PSUseConsistentIndentation flattens the indentation of commented-out code

Summary

PSUseConsistentIndentation rewrites the whitespace before each comment's #, aligning every comment line in a block to the block indentation. When a run of comments is commented-out code (where the nested structure is expressed by the indentation before #), the rule flattens it, so the structure is lost. Whitespace after the # is preserved, so the two styles behave differently:

# preserved - the extra indentation is after the '#'
	# if ($b) {
	#     doThing
	# }

# flattened - the extra indentation is before the '#'
	# if ($b) {
		# doThing
	# }

Steps to reproduce

Only the one rule is enabled:

$settings = @{
	IncludeRules = @('PSUseConsistentIndentation')
	Rules        = @{
		PSUseConsistentIndentation = @{ Enable = $true; IndentationSize = 4; PipelineIndentation = 'NoIndentation'; Kind = 'tab' }
	}
}

Input:

if ($a) {
	# if ($b) {
		# doThing
	# }
}

Actual (Invoke-Formatter -ScriptDefinition $code -Settings $settings):

if ($a) {
	# if ($b) {
	# doThing
	# }
}

Expected: the commented-out block keeps its relative indentation (at most the whole comment run may be shifted to the code indentation).

The same happens with Kind = 'space' and when there is real code after the comment run.

Environment

• PSScriptAnalyzer 1.25.0
• PowerShell 7.6.6 on Windows

Why it matters

Commenting out a block is a common way to keep code around; flattening the indentation makes the commented-out block unreadable. Tooling that encodes directives as comments (e.g. sources that are uncommented by an external preprocessor) also relies on the indentation before # being preserved.

Related: #2151 asks for an ignore-range directive, but this is about the default behaviour of the indentation rule on ordinary comment runs.

Start by locating the PSUseConsistentIndentation rule and its formatter tests, then reproduce the issue with Invoke-Formatter using the settings and input shown here. Add coverage for nested commented-out code with both tab and space indentation, and confirm that the relative indentation before # is preserved without breaking runs containing real code.