Added localhost exceptions for HardCodedComputerName Rule

Author: raghushantha

Rules/AvoidUsingComputerNameHardcoded.cs

@@ -15,6 +15,7 @@
 using Microsoft.Windows.PowerShell.ScriptAnalyzer.Generic;
 using System.ComponentModel.Composition;
 using System.Globalization;
+using System.Collections.Generic;
 
 namespace Microsoft.Windows.PowerShell.ScriptAnalyzer.BuiltinRules
 {
@@ -48,7 +49,12 @@ public override bool ParameterCondition(CommandAst CmdAst, CommandElementAst CeA
 
                 if (String.Equals(cmdParamAst.ParameterName, "computername", StringComparison.OrdinalIgnoreCase))
                 {
-                    return cmdParamAst.Argument is ConstantExpressionAst || GetComputerNameArg(CmdAst, cmdParamAst.Extent.StartOffset) is ConstantExpressionAst;
+                    Ast computerNameArgument = GetComputerNameArg(CmdAst, cmdParamAst.Extent.StartOffset);
+                    List<string> localhostExceptions = new List<string>{ "localhost", ".", "::1", "127.0.0.1" };
+                    if ((null != computerNameArgument) && (!localhostExceptions.Contains(computerNameArgument.Extent.Text)))
+                    {
+                        return cmdParamAst.Argument is ConstantExpressionAst || computerNameArgument is ConstantExpressionAst;
+                    }
                 }
             }
 

Tests/Rules/AvoidUsingComputerNameHardcodedNoViolations.ps1

@@ -1,2 +1,6 @@
 Invoke-Command -ComputerName $comp
-Invoke-Command -ComputerName $env:COMPUTERNAME
+Invoke-Command -ComputerName $env:COMPUTERNAME
+Invoke-Command -ComputerName localhost
+Invoke-Command -ComputerName .
+Invoke-Command -ComputerName ::1
+Invoke-Command -ComputerName 127.0.0.1