Preserve alias corrections for executable commands in fallback DSC ASTs (#2284)

* Initial plan

* Fix fallback DSC resource detection

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/AvoidAlias.cs

@@ -207,7 +207,9 @@ private bool IsDscResourceDeclaration(CommandAst cmdAst)
                 if (parent is FunctionDefinitionAst
                     || parent is HashtableAst
                     || parent is AssignmentStatementAst
-                    || parent is ParenExpressionAst)
+                    || parent is ParenExpressionAst
+                    || parent is SubExpressionAst
+                    || parent is ArrayExpressionAst)
                 {
                     return false;
                 }
@@ -228,7 +230,9 @@ private bool IsDscResourceDeclaration(CommandAst cmdAst)
                 if (parent is FunctionDefinitionAst
                     || parent is HashtableAst
                     || parent is AssignmentStatementAst
-                    || parent is ParenExpressionAst)
+                    || parent is ParenExpressionAst
+                    || parent is SubExpressionAst
+                    || parent is ArrayExpressionAst)
                 {
                     return false;
                 }
@@ -305,14 +309,16 @@ private ScriptBlockExpressionAst GetDscResourceBody(CommandAst cmdAst)
             if (cmdAst.InvocationOperator != TokenKind.Unknown
                 || cmdAst.CommandElements.Count < 2
                 || !(cmdAst.CommandElements[1] is ExpressionAst)
-                || cmdAst.CommandElements[1].Extent.Text == "=")
+                || cmdAst.CommandElements[1].Extent.Text == "="
+                || cmdAst.Redirections.Count != 0)
             {
                 return null;
             }
 
             if (!(cmdAst.Parent is PipelineAst commandPipeline)
                 || commandPipeline.PipelineElements.Count != 1
-                || commandPipeline.PipelineElements[0] != cmdAst)
+                || commandPipeline.PipelineElements[0] != cmdAst
+                || !(commandPipeline.Parent is NamedBlockAst || commandPipeline.Parent is StatementBlockAst))
             {
                 return null;
             }

Tests/Rules/AvoidUsingAlias.tests.ps1

@@ -201,6 +201,37 @@ Configuration PackageTest {
             $violations[5].Extent.Text | Should -Be 'Verb'
             $violations[6].Extent.Text | Should -Be 'gci'
         }
+
+        It "does not mistake executable pipelines for DSC resources in fallback configuration ASTs" {
+            $target = @'
+{
+    Write-Output $(Verb Argument {})
+    @(Verb Argument {})
+    Verb Argument {} > $null
+    if (Verb Argument {}) {}
+    return Verb Argument {}
+    if ($true) {
+        Verb SameLineResource {}
+        Verb NextLineResource
+        {
+        }
+    }
+}
+'@
+            $ast = [System.Management.Automation.Language.Parser]::ParseInput($target, [ref]$null, [ref]$null)
+            $body = $ast.EndBlock.Statements[0].PipelineElements[0].Expression.Copy()
+            $configuration = [System.Management.Automation.Language.ConfigurationDefinitionAst]::new(
+                $ast.Extent, $body, 'Resource',
+                [System.Management.Automation.Language.StringConstantExpressionAst]::new($ast.Extent, 'Test', 'BareWord'))
+            $rule = [Microsoft.Windows.PowerShell.ScriptAnalyzer.BuiltinRules.AvoidAlias]::new()
+
+            $violations = @($rule.AnalyzeScript($configuration, $null))
+
+            $violations.Count | Should -Be 5
+            $violations | ForEach-Object {
+                $_.SuggestedCorrections[0].Text | Should -Be 'Get-Verb'
+            }
+        }
     }
 
     Context "Settings file provides allowlist" {