineEnding -InputText $inputText -LineEnding Unix
+                $result | Should -Be $expectedOutput
+            }
+
+            It "Does not modify Unix line endings" {
+                $inputText = "Hello`nWorld`n"
+                $expectedOutput = "Hello`nWorld`n"
+                $result = Edit-LineEnding -InputText $inputText -LineEnding Unix
+                $result | Should -Be $expectedOutput
+            }
+        }
+
+        Context "When converting to Windows line endings" {
+            It "Converts Unix line endings to Windows" {
+                $inputText = "Hello`nWorld`n"
+                $expectedOutput = "Hello`r`nWorld`r`n"
+                $result = Edit-LineEnding -InputText $inputText -LineEnding Win
+                $result | Should -Be $expectedOutput
+            }
+
+            It "Converts mixed line endings to Windows" {
+                $inputText = "Hello`rWorld`n"
+                $expectedOutput = "Hello`r`nWorld`r`n"
+                $result = Edit-LineEnding -InputText $inputText -LineEnding Win
+                $result | Should -Be $expectedOutput
+            }
+
+            It "Does not modify Windows line endings" {
+                $inputText = "Hello`r`nWorld`r`n"
+                $expectedOutput = "Hello`r`nWorld`r`n"
+                $result = Edit-LineEnding -InputText $inputText -LineEnding Win
+                $result | Should -Be $expectedOutput
+            }
+        }
+
+        Context "When converting to Darwin line endings" {
+            It "Converts Unix line endings to Darwin" {
+                $inputText = "Hello`nWorld`n"
+                $expectedOutput = "Hello`rWorld`r"
+                $result = Edit-LineEnding -InputText $inputText -LineEnding Darwin
+                $result | Should -Be $expectedOutput
+            }
+
+            It "Converts mixed line endings to Darwin" {
+                $inputText = "Hello`rWorld`n"
+                $expectedOutput = "Hello`rWorld`r"
+                $result = Edit-LineEnding -InputText $inputText -LineEnding Darwin
+                $result | Should -Be $expectedOutput
+            }
+
+            It "Does not modify Darwin line endings" {
+                $inputText = "Hello`rWorld`r"
+                $expectedOutput = "Hello`rWorld`r"
+                $result = Edit-LineEnding -InputText $inputText -LineEnding Darwin
+                $result | Should -Be $expectedOutput
+            }
+        }
+    }
+}
\ No newline at end of file