Preserve relative indentation in comment runs (#2236)

* Initial plan

* Preserve indentation across comment runs

Co-authored-by: bergmeister <9250262+bergmeister@users.noreply.github.com>

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: bergmeister <9250262+bergmeister@users.noreply.github.com>

Author: Copilot

Rules/UseConsistentIndentation.cs

@@ -360,8 +360,21 @@ private static int GetCommentRunIndentationOffset(Token[] tokens, int tokenIndex
                 precedingIndex--;
             }
 
+            int leastIndentedColumn = tokens[firstCommentIndex].Extent.StartColumnNumber;
+            for (int nextCommentIndex = firstCommentIndex + 2;
+                nextCommentIndex < tokens.Length &&
+                    tokens[nextCommentIndex - 1].Kind == TokenKind.NewLine &&
+                    tokens[nextCommentIndex].Kind == TokenKind.Comment &&
+                    tokens[nextCommentIndex].Extent.StartLineNumber == tokens[nextCommentIndex - 2].Extent.EndLineNumber + 1;
+                nextCommentIndex += 2)
+            {
+                leastIndentedColumn = Math.Min(
+                    leastIndentedColumn,
+                    tokens[nextCommentIndex].Extent.StartColumnNumber);
+            }
+
             return tokens[tokenIndex].Extent.StartColumnNumber -
-                tokens[firstCommentIndex].Extent.StartColumnNumber;
+                leastIndentedColumn;
         }
 
         /// <summary>

Tests/Rules/UseConsistentIndentation.tests.ps1

@@ -253,6 +253,22 @@ function foo {
             Invoke-Formatter -ScriptDefinition $scriptDefinition -Settings $settings |
                 Should -Be $expectedScriptDefinition
         }
+
+        It 'Should preserve indentation when the first comment is not the least-indented with <Kind> indentation' -TestCases @(
+            @{ Kind = 'space'; Indentation = '    ' }
+            @{ Kind = 'tab'; Indentation = "`t" }
+        ) {
+            param([string] $Kind, [string] $Indentation)
+            $scriptDefinition = @(
+                "$Indentation# inner"
+                '# outer'
+            ) -join "`n"
+            $settings.Rules.PSUseConsistentIndentation.Kind = $Kind
+            $settings.Rules.PSUseConsistentIndentation.PipelineIndentation = 'NoIndentation'
+
+            Invoke-Formatter -ScriptDefinition $scriptDefinition -Settings $settings |
+                Should -Be $scriptDefinition
+        }
     }
 
     Context "When a multi-line command is given" {