From 9b23e1e1fedd22f63bab41f769dab42d022ae50b Mon Sep 17 00:00:00 2001
From: Ilya <darpa@yandex.ru>
Date: Wed, 18 Jan 2017 00:54:43 +0400
Subject: [PATCH] Fix error handling in parsing 'using' statement (#3007)

---
 .../engine/parser/Parser.cs                   | 10 ++++++--
 .../Classes/scripting.Classes.using.tests.ps1 | 23 +++++++++++++++++++
 2 files changed, 31 insertions(+), 2 deletions(-)

diff --git a/src/System.Management.Automation/engine/parser/Parser.cs b/src/System.Management.Automation/engine/parser/Parser.cs
index 92b0cc253f..6050538c39 100644
--- a/src/System.Management.Automation/engine/parser/Parser.cs
+++ b/src/System.Management.Automation/engine/parser/Parser.cs
@@ -4414,8 +4414,11 @@ namespace System.Management.Automation.Language
             {
                 case TokenKind.EndOfInput:
                 case TokenKind.NewLine:
-                // Example, using module ,FooBar
+                // Example: 'using module ,FooBar'
+                // GetCommandArgument will successfully return an argument for a unary array argument
+                // but we don't want to allow that syntax with a using statement.
                 case TokenKind.Comma:
+                case TokenKind.Semi:
                     {
                         ReportIncompleteInput(After(directiveToken), () => ParserStrings.MissingUsingItemName);
                         return new ErrorStatementAst(ExtentOf(usingToken, directiveToken));
@@ -4426,11 +4429,14 @@ namespace System.Management.Automation.Language
             if (itemAst == null)
             {
                 ReportError(itemToken.Extent, () => ParserStrings.InvalidValueForUsingItemName, itemToken.Text);
+                // ErrorRecovery: If there is no identifier, skip whole 'using' line
+                SyncOnError(true, TokenKind.Semi, TokenKind.NewLine);
+                return new ErrorStatementAst(ExtentOf(usingToken, itemToken.Extent));
             }
 
             if (!(itemAst is StringConstantExpressionAst) && (kind != UsingStatementKind.Module || !(itemAst is HashtableAst)))
             {
-                ReportError(ExtentOf(usingToken, ExtentFromFirstOf(itemAst, itemToken)), () => ParserStrings.InvalidValueForUsingItemName, itemAst.Extent.Text);
+                ReportError(ExtentFromFirstOf(itemAst, itemToken), () => ParserStrings.InvalidValueForUsingItemName, itemAst.Extent.Text);
                 return new ErrorStatementAst(ExtentOf(usingToken, ExtentFromFirstOf(itemAst, itemToken)));
             }
 
diff --git a/test/powershell/Language/Classes/scripting.Classes.using.tests.ps1 b/test/powershell/Language/Classes/scripting.Classes.using.tests.ps1
index 23806d5a43..fadbfee303 100644
--- a/test/powershell/Language/Classes/scripting.Classes.using.tests.ps1
+++ b/test/powershell/Language/Classes/scripting.Classes.using.tests.ps1
@@ -261,6 +261,29 @@ New-Object Foo
             $err[1].ErrorId | Should Be 'RequiresModuleInvalid'
         }
 
+        It "report an error when 'using module' terminating by NewLine" {
+            $err = Get-ParseResults "using module"
+            $err.Count | Should Be 1
+            $err[0].ErrorId | Should Be 'MissingUsingItemName'
+        }
+
+        It "report an error when 'using module' terminating by Semicolon" {
+            $err = Get-ParseResults "using module; $testvar=1"
+            $err.Count | Should Be 1
+            $err[0].ErrorId | Should Be 'MissingUsingItemName'
+        }
+
+        It "report an error when a value after 'using module' is a unallowed expression" {
+            $err = Get-ParseResults "using module )"
+            $err.Count | Should Be 1
+            $err[0].ErrorId | Should Be 'InvalidValueForUsingItemName'
+        }
+
+        It "report an error when a value after 'using module' is not a valid module name" {
+            $err = Get-ParseResults "using module 123"
+            $err.Count | Should Be 1
+            $err[0].ErrorId | Should Be 'InvalidValueForUsingItemName'
+        }
     }
 
     Context 'short name in case of name collision' {