Extract SetModuleContent to wrap reading and joining into a module

Author: Jaykul

Source/Private/SetModuleContent.ps1

@@ -0,0 +1,66 @@
+function SetModuleContent {
+    <#
+        .SYNOPSIS
+            A wrapper for Set-Content that handles arrays of file paths
+        .DESCRIPTION
+            The implementation here is strongly dependent on Build-Module doing the right thing
+            Build-Module can optionally pass a PREFIX or SUFFIX, but otherwise only passes files
+
+            Because of that, SetModuleContent doesn't test for that
+
+            The goal here is to pretend this is a pipeline, for the sake of memory and file IO
+    #>
+    [CmdletBinding()]
+    param(
+        # Where to write the joined output
+        [Parameter(Position=0, Mandatory)]
+        [string]$OutputPath,
+
+        # Input files, the scripts that will be copied to the output path
+        # The FIRST and LAST items can be text content instead of file paths.
+        [Parameter(Mandatory, ValueFromPipeline, ValueFromPipelineByPropertyName)]
+        [Alias("PSPath", "FullName")]
+        [string[]]$SourceFile,
+
+        # The working directory (allows relative paths for other values)
+        [string]$WorkingDirectory = $pwd,
+
+        # The encoding defaults to UTF8 (or UTF8NoBom on Core)
+        [Parameter(DontShow)]
+        [string]$Encoding = $(if($IsCoreCLR) { "UTF8NoBom" } else { "UTF8" })
+    )
+    begin {
+        Push-Location $WorkingDirectory -StackName SetModuleContent
+        $ContentStarted = $false # There has been no content yet
+
+        # Create a proxy command style scriptblock for Set-Content to keep the file handle open
+        $SetContentCmd = $ExecutionContext.InvokeCommand.GetCommand('Microsoft.PowerShell.Management\Set-Content', [System.Management.Automation.CommandTypes]::Cmdlet)
+        $SetContent = {& $SetContentCmd -Path $OutputPath -Encoding $Encoding }.GetSteppablePipeline($myInvocation.CommandOrigin)
+        $SetContent.Begin($true)
+    }
+    process  {
+        foreach($file in $SourceFile) {
+            if($SourceName = Resolve-Path $file -Relative -ErrorAction SilentlyContinue) {
+                Write-Verbose "Adding $SourceName"
+                $SetContent.Process("#Region '$SourceName' 0")
+                Get-Content $SourceName -OutVariable source | ForEach-Object { $SetContent.Process($_) }
+                $SetContent.Process("#EndRegion '$SourceName' $($Source.Count)")
+            } else {
+                if(!$ContentStarted) {
+                    $SetContent.Process("#Region 'PREFIX' 0")
+                    $SetContent.Process($file)
+                    $SetContent.Process("#EndRegion 'PREFIX'")
+                    $ContentStarted = $true
+                } else {
+                    $SetContent.Process("#Region 'SUFFIX' 0")
+                    $SetContent.Process($file)
+                    $SetContent.Process("#EndRegion 'SUFFIX'")
+                }
+            }
+        }
+    }
+    end {
+        $SetContent.End()
+        Pop-Location -StackName SetModuleContent
+    }
+}