Implemented more CoPilot suggestions

Author: iRon7

Rules/AvoidUsingNewObject.cs

@@ -19,11 +19,11 @@ namespace Microsoft.Windows.PowerShell.ScriptAnalyzer.BuiltinRules
 #endif
 
     /// <summary>
-    /// Rule that reports an warning when the New-Object cmdlet is used in a script.
+    /// Rule that reports a warning when the New-Object cmdlet is used in a script.
     /// The rule implements a correction that suggests using type-casting or type constructor.
     ///
     /// Note:
-    /// In most cases if there isn't an automatic correction isn't available,
+    /// In most cases if there isn't an automatic correction available,
     /// the rule won't report any violation either.
     /// This is because if there isn't an automatic correction available, it generally means
     /// that there isn't a simple type-casting or type constructor that can be used that would
@@ -63,8 +63,8 @@ public override IEnumerable<DiagnosticRecord> AnalyzeScript(Ast ast, string file
 
             IEnumerable<CommandAst> newObjectAsts = ast.FindAll(testAst =>
                 testAst is CommandAst cmdAst &&
-                cmdAst.GetCommandName() != null &&
-                cmdAst.GetCommandName().Equals("New-Object", StringComparison.OrdinalIgnoreCase),
+                (cmdAst.GetCommandName() as string) is string commandName &&
+                commandName.Equals("New-Object", StringComparison.OrdinalIgnoreCase),
                 true
             ).Cast<CommandAst>();
 
@@ -77,19 +77,24 @@ testAst is CommandAst cmdAst &&
                 // But not both, as that would mean there isn't a simple
                 // type initializer available as a replacement.
                 if (
-                    bindingResult.BoundParameters.Count == 2 &&
+                    bindingResult.BoundParameters.Count <= 2 &&
                     bindingResult.BoundParameters.TryGetValue("TypeName", out ParameterBindingResult asTypeName) &&
                     asTypeName.ConstantValue is string typeName
                 ) {
                     Boolean isProperty = bindingResult.BoundParameters.TryGetValue("Property", out ParameterBindingResult boundResult);
                     if (!isProperty)
                     {
                         Boolean isArgument = bindingResult.BoundParameters.TryGetValue("ArgumentList", out ParameterBindingResult argumentResult);
-                        if (isArgument) { boundResult = argumentResult; } else { continue; }
+                        if (isArgument) { boundResult = argumentResult; }
                     }
 
                     string correction = null;
-                    if (isProperty)
+                    if (boundResult == null)
+                    {
+                        // No `-Property` or `-ArgumentList` parameter was used, so we suggest a parameterless constructor call.
+                        correction = "[" + typeName + "]::new()";
+                    }
+                    else if (isProperty)
                     {
                         correction = "[" + typeName + "]" + boundResult.Value.Extent.Text;
                     }

Tests/Rules/AvoidUsingNewObject.tests.ps1

@@ -144,6 +144,19 @@ Describe "AvoidUsingNewObject" {
 
     Context 'Construct' {
 
+        It 'Empty string' {
+            $scriptDefinition = { $String = New-Object String }.ToString()
+            $violations = Invoke-ScriptAnalyzer -ScriptDefinition $scriptDefinition -Settings $Settings
+            $violations.Count                            | Should -Be 1
+            $violations.Severity                         | Should -Be Warning
+            $violations.Extent.Text                      | Should -Be 'New-Object String'
+            $violations.Message                          | Should -Be ($ruleMessage -f 'String')
+            $violations.RuleSuppressionID                | Should -Be 'String'
+            $violations.SuggestedCorrections.Text        | Should -Be '[String]::new()'
+            $violations.SuggestedCorrections.Text        | Should -Parse
+            $violations.SuggestedCorrections.Description | Should -Be ($correctionDescription -f 'String')
+        }
+
         It 'String ArgumentList ($Test)' {
             $scriptDefinition = { $String = New-Object -TypeName String -ArgumentList ($Test) }.ToString()
             $violations = Invoke-ScriptAnalyzer -ScriptDefinition $scriptDefinition -Settings $Settings
@@ -202,7 +215,7 @@ Describe "AvoidUsingNewObject" {
             $scriptDefinition = {
                 Write-Host New-Object String 123
             }.ToString()
-             $violations = Invoke-ScriptAnalyzer -ScriptDefinition $scriptDefinition -Settings $Settings
+            $violations = Invoke-ScriptAnalyzer -ScriptDefinition $scriptDefinition -Settings $Settings
             $violations | Should -BeNullOrEmpty
         }
 
@@ -267,7 +280,7 @@ Describe "AvoidUsingNewObject" {
             $violations.SuggestedCorrections.Text | Should -Parse
         }
 
-         It 'Double quoted string argument' {
+        It 'Double quoted string argument' {
             $scriptDefinition = { New-Object MyClass "Test" }.ToString()
             $violations = Invoke-ScriptAnalyzer -ScriptDefinition $scriptDefinition -Settings $Settings
             $violations.SuggestedCorrections.Text | Should -Be '[MyClass]"Test"'

docs/Rules/AvoidUsingNewObject.md

@@ -15,7 +15,7 @@ title: AvoidUsingNewObject
 ## Description
 
 Avoid using the `New-Object` cmdlet to create objects as it might perform poorly.
-Instead, use type initializer to construct or cast the intended object.
+Instead, use a type initializer to construct or cast the intended object.
 
 ## Example