Add support for static usings.

- Added special cases to the using statement parser to understand `@using static Foo`.
- Added several unit tests to validate the static using structure.
- Modified existing import code generation tests to validate several static usings.

#44

src/Microsoft.AspNet.Razor/Parser/CSharpCodeParser.Statements.cs

@@ -101,7 +101,7 @@ namespace Microsoft.AspNet.Razor.Parser
                 // using ( ==> Using Statement
                 UsingStatement(block);
             }
-            else if (At(CSharpSymbolType.Identifier))
+            else if (At(CSharpSymbolType.Identifier) || At(CSharpKeyword.Static))
             {
                 // using Identifier ==> Using Declaration
                 if (!topLevel)
@@ -126,31 +126,40 @@ namespace Microsoft.AspNet.Razor.Parser
             // Set block type to directive
             Context.CurrentBlock.Type = BlockType.Directive;
 
-            // Parse a type name
+            if (At(CSharpSymbolType.Identifier))
-            Assert(CSharpSymbolType.Identifier);
-            NamespaceOrTypeName();
-            IEnumerable<CSharpSymbol> ws = ReadWhile(IsSpacingToken(includeNewLines: true, includeComments: true));
-            if (At(CSharpSymbolType.Assign))
             {
-                // Alias
+                // non-static using
-                Accept(ws);
-                Assert(CSharpSymbolType.Assign);
-                AcceptAndMoveNext();
-
-                AcceptWhile(IsSpacingToken(includeNewLines: true, includeComments: true));
-
-                // One more namespace or type name
                 NamespaceOrTypeName();
+                var whitespace = ReadWhile(IsSpacingToken(includeNewLines: true, includeComments: true));
+                if (At(CSharpSymbolType.Assign))
+                {
+                    // Alias
+                    Accept(whitespace);
+                    Assert(CSharpSymbolType.Assign);
+                    AcceptAndMoveNext();
+
+                    AcceptWhile(IsSpacingToken(includeNewLines: true, includeComments: true));
+
+                    // One more namespace or type name
+                    NamespaceOrTypeName();
+                }
+                else
+                {
+                    PutCurrentBack();
+                    PutBack(whitespace);
+                }
             }
-            else
+            else if (At(CSharpKeyword.Static))
             {
-                PutCurrentBack();
+                // static using
-                PutBack(ws);
+                AcceptAndMoveNext();
+                AcceptWhile(IsSpacingToken(includeNewLines: false, includeComments: true));
+                NamespaceOrTypeName();
             }
 
             Span.EditHandler.AcceptedCharacters = AcceptedCharacters.AnyExceptNewline;
             Span.CodeGenerator = new AddImportCodeGenerator(
-                Span.GetContent(syms => syms.Skip(1)));
+                Span.GetContent(symbols => symbols.Skip(1)));
 
             // Optional ";"
             if (EnsureCurrent())

test/Microsoft.AspNet.Razor.Test/Generator/CSharpRazorCodeGeneratorTest.cs

@@ -176,8 +176,11 @@ namespace Microsoft.AspNet.Razor.Test.Generator
                 BuildLineMapping(1, 0, 1, 51, 3, 0, 15),
                 BuildLineMapping(19, 1, 1, 132, 9, 0, 32),
                 BuildLineMapping(54, 2, 1, 230, 15, 0, 12),
-                BuildLineMapping(99, 4, 772, 39, 29, 21),
+                BuildLineMapping(71, 4, 1, 308, 21, 0, 19),
-                BuildLineMapping(161, 5, 888, 44, 35, 20)
+                BuildLineMapping(93, 5, 1, 393, 27, 0, 27),
+                BuildLineMapping(123, 6, 1, 486, 33, 0, 41),
+                BuildLineMapping(197, 8, 1057, 57, 29, 21),
+                BuildLineMapping(259, 9, 1174, 62, 35, 20)
             });
         }
 

test/Microsoft.AspNet.Razor.Test/Parser/CSharp/CSharpStatementTest.cs

@@ -1,6 +1,7 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
+using System;
 using Microsoft.AspNet.Razor.Generator;
 using Microsoft.AspNet.Razor.Parser;
 using Microsoft.AspNet.Razor.Parser.SyntaxTree;
@@ -148,6 +149,53 @@ namespace Microsoft.AspNet.Razor.Test.Parser.CSharp
                                ));
         }
 
+        public static TheoryData StaticUsingData
+        {
+            get
+            {
+                var factory = SpanFactory.CreateCsHtml();
+                Func<string, string, DirectiveBlock> createUsing = (code, import) =>
+                    new DirectiveBlock(
+                        factory.CodeTransition(),
+                        factory.Code(code)
+                            .AsNamespaceImport(import)
+                            .Accepts(AcceptedCharacters.AnyExceptNewline));
+
+                // document, expectedResult
+                return new TheoryData<string, DirectiveBlock>
+                {
+                    { "@using static", createUsing("using static", " static") },
+                    { "@using static    ", createUsing("using static    ", " static    ") },
+                    { "@using         static    ", createUsing("using         static    ", "         static    ") },
+                    { "@using static System", createUsing("using static System", " static System") },
+                    {
+                        "@using static         System",
+                        createUsing("using static         System", " static         System")
+                    },
+                    {
+                        "@using static System.Console",
+                        createUsing("using static System.Console", " static System.Console")
+                    },
+                    {
+                        "@using static global::System.Console",
+                        createUsing("using static global::System.Console", " static global::System.Console")
+                    },
+                    {
+                        "@using   static   global::System.Console  ",
+                        createUsing("using   static   global::System.Console", "   static   global::System.Console")
+                    },
+                };
+            }
+        }
+
+        [Theory]
+        [MemberData(nameof(StaticUsingData))]
+        public void StaticUsingImport(string document, DirectiveBlock expectedResult)
+        {
+            // Act & Assert
+            ParseBlockTest(document, expectedResult);
+        }
+
         [Fact]
         public void UsingStatement()
         {

test/Microsoft.AspNet.Razor.Test/TestFiles/CodeGenerator/CS/Output/Imports.DesignTime.cs

@@ -15,6 +15,24 @@ using Foo = System.Text.Encoding
 #line 3 "Imports.cshtml"
 using System
 
+#line default
+#line hidden
+    ;
+#line 5 "Imports.cshtml"
+using static System
+
+#line default
+#line hidden
+    ;
+#line 6 "Imports.cshtml"
+using static System.Console
+
+#line default
+#line hidden
+    ;
+#line 7 "Imports.cshtml"
+using static global::System.Text.Encoding
+
 #line default
 #line hidden
     ;
@@ -36,12 +54,12 @@ using System
         #pragma warning disable 1998
         public override async Task ExecuteAsync()
         {
-#line 5 "Imports.cshtml"
+#line 9 "Imports.cshtml"
                        __o = typeof(Path).FullName;
 
 #line default
 #line hidden
-#line 6 "Imports.cshtml"
+#line 10 "Imports.cshtml"
                              __o = typeof(Foo).FullName;
 
 #line default

test/Microsoft.AspNet.Razor.Test/TestFiles/CodeGenerator/CS/Output/Imports.cs

@@ -1,4 +1,4 @@
-#pragma checksum "Imports.cshtml" "{ff1816ec-aa5e-4d10-87f7-6f4963833460}" "1b57def0ce2632d0f50d63dbdc5e0e719c202863"
+#pragma checksum "Imports.cshtml" "{ff1816ec-aa5e-4d10-87f7-6f4963833460}" "f452adb7c255f6d9d6d2573c6add7cb28022b151"
 namespace TestOutput
 {
 #line 1 "Imports.cshtml"
@@ -16,6 +16,24 @@ using Foo = System.Text.Encoding
 #line 3 "Imports.cshtml"
 using System
 
+#line default
+#line hidden
+    ;
+#line 5 "Imports.cshtml"
+using static System
+
+#line default
+#line hidden
+    ;
+#line 6 "Imports.cshtml"
+using static System.Console
+
+#line default
+#line hidden
+    ;
+#line 7 "Imports.cshtml"
+using static global::System.Text.Encoding
+
 #line default
 #line hidden
     ;
@@ -31,27 +49,30 @@ using System
         #pragma warning disable 1998
         public override async Task ExecuteAsync()
         {
-            Instrumentation.BeginContext(68, 30, true);
+            Instrumentation.BeginContext(68, 2, true);
+            WriteLiteral("\r\n");
+            Instrumentation.EndContext();
+            Instrumentation.BeginContext(166, 30, true);
             WriteLiteral("\r\n<p>Path\'s full type name is ");
             Instrumentation.EndContext();
-            Instrumentation.BeginContext(99, 21, false);
+            Instrumentation.BeginContext(197, 21, false);
-#line 5 "Imports.cshtml"
+#line 9 "Imports.cshtml"
                        Write(typeof(Path).FullName);
 
 #line default
 #line hidden
             Instrumentation.EndContext();
-            Instrumentation.BeginContext(120, 40, true);
+            Instrumentation.BeginContext(218, 40, true);
             WriteLiteral("</p>\r\n<p>Foo\'s actual full type name is ");
             Instrumentation.EndContext();
-            Instrumentation.BeginContext(161, 20, false);
+            Instrumentation.BeginContext(259, 20, false);
-#line 6 "Imports.cshtml"
+#line 10 "Imports.cshtml"
                              Write(typeof(Foo).FullName);
 
 #line default
 #line hidden
             Instrumentation.EndContext();
-            Instrumentation.BeginContext(181, 4, true);
+            Instrumentation.BeginContext(279, 4, true);
             WriteLiteral("</p>");
             Instrumentation.EndContext();
         }

test/Microsoft.AspNet.Razor.Test/TestFiles/CodeGenerator/CS/Source/Imports.cshtml

@@ -2,5 +2,9 @@
 @using Foo = System.Text.Encoding
 @using System
 
+@using static System
+@using static System.Console
+@using static global::System.Text.Encoding
+
 <p>Path's full type name is @typeof(Path).FullName</p>
 <p>Foo's actual full type name is @typeof(Foo).FullName</p>