Convert Using fixer to a Script Generator

Author: Jaykul

Source/Private/MoveUsingStatements.ps1

@@ -0,0 +1,65 @@
+using namespace System.Management.Automation.Language
+
+function Move-UsingStatement {
+    <#
+        .SYNOPSIS
+            A Script Generator that commetnts out using statements and copies them to the top of the file
+        .DESCRIPTION
+            Move-UsingStatement supports having using statements repeated in multiple files that are merged by ModuleBuilder.
+            When all the files are merged together, the using statements from individual files
+            don't necessarily end up at the beginning of the PSM1, which creates Parsing Errors.
+
+            This function uses the AST to generate TextReplacements to:
+            1. Comment out the original using statements (to preserve line numbering)
+            2. Insert the using statements (conserving order, but removing duplicates) at the top of the script
+    #>
+    [CmdletBinding()]
+    [OutputType([TextReplacement])]
+    param(
+        # The AST of the original script module to refactor
+        [Parameter(Mandatory, ValueFromPipelineByPropertyName)]
+        [Alias("Ast")]
+        [Ast]$InputObject,
+
+        # Parser Errors from parsing the original script module
+        [Parameter(ValueFromPipelineByPropertyName)]
+        [AllowNull()]
+        [ParseError[]]$ParseErrors
+    )
+    process {
+        # Avoid modifying the file if there's no Parsing Error caused by Using Statements or other errors
+        if (!$ParseErrors.Where{ $_.ErrorId -eq 'UsingMustBeAtStartOfScript' }) {
+            Write-Debug "No using statement errors found."
+            return
+        } else {
+            # as decided https://github.com/PoshCode/ModuleBuilder/issues/96
+            Write-Debug "Parsing errors found. We'll still attempt to Move using statements."
+        }
+
+        # Find all Using statements including those non erroring (to conserve their order)
+        $UsingStatementExtents = $InputObject.FindAll(
+            { $Args[0] -is [System.Management.Automation.Language.UsingStatementAst] },
+            $false
+        ).Extent
+
+        # Edit the Script content by commenting out existing statements (conserving line numbering)
+        $StatementsToCopy = [System.Collections.Generic.HashSet[string]]::new([StringComparer]::OrdinalIgnoreCase)
+
+        foreach ($UsingSatement in $UsingStatementExtents) {
+            [TextReplacement]@{
+                StartOffset = $UsingSatement.StartOffset
+                EndOffset   = $UsingSatement.EndOffset
+                Text        = '# ' + $UsingSatement.Text
+            }
+            # Keep track of unique statements we'll need to insert at the top
+            $null = $StatementsToCopy.Add($UsingSatement.Text)
+        }
+        if ($StatementsToCopy.Count -gt 0) {
+            [TextReplacement]@{
+                StartOffset = 0
+                EndOffset   = 0
+                Text        = ($StatementsToCopy -join "`r`n")+ "`r`n"
+            }
+        }
+    }
+}

Source/Public/Move-UsingStatement.ps1

@@ -86,7 +86,7 @@ Describe "Build-Module" {
     Context "Testing" {
         BeforeAll {
             InModuleScope ModuleBuilder {
-                Mock MoveUsingStatements
+                Mock Move-UsingStatements
                 Mock SetModuleContent
             }
             Mock Update-Metadata
@@ -181,8 +181,8 @@ Describe "Build-Module" {
                 Assert-MockCalled ConvertToAst -Scope Context
             }
 
-            It "Should call MoveUsingStatements to move the using statements, just in case" {
-                Assert-MockCalled MoveUsingStatements -Parameter {
+            It "Should call Move-UsingStatement to move the using statements, just in case" {
+                Assert-MockCalled Move-UsingStatement -Parameter {
                     $AST.Extent.Text -eq "{ }"
                 } -Scope Context
             }