Convert CSharpSpecialBlockTest to use baselines.

#2263

test/Microsoft.AspNetCore.Razor.Language.Test/Legacy/CSharpSpecialBlockTest.cs

@@ -2,245 +2,64 @@
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System;
-using Microsoft.AspNetCore.Razor.Language.Extensions;
 using Xunit;
 
 namespace Microsoft.AspNetCore.Razor.Language.Legacy
 {
     public class CSharpSpecialBlockTest : CsHtmlCodeParserTestBase
     {
-        [Fact]
-        public void ParseInheritsStatementMarksInheritsSpanAsCanGrowIfMissingTrailingSpace()
+        public CSharpSpecialBlockTest()
         {
-            // Arrange
-            var chunkGenerator = new DirectiveChunkGenerator(InheritsDirective.Directive);
-            chunkGenerator.Diagnostics.Add(
-                RazorDiagnosticFactory.CreateParsing_UnexpectedEOFAfterDirective(
-                    new SourceSpan(new SourceLocation(9, 0, 9), 1), InheritsDirective.Directive.Directive, "type"));
-
-            // Act & Assert
-            ParseDocumentTest(
-                "@inherits",
-                new[] { InheritsDirective.Directive },
-                new MarkupBlock(
-                    Factory.EmptyHtml(),
-                    new DirectiveBlock(chunkGenerator,
-                        Factory.CodeTransition(),
-                        Factory.MetaCode("inherits").Accepts(AcceptedCharactersInternal.None),
-                        Factory.Span(SpanKindInternal.Code, string.Empty, CSharpSymbolType.Unknown)
-                            .AsDirectiveToken(DirectiveTokenDescriptor.CreateToken(DirectiveTokenKind.Type))),
-                    Factory.EmptyHtml()));
-        }
-
-        [Fact]
-        public void InheritsBlockAcceptsMultipleGenericArguments()
-        {
-            ParseDocumentTest(
-                "@inherits Foo.Bar<Biz<Qux>, string, int>.Baz",
-                new[] { InheritsDirective.Directive },
-                new MarkupBlock(
-                    Factory.EmptyHtml(),
-                    new DirectiveBlock(new DirectiveChunkGenerator(InheritsDirective.Directive),
-                        Factory.CodeTransition(),
-                        Factory.MetaCode("inherits").Accepts(AcceptedCharactersInternal.None),
-                        Factory.Span(SpanKindInternal.Code, " ", CSharpSymbolType.WhiteSpace).Accepts(AcceptedCharactersInternal.WhiteSpace),
-                        Factory.Span(SpanKindInternal.Code, "Foo.Bar<Biz<Qux>, string, int>.Baz", markup: false).AsDirectiveToken(InheritsDirective.Directive.Tokens[0])),
-                    Factory.EmptyHtml()));
-        }
-
-        [Fact]
-        public void InheritsBlockOutputsErrorIfInheritsNotFollowedByTypeButAcceptsEntireLineAsCode()
-        {
-            // Arrange
-            var chunkGenerator = new DirectiveChunkGenerator(InheritsDirective.Directive);
-            chunkGenerator.Diagnostics.Add(
-                RazorDiagnosticFactory.CreateParsing_DirectiveExpectsTypeName(
-                    new SourceSpan(new SourceLocation(25, 0, 25), Environment.NewLine.Length),
-                    InheritsDirective.Directive.Directive));
-
-            // Act & Assert
-            ParseDocumentTest(
-                "@inherits                " + Environment.NewLine + "foo",
-                new[] { InheritsDirective.Directive },
-                new MarkupBlock(
-                    Factory.EmptyHtml(),
-                    new DirectiveBlock(chunkGenerator,
-                        Factory.CodeTransition(),
-                        Factory.MetaCode("inherits").Accepts(AcceptedCharactersInternal.None),
-                        Factory.Span(SpanKindInternal.Code, "                ", CSharpSymbolType.WhiteSpace).Accepts(AcceptedCharactersInternal.WhiteSpace),
-                        Factory.Span(SpanKindInternal.Code, string.Empty, CSharpSymbolType.Unknown)
-                            .AsDirectiveToken(DirectiveTokenDescriptor.CreateToken(DirectiveTokenKind.Type))),
-                    Factory.Markup(Environment.NewLine + "foo")));
+            UseBaselineTests = true;
         }
 
         [Fact]
         public void NamespaceImportInsideCodeBlockCausesError()
         {
-            ParseBlockTest("{ using Foo.Bar.Baz; var foo = bar; }",
-                           new StatementBlock(
-                               Factory.MetaCode("{").Accepts(AcceptedCharactersInternal.None),
-                               Factory.Code(" using Foo.Bar.Baz; var foo = bar; ")
-                                   .AsStatement()
-                                   .AutoCompleteWith(autoCompleteString: null),
-                               Factory.MetaCode("}").Accepts(AcceptedCharactersInternal.None)
-                               ),
-                           RazorDiagnosticFactory.CreateParsing_NamespaceImportAndTypeAliasCannotExistWithinCodeBlock(
-                               new SourceSpan(new SourceLocation(2, 0, 2), contentLength: 5)));
+            ParseBlockTest("{ using Foo.Bar.Baz; var foo = bar; }");
         }
 
         [Fact]
         public void TypeAliasInsideCodeBlockIsNotHandledSpecially()
         {
-            ParseBlockTest("{ using Foo = Bar.Baz; var foo = bar; }",
-                           new StatementBlock(
-                               Factory.MetaCode("{").Accepts(AcceptedCharactersInternal.None),
-                               Factory.Code(" using Foo = Bar.Baz; var foo = bar; ")
-                                   .AsStatement()
-                                   .AutoCompleteWith(autoCompleteString: null),
-                               Factory.MetaCode("}").Accepts(AcceptedCharactersInternal.None)
-                               ),
-                           RazorDiagnosticFactory.CreateParsing_NamespaceImportAndTypeAliasCannotExistWithinCodeBlock(
-                               new SourceSpan(new SourceLocation(2, 0, 2), contentLength: 5)));
-        }
-
-        [Fact]
-        public void Plan9FunctionsKeywordInsideCodeBlockIsNotHandledSpecially()
-        {
-            ParseBlockTest("{ functions Foo; }",
-                           new StatementBlock(
-                               Factory.MetaCode("{").Accepts(AcceptedCharactersInternal.None),
-                               Factory.Code(" functions Foo; ")
-                                   .AsStatement()
-                                   .AutoCompleteWith(autoCompleteString: null),
-                               Factory.MetaCode("}").Accepts(AcceptedCharactersInternal.None)
-                               ));
+            ParseBlockTest("{ using Foo = Bar.Baz; var foo = bar; }");
         }
 
         [Fact]
         public void NonKeywordStatementInCodeBlockIsHandledCorrectly()
         {
-            ParseBlockTest("{" + Environment.NewLine
-                         + "    List<dynamic> photos = gallery.Photo.ToList();" + Environment.NewLine
-                         + "}",
-                           new StatementBlock(
-                               Factory.MetaCode("{").Accepts(AcceptedCharactersInternal.None),
-                               Factory.Code($"{Environment.NewLine}    List<dynamic> photos = gallery.Photo.ToList();{Environment.NewLine}")
-                                   .AsStatement()
-                                   .AutoCompleteWith(autoCompleteString: null),
-                               Factory.MetaCode("}").Accepts(AcceptedCharactersInternal.None)
-                               ));
+            ParseBlockTest(
+@"{
+    List<dynamic> photos = gallery.Photo.ToList();
+}");
         }
 
         [Fact]
         public void ParseBlockBalancesBracesOutsideStringsIfFirstCharacterIsBraceAndReturnsSpanOfTypeCode()
         {
-            // Arrange
-            const string code = "foo\"b}ar\" if(condition) { string.Format(\"{0}\"); } ";
-
-            // Act/Assert
-            ParseBlockTest("{" + code + "}",
-                           new StatementBlock(
-                               Factory.MetaCode("{").Accepts(AcceptedCharactersInternal.None),
-                               Factory.Code(code)
-                                   .AsStatement()
-                                   .AutoCompleteWith(autoCompleteString: null),
-                               Factory.MetaCode("}").Accepts(AcceptedCharactersInternal.None)
-                               ));
+            ParseBlockTest("{foo\"b}ar\" if(condition) { string.Format(\"{0}\"); } }");
         }
 
         [Fact]
         public void ParseBlockBalancesParensOutsideStringsIfFirstCharacterIsParenAndReturnsSpanOfTypeExpression()
         {
-            // Arrange
-            const string code = "foo\"b)ar\" if(condition) { string.Format(\"{0}\"); } ";
-
-            // Act/Assert
-            ParseBlockTest("(" + code + ")",
-                           new ExpressionBlock(
-                               Factory.MetaCode("(").Accepts(AcceptedCharactersInternal.None),
-                               Factory.Code(code).AsExpression(),
-                               Factory.MetaCode(")").Accepts(AcceptedCharactersInternal.None)
-                               ));
-        }
-
-        [Fact]
-        public void ParseBlockBalancesBracesAndOutputsContentAsClassLevelCodeSpanIfFirstIdentifierIsFunctionsKeyword()
-        {
-            const string code = " foo(); \"bar}baz\" ";
-            ParseBlockTest(
-                "functions {" + code + "} zoop",
-                new[] { FunctionsDirective.Directive },
-                new DirectiveBlock(new DirectiveChunkGenerator(FunctionsDirective.Directive),
-                    Factory.MetaCode("functions").Accepts(AcceptedCharactersInternal.None),
-                    Factory.Span(SpanKindInternal.Markup, " ", CSharpSymbolType.WhiteSpace).Accepts(AcceptedCharactersInternal.AllWhiteSpace),
-                    Factory.MetaCode("{").AutoCompleteWith(null, atEndOfSpan: true).Accepts(AcceptedCharactersInternal.None),
-                    Factory.Code(code).AsCodeBlock(),
-                    Factory.MetaCode("}").Accepts(AcceptedCharactersInternal.None)));
-        }
-
-        [Fact]
-        public void ParseBlockDoesNoErrorRecoveryForFunctionsBlock()
-        {
-            // Arrange
-            var chunkGenerator = new DirectiveChunkGenerator(FunctionsDirective.Directive);
-            chunkGenerator.Diagnostics.Add(
-                RazorDiagnosticFactory.CreateParsing_ExpectedEndOfBlockBeforeEOF(
-                    new SourceSpan(new SourceLocation(10, 0, 10), contentLength: 1), "functions", "}", "{"));
-
-            // Act & Assert
-            ParseBlockTest(
-                "functions { { { { { } zoop",
-                new[] { FunctionsDirective.Directive },
-                new DirectiveBlock(chunkGenerator,
-                    Factory.MetaCode("functions").Accepts(AcceptedCharactersInternal.None),
-                    Factory.Span(SpanKindInternal.Markup, " ", CSharpSymbolType.WhiteSpace).Accepts(AcceptedCharactersInternal.AllWhiteSpace),
-                    Factory.MetaCode("{").AutoCompleteWith("}", atEndOfSpan: true).Accepts(AcceptedCharactersInternal.None),
-                    Factory.Code(" { { { { } zoop").AsCodeBlock()));
-        }
-
-        [Fact]
-        public void ParseBlockIgnoresFunctionsUnlessAllLowerCase()
-        {
-            ParseBlockTest("Functions { foo() }",
-                           new ExpressionBlock(
-                               Factory.Code("Functions")
-                                   .AsImplicitExpression(CSharpCodeParser.DefaultKeywords)
-                                   .Accepts(AcceptedCharactersInternal.NonWhiteSpace)));
+            ParseBlockTest("(foo\"b)ar\" if(condition) { string.Format(\"{0}\"); } )");
         }
 
         [Fact]
         public void ParseBlockIgnoresSingleSlashAtStart()
         {
-            ParseBlockTest("@/ foo",
-                           new ExpressionBlock(
-                               Factory.CodeTransition(),
-                               Factory.EmptyCSharp()
-                                   .AsImplicitExpression(CSharpCodeParser.DefaultKeywords)
-                                   .Accepts(AcceptedCharactersInternal.NonWhiteSpace)),
-                           RazorDiagnosticFactory.CreateParsing_UnexpectedCharacterAtStartOfCodeBlock(
-                                new SourceSpan(new SourceLocation(1, 0, 1), contentLength: 1),
-                                "/"));
+            ParseBlockTest("@/ foo");
         }
 
         [Fact]
         public void ParseBlockTerminatesSingleLineCommentAtEndOfLine()
         {
-            ParseBlockTest("if(!false) {" + Environment.NewLine
-                         + "    // Foo" + Environment.NewLine
-                         + "\t<p>A real tag!</p>" + Environment.NewLine
-                         + "}",
-                           new StatementBlock(
-                               Factory.Code($"if(!false) {{{Environment.NewLine}    // Foo{Environment.NewLine}").AsStatement(),
-                               new MarkupBlock(
-                                   Factory.Markup("\t"),
-                                   new MarkupTagBlock(
-                                       Factory.Markup("<p>").Accepts(AcceptedCharactersInternal.None)),
-                                   Factory.Markup("A real tag!"),
-                                   new MarkupTagBlock(
-                                       Factory.Markup("</p>").Accepts(AcceptedCharactersInternal.None)),
-                                   Factory.Markup(Environment.NewLine).Accepts(AcceptedCharactersInternal.None)),
-                               Factory.Code("}").AsStatement()
-                               ));
+            ParseBlockTest(
+"if(!false) {" + Environment.NewLine +
+"    // Foo" + Environment.NewLine +
+"\t<p>A real tag!</p>" + Environment.NewLine +
+"}");
         }
     }
 }

test/Microsoft.AspNetCore.Razor.Language.Test/TestFiles/ParserTests/CSharpSpecialBlockTest/NamespaceImportInsideCodeBlockCausesError.diagnostics.txt

@@ -0,0 +1,6 @@
+(1,3): Error RZ2004: Namespace imports and type aliases cannot be placed within code blocks.  They must immediately follow an "@" character in markup.  It is recommended that you put them at the top of the page, as in the following example:
+
+@using System.Drawing;
+@{
+    // OK here to use types from System.Drawing in the page.
+}

test/Microsoft.AspNetCore.Razor.Language.Test/TestFiles/ParserTests/CSharpSpecialBlockTest/NamespaceImportInsideCodeBlockCausesError.syntaxtree.txt

@@ -0,0 +1,25 @@
+Statement block - Gen<None> - 37 - (0:0,0)
+    MetaCode span - Gen<None> - [{] - SpanEditHandler;Accepts:None - (0:0,0) - Symbols:1
+        CSharpSymbolType.LeftBrace;[{];
+    Code span - Gen<Stmt> - [ using Foo.Bar.Baz; var foo = bar; ] - AutoCompleteEditHandler;Accepts:Any,AutoComplete:[<null>];AtEOL - (1:0,1) - Symbols:19
+        CSharpSymbolType.WhiteSpace;[ ];
+        CSharpSymbolType.Keyword;[using];
+        CSharpSymbolType.WhiteSpace;[ ];
+        CSharpSymbolType.Identifier;[Foo];
+        CSharpSymbolType.Dot;[.];
+        CSharpSymbolType.Identifier;[Bar];
+        CSharpSymbolType.Dot;[.];
+        CSharpSymbolType.Identifier;[Baz];
+        CSharpSymbolType.Semicolon;[;];
+        CSharpSymbolType.WhiteSpace;[ ];
+        CSharpSymbolType.Identifier;[var];
+        CSharpSymbolType.WhiteSpace;[ ];
+        CSharpSymbolType.Identifier;[foo];
+        CSharpSymbolType.WhiteSpace;[ ];
+        CSharpSymbolType.Assign;[=];
+        CSharpSymbolType.WhiteSpace;[ ];
+        CSharpSymbolType.Identifier;[bar];
+        CSharpSymbolType.Semicolon;[;];
+        CSharpSymbolType.WhiteSpace;[ ];
+    MetaCode span - Gen<None> - [}] - SpanEditHandler;Accepts:None - (36:0,36) - Symbols:1
+        CSharpSymbolType.RightBrace;[}];

test/Microsoft.AspNetCore.Razor.Language.Test/TestFiles/ParserTests/CSharpSpecialBlockTest/NonKeywordStatementInCodeBlockIsHandledCorrectly.syntaxtree.txt

@@ -0,0 +1,26 @@
+Statement block - Gen<None> - 56 - (0:0,0)
+    MetaCode span - Gen<None> - [{] - SpanEditHandler;Accepts:None - (0:0,0) - Symbols:1
+        CSharpSymbolType.LeftBrace;[{];
+    Code span - Gen<Stmt> - [LF    List<dynamic> photos = gallery.Photo.ToList();LF] - AutoCompleteEditHandler;Accepts:Any,AutoComplete:[<null>];AtEOL - (1:0,1) - Symbols:20
+        CSharpSymbolType.NewLine;[LF];
+        CSharpSymbolType.WhiteSpace;[    ];
+        CSharpSymbolType.Identifier;[List];
+        CSharpSymