From 1e78842e0a11a56ff0b6abe282f40072d58e3b31 Mon Sep 17 00:00:00 2001
From: Yuting Chen <yutch@microsoft.com>
Date: Thu, 21 May 2015 15:25:52 -0700
Subject: [PATCH 1/2] Add check for builtin variables for GlobalVar rule

---
 Engine/Helper.cs                                | 17 +++++++++++++++++
 Rules/AvoidGlobalVars.cs                        |  2 +-
 Tests/Rules/AvoidGlobalOrUnitializedVars.ps1    |  5 ++++-
 ...AvoidGlobalOrUnitializedVarsNoViolations.ps1 | 14 +++++---------
 4 files changed, 27 insertions(+), 11 deletions(-)

diff --git a/Engine/Helper.cs b/Engine/Helper.cs
index 8864ac136..92e8ed358 100644
--- a/Engine/Helper.cs
+++ b/Engine/Helper.cs
@@ -494,6 +494,23 @@ public bool IsVariableGlobalOrEnvironment(VariableExpressionAst varAst, Ast ast)
             return VariableAnalysisDictionary[ast].IsGlobalOrEnvironment(varAst);
         }
 
+
+        /// <summary>
+        /// Checks whether a variable is a built-in variable.
+        /// </summary>
+        /// <param name="ast"></param>
+        /// <returns></returns>
+        public bool IsVariableGlobal(VariableExpressionAst varAst)
+        {
+            if (varAst.VariablePath.IsGlobal)
+            {
+                string varName = varAst.VariablePath.UserPath.Remove(varAst.VariablePath.UserPath.IndexOf("global:", StringComparison.OrdinalIgnoreCase), "global:".Length);
+                return !SpecialVars.InitializedVariables.Contains(varName, StringComparer.OrdinalIgnoreCase);
+            }
+            return false;
+        }
+
+
         /// <summary>
         /// Checks whether all the code path of ast returns.
         /// Runs InitializeVariableAnalysis before calling this method
diff --git a/Rules/AvoidGlobalVars.cs b/Rules/AvoidGlobalVars.cs
index 6da1cdb91..109da5ee5 100644
--- a/Rules/AvoidGlobalVars.cs
+++ b/Rules/AvoidGlobalVars.cs
@@ -41,7 +41,7 @@ public IEnumerable<DiagnosticRecord> AnalyzeScript(Ast ast, string fileName)
             {
                 foreach (VariableExpressionAst varAst in varAsts)
                 {
-                    if (varAst.VariablePath.IsGlobal)
+                    if (Helper.Instance.IsVariableGlobal(varAst))
                     {
                         yield return
                             new DiagnosticRecord(
diff --git a/Tests/Rules/AvoidGlobalOrUnitializedVars.ps1 b/Tests/Rules/AvoidGlobalOrUnitializedVars.ps1
index ef6988ad9..e606404f3 100644
--- a/Tests/Rules/AvoidGlobalOrUnitializedVars.ps1
+++ b/Tests/Rules/AvoidGlobalOrUnitializedVars.ps1
@@ -1,4 +1,7 @@
-$Global:1 = "Globalization?"
+$Global:1 = "globalVar“
+$Global:DebugPreference
+
+
 
 function NotGlobal {
     $localVars = "Localization?"
diff --git a/Tests/Rules/AvoidGlobalOrUnitializedVarsNoViolations.ps1 b/Tests/Rules/AvoidGlobalOrUnitializedVarsNoViolations.ps1
index ea436bb4f..6a9ce8077 100644
--- a/Tests/Rules/AvoidGlobalOrUnitializedVarsNoViolations.ps1
+++ b/Tests/Rules/AvoidGlobalOrUnitializedVarsNoViolations.ps1
@@ -1,4 +1,7 @@
-function Test {
+$Global:DebugPreference
+
+
+function Test {
     $initialized = "Initialized"
     $noglobal = "local"
     $env:ShouldNotRaiseError
@@ -31,13 +34,6 @@ $proc[0]
 
 function Test-PreferenceVariable
 {
-    Param(
-        [switch]
-        $a,
-
-        [System.Management.Automation.SwitchParameter]
-        $b
-    )
 
    if (-not $PSBoundParameters.ContainsKey('Verbose')) {
        $VerbosePreference = $PSCmdlet.GetVariableValue('VerbosePreference') -as 

@@ -45,4 +41,4 @@ function Test-PreferenceVariable
         }
 
         $VerbosePreference
-}
\ No newline at end of file
+    }
\ No newline at end of file

From 7a1215a6b123c1ac2c1a225703e87a064d7bcb03 Mon Sep 17 00:00:00 2001
From: Yuting Chen <yutch@microsoft.com>
Date: Thu, 21 May 2015 15:54:57 -0700
Subject: [PATCH 2/2] Modify the comment

---
 Engine/Helper.cs | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/Engine/Helper.cs b/Engine/Helper.cs
index 92e8ed358..2f334241d 100644
--- a/Engine/Helper.cs
+++ b/Engine/Helper.cs
@@ -496,12 +496,13 @@ public bool IsVariableGlobalOrEnvironment(VariableExpressionAst varAst, Ast ast)
 
 
         /// <summary>
-        /// Checks whether a variable is a built-in variable.
+        /// Checks whether a variable is a global variable.
         /// </summary>
         /// <param name="ast"></param>
         /// <returns></returns>
         public bool IsVariableGlobal(VariableExpressionAst varAst)
         {
+            //We ignore the use of built-in variable as global variable
             if (varAst.VariablePath.IsGlobal)
             {
                 string varName = varAst.VariablePath.UserPath.Remove(varAst.VariablePath.UserPath.IndexOf("global:", StringComparison.OrdinalIgnoreCase), "global:".Length);