Normalize UTF-8 BOM Marks and ps1 Indention

.editorconfig

@@ -2,12 +2,18 @@
 root = true
 
 [*]
+charset = utf-8 # standardize on no BOM (except resx, see below)
 indent_style = tab
 indent_size = 4
 guidelines = 110
 tab_width = 4
 end_of_line = crlf
 
+# .net tooling writes the BOM to resx files on running dotnet build ILSpy.sln regardless,
+# so we should direct text editors to NOT change the file
+[*.resx]
+charset = utf-8-bom
+
 [*.il]
 indent_style = space
 indent_size = 2

BuildTools/bom-classify-encodings.ps1

@@ -0,0 +1,171 @@
+<#
+.SYNOPSIS
+Classify text files by encoding under the current subtree, respecting .gitignore.
+
+.DESCRIPTION
+Enumerates tracked files and untracked-but-not-ignored files (via Git) beneath
+PWD. Skips likely-binary files (NUL probe). Classifies remaining files as:
+	- 'utf8'          : valid UTF-8 (no BOM) or empty file
+	- 'utf8-with-bom' : starts with UTF-8 BOM (EF BB BF)
+	- 'other'         : text but not valid UTF-8 (e.g., UTF-16/ANSI)
+
+Outputs:
+	1) Relative paths of files classified as 'other'
+	2) A table by extension: UTF8 / UTF8-with-BOM / Other / Total
+
+Notes:
+	- Read-only: this script makes no changes.
+	- Requires Git and must be run inside a Git work tree.
+#>
+
+[CmdletBinding()]
+param()
+
+Set-StrictMode -Version Latest
+$ErrorActionPreference = 'Stop'
+
+# --- Git enumeration ---------------------------------------------------------
+function Assert-InGitWorkTree {
+	# Throws if not inside a Git work tree.
+	$inside = (& git rev-parse --is-inside-work-tree 2>$null).Trim()
+	if ($LASTEXITCODE -ne 0 -or $inside -ne 'true') {
+		throw 'Not in a Git work tree.'
+	}
+}
+
+function Get-GitFilesUnderPwd {
+	<#
+		Returns full paths to tracked + untracked-not-ignored files under PWD.
+	#>
+	Assert-InGitWorkTree
+
+	$repoRoot = (& git rev-parse --show-toplevel).Trim()
+	$pwdPath  = (Get-Location).Path
+
+	# cached (tracked) + others (untracked not ignored)
+	$nulSeparated = & git -C $repoRoot ls-files -z --cached --others --exclude-standard
+
+	$relativePaths = $nulSeparated.Split(
+		[char]0, [System.StringSplitOptions]::RemoveEmptyEntries)
+
+	foreach ($relPath in $relativePaths) {
+		$fullPath = Join-Path $repoRoot $relPath
+
+		# Only include files under the current subtree.
+		if ($fullPath.StartsWith($pwdPath,
+				[System.StringComparison]::OrdinalIgnoreCase)) {
+			if (Test-Path -LiteralPath $fullPath -PathType Leaf) { $fullPath }
+		}
+	}
+}
+
+# --- Probes ------------------------------------------------------------------
+function Test-ProbablyBinary {
+	# Heuristic: treat as binary if the first 8 KiB contains any NUL byte.
+	param([Parameter(Mandatory)][string]$Path)
+
+	try {
+		$stream = [System.IO.File]::Open($Path,'Open','Read','ReadWrite')
+		try {
+			$len = [int][Math]::Min(8192,$stream.Length)
+			if ($len -le 0) { return $false }
+
+			$buffer = [byte[]]::new($len)
+			[void]$stream.Read($buffer,0,$len)
+			return ($buffer -contains 0)
+		}
+		finally { $stream.Dispose() }
+	}
+	catch { return $false }
+}
+
+function Get-TextEncodingCategory {
+	# Returns 'utf8', 'utf8-with-bom', 'other', or $null for likely-binary.
+	param([Parameter(Mandatory)][string]$Path)
+
+	$stream = [System.IO.File]::Open($Path,'Open','Read','ReadWrite')
+	try {
+		$fileLength = $stream.Length
+		if ($fileLength -eq 0) { return 'utf8' }
+
+		# BOM check (EF BB BF)
+		$header = [byte[]]::new([Math]::Min(3,$fileLength))
+		[void]$stream.Read($header,0,$header.Length)
+		if ($header.Length -ge 3 -and
+				$header[0] -eq 0xEF -and $header[1] -eq 0xBB -and $header[2] -eq 0xBF) {
+			return 'utf8-with-bom'
+		}
+
+		# Quick binary probe before expensive decoding
+		$stream.Position = 0
+		$sampleLen = [int][Math]::Min(8192,$fileLength)
+		$sample = [byte[]]::new($sampleLen)
+		[void]$stream.Read($sample,0,$sampleLen)
+		if ($sample -contains 0) { return $null }
+	}
+	finally { $stream.Dispose() }
+
+	# Validate UTF-8 by decoding with throw-on-invalid option (no BOM).
+	try {
+		$bytes = [System.IO.File]::ReadAllBytes($Path)
+		$utf8 = [System.Text.UTF8Encoding]::new($false,$true)
+		[void]$utf8.GetString($bytes)
+		return 'utf8'
+	}
+	catch { return 'other' }
+}
+
+# --- Main --------------------------------------------------------------------
+$otherFiles  = @()
+$byExtension = @{}
+
+$allFiles = Get-GitFilesUnderPwd
+
+foreach ($fullPath in $allFiles) {
+	# Avoid decoding likely-binary files.
+	if (Test-ProbablyBinary $fullPath) { continue }
+
+	$category = Get-TextEncodingCategory $fullPath
+	if (-not $category) { continue }
+
+	$ext = [IO.Path]::GetExtension($fullPath).ToLower()
+	if (-not $byExtension.ContainsKey($ext)) {
+		$byExtension[$ext] = @{ 'utf8' = 0; 'utf8-with-bom' = 0; 'other' = 0 }
+	}
+
+	$byExtension[$ext][$category]++
+
+	if ($category -eq 'other') {
+		$otherFiles += (Resolve-Path -LiteralPath $fullPath -Relative)
+	}
+}
+
+# 1) Files in 'other'
+if ($otherFiles.Count -gt 0) {
+	'Files classified as ''other'':'
+	$otherFiles | Sort-Object | ForEach-Object { "  $_" }
+	''
+}
+
+# 2) Table by extension
+$rows = foreach ($kv in $byExtension.GetEnumerator()) {
+	$ext = if ($kv.Key) { $kv.Key } else { '[noext]' }
+	$u   = [int]$kv.Value['utf8']
+	$b   = [int]$kv.Value['utf8-with-bom']
+	$o   = [int]$kv.Value['other']
+
+	[PSCustomObject]@{
+		Extension       = $ext
+		UTF8            = $u
+		'UTF8-with-BOM' = $b
+		Other           = $o
+		Total           = $u + $b + $o
+	}
+}
+
+$rows |
+	Sort-Object -Property (
+			@{Expression='Total';Descending=$true},
+		@{Expression='Extension';Descending=$false}
+	) |
+	Format-Table -AutoSize

