Merge pull request #390 from PowerShell/HardCodedComputerNameRuleFixBranch

Added localhost exceptions for HardCodedComputerName Rule

Author: raghushantha

Rules/AvoidUsingComputerNameHardcoded.cs

@@ -15,6 +15,8 @@
 using Microsoft.Windows.PowerShell.ScriptAnalyzer.Generic;
 using System.ComponentModel.Composition;
 using System.Globalization;
+using System.Collections.Generic;
+using System.Linq;
 
 namespace Microsoft.Windows.PowerShell.ScriptAnalyzer.BuiltinRules
 {
@@ -48,7 +50,23 @@ 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;
+                    List<string> localhostRepresentations = new List<string> { "localhost", ".", "::1", "127.0.0.1" };
+                    Ast computerNameArgument = GetComputerNameArg(CmdAst, cmdParamAst.Extent.StartOffset);                                        
+
+                    if (null != computerNameArgument)
+                    {
+                        if (!localhostRepresentations.Contains(computerNameArgument.Extent.Text.ToLower()))
+                        {
+                            return computerNameArgument is ConstantExpressionAst;
+                        }
+
+                        return false;
+                    }
+                    
+                    if (null != cmdParamAst.Argument && !localhostRepresentations.Contains(cmdParamAst.Argument.ToString().Replace("\"", "").Replace("'", "").ToLower()))
+                    {
+                        return cmdParamAst.Argument is ConstantExpressionAst;
+                    }
                 }
             }
 

Tests/Rules/AvoidUsingComputerNameHardcodedNoViolations.ps1

@@ -1,2 +1,10 @@
 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
+Invoke-Command -ComputerName:'localhost'
+Invoke-Command -ComputerName:"."
+Invoke-Command -ComputerName:'::1'
+Invoke-Command -ComputerName:"127.0.0.1"