PSAvoidTrailingWhitespace: Rule not applied when using formatter + si…

…ngle character lines with trailing whitespace are truncated (#1993) * Formatter: Added PSAvoidTrailingWhitespace to the list of rules considered by the formatter * Rules/AvoidTrailingWhitespace: Fixed issue where lines with a single character, followed by multiple white-spaces were truncated when fixed/formatted * Tests/Rules/AvoidTrailingWhitespace: Added test for usage of Invoke-Formatter with PSAvoidTrailingWhitespace and also checking that single-character lines that have trailing whitespace are not removed --------- Co-authored-by: Christoph Bergmeister <[email protected]>
PowerShell · Feb 25, 2025 · d6eb35e · d6eb35e
1 parent 4f0c07a
commit d6eb35e
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Showing 3 changed files with 27 additions and 1 deletion.
diff --git a/Engine/Formatter.cs b/Engine/Formatter.cs
@@ -47,6 +47,7 @@ public static string Format<TCmdlet>(
                 "PSAvoidUsingDoubleQuotesForConstantString",
                 "PSAvoidSemicolonsAsLineTerminators",
                 "PSAvoidExclaimOperator",
+                "PSAvoidTrailingWhitespace",
             };
 
             var text = new EditableText(scriptDefinition);

diff --git a/Rules/AvoidTrailingWhitespace.cs b/Rules/AvoidTrailingWhitespace.cs
@@ -54,7 +54,7 @@ public IEnumerable<DiagnosticRecord> AnalyzeScript(Ast ast, string fileName)
                 }
 
                 int startColumnOfTrailingWhitespace = 1;
-                for (int i = line.Length - 2; i > 0; i--)
+                for (int i = line.Length - 2; i >= 0; i--)
                 {
                     if (line[i] != ' ' && line[i] != '\t')
                     {

diff --git a/Tests/Rules/AvoidTrailingWhitespace.tests.ps1 b/Tests/Rules/AvoidTrailingWhitespace.tests.ps1
@@ -9,6 +9,9 @@ BeforeAll {
 
     $settings = @{
         IncludeRules = @($ruleName)
+        Rules = @{
+            $ruleName = @{}
+        }
     }
 }
 
@@ -34,4 +37,26 @@ Describe "AvoidTrailingWhitespace" {
         $violations = Invoke-ScriptAnalyzer -ScriptDefinition $def -Settings $settings
         Test-CorrectionExtentFromContent $def $violations 1 $Whitespace ''
     }
+
+    It 'Should be used by Invoke-Formatter, when in settings, replacing trailing <Type>' -TestCases $testCases {
+        param (
+            [string] $Whitespace
+        )
+        # Test also guards against regression where single-character lines, with trailing whitespace
+        # would be removed entirely. See issues #1757, #1992
+        $def = @"
+Function Get-Example {
+    'Example'$Whitespace
+}$Whitespace
+"@
+
+        $expected = @"
+Function Get-Example {
+    'Example'
 }
+"@
+        $formatted = Invoke-Formatter -ScriptDefinition $def -Settings $settings
+        $formatted | Should -Be $expected
+    }
+
+}