BuildTools/bom-strip.ps1

@@ -0,0 +1,208 @@
+<#
+.SYNOPSIS
+Strip UTF-8 BOM from selected text files under the current subtree, respecting
+.gitignore.
+
+.DESCRIPTION
+Enumerates tracked and untracked-but-not-ignored files under the current
+directory (via Git), filters to texty extensions and dotfiles, skips likely
+binary files (NUL probe), and removes a leading UTF-8 BOM (EF BB BF) in place.
+
+Refuses to run if there are uncommitted changes as a safeguard. Use -Force to override.
+Supports -WhatIf/-Confirm via ShouldProcess.
+#>
+
+[CmdletBinding(SupportsShouldProcess = $true, ConfirmImpact = 'Low')]
+param(
+	[switch]$Force
+)
+
+Set-StrictMode -Version Latest
+$ErrorActionPreference = 'Stop'
+
+# --- File sets (ILSpy) ------------------------------------------------------
+$Dotfiles = @(
+	'.gitignore', '.editorconfig', '.gitattributes', '.gitmodules',
+	'.tgitconfig', '.vsconfig'
+)
+
+$AllowedExts = @(
+	'.bat','.config','.cs','.csproj','.css','.filelist','.fs','.html','.il',
+	'.ipynb','.js','.json','.less','.manifest','.md','.projitems','.props',
+	'.ps1','.psd1','.ruleset','.shproj','.sln','.slnf','.svg','.template',
+	'.tt', '.txt','.vb','.vsct','.vsixlangpack','.wxl','.xaml','.xml','.xshd','.yml'
+)
+
+$IncludeNoExt = $true  # include names like LICENSE
+
+# --- Git checks / enumeration -----------------------------------------------
+function Assert-InGitWorkTree {
+	$inside = (& git rev-parse --is-inside-work-tree 2>$null).Trim()
+	if ($LASTEXITCODE -ne 0 -or $inside -ne 'true') {
+		throw 'Not in a Git work tree.'
+	}
+}
+
+function Assert-CleanWorkingTree {
+	if ($Force) { return }
+
+	$status = & git status --porcelain -z
+	if ($LASTEXITCODE -ne 0) { throw 'git status failed.' }
+
+	if (-not [string]::IsNullOrEmpty($status)) {
+		throw 'Working tree not clean. Commit/stash changes or use -Force.'
+	}
+}
+
+function Get-GitFilesUnderPwd {
+	Assert-InGitWorkTree
+
+	$repoRoot = (& git rev-parse --show-toplevel).Trim()
+	$pwdPath  = (Get-Location).Path
+
+	$tracked = & git -C $repoRoot ls-files -z
+	$others  = & git -C $repoRoot ls-files --others --exclude-standard -z
+
+	$allRel = ("$tracked$others").Split(
+		[char]0, [System.StringSplitOptions]::RemoveEmptyEntries)
+
+	foreach ($relPath in $allRel) {
+		$fullPath = Join-Path $repoRoot $relPath
+		if ($fullPath.StartsWith($pwdPath,
+				[System.StringComparison]::OrdinalIgnoreCase)) {
+			if (Test-Path -LiteralPath $fullPath -PathType Leaf) {
+				$fullPath
+			}
+		}
+	}
+}
+
+# --- Probes -----------------------------------------------------------------
+function Test-HasUtf8Bom {
+	param([Parameter(Mandatory)][string]$Path)
+
+	try {
+		$stream = [System.IO.File]::Open($Path,'Open','Read','ReadWrite')
+		try {
+			if ($stream.Length -lt 3) { return $false }
+
+			$header = [byte[]]::new(3)
+			[void]$stream.Read($header,0,3)
+
+			return ($header[0] -eq 0xEF -and
+							$header[1] -eq 0xBB -and
+							$header[2] -eq 0xBF)
+		}
+		finally {
+			$stream.Dispose()
+		}
+	}
+	catch { return $false }
+}
+
+function Test-ProbablyBinary {
+	# Binary if the first 8 KiB contains any NUL byte.
+	param([Parameter(Mandatory)][string]$Path)
+
+	try {
+		$stream = [System.IO.File]::Open($Path,'Open','Read','ReadWrite')
+		try {
+			$len = [int][Math]::Min(8192,$stream.Length)
+			if ($len -le 0) { return $false }
+
+			$buffer = [byte[]]::new($len)
+			[void]$stream.Read($buffer,0,$len)
+
+			return ($buffer -contains 0)
+		}
+		finally {
+			$stream.Dispose()
+		}
+	}
+	catch { return $false }
+}
+
+# --- Mutation ---------------------------------------------------------------
+function Remove-Utf8BomInPlace {
+	# Write the existing buffer from offset 3, no extra full-size allocation.
+	param([Parameter(Mandatory)][string]$Path)
+
+	$bytes = [System.IO.File]::ReadAllBytes($Path)
+	if ($bytes.Length -lt 3) { return $false }
+
+	if ($bytes[0] -ne 0xEF -or
+			$bytes[1] -ne 0xBB -or
+			$bytes[2] -ne 0xBF) {
+		return $false
+	}
+
+	$stream = [System.IO.File]::Open($Path,'Create','Write','ReadWrite')
+	try {
+		$stream.Write($bytes, 3, $bytes.Length - 3)
+		$stream.SetLength($bytes.Length - 3)
+	}
+	finally {
+		$stream.Dispose()
+	}
+
+	return $true
+}
+
+# --- Main -------------------------------------------------------------------
+Assert-InGitWorkTree
+Assert-CleanWorkingTree
+
+$allFiles = Get-GitFilesUnderPwd
+
+$targets = $allFiles | % {
+	$fileName = [IO.Path]::GetFileName($_)
+	$ext      = [IO.Path]::GetExtension($fileName)
+
+	$isDot    = $Dotfiles -contains $fileName
+	$isNoExt  = -not $fileName.Contains('.')
+
+	if ($isDot -or ($AllowedExts -contains $ext) -or
+			($IncludeNoExt -and $isNoExt -and -not $isDot)) {
+		$_
+	}
+}
+| ? { Test-HasUtf8Bom $_ }
+| ? { -not (Test-ProbablyBinary $_) }
+
+$changed        = 0
+$byExtension    = @{}
+$dotfileChanges = 0
+
+$targets | % {
+	$relative = Resolve-Path -LiteralPath $_ -Relative
+
+	if ($PSCmdlet.ShouldProcess($relative,'Strip UTF-8 BOM')) {
+		if (Remove-Utf8BomInPlace -Path $_) {
+			$changed++
+
+			$fileName = [IO.Path]::GetFileName($_)
+			if ($Dotfiles -contains $fileName) { $dotfileChanges++ }
+
+			$ext = [IO.Path]::GetExtension($fileName)
+			if (-not $byExtension.ContainsKey($ext)) { $byExtension[$ext] = 0 }
+			$byExtension[$ext]++
+
+			"stripped BOM: $relative"
+		}
+	}
+}
+
+"Done. Stripped BOM from $changed file(s)."
+
+if ($byExtension.Keys.Count -gt 0) {
+	""
+	"By extension:"
+	$byExtension.GetEnumerator() | Sort-Object Name | % {
+		$key = if ([string]::IsNullOrEmpty($_.Name)) { '[noext]' } else { $_.Name }
+		"  {0}: {1}" -f $key, $_.Value
+	}
+}
+
+if ($dotfileChanges -gt 0) {
+	"  [dotfiles]: $dotfileChanges"
+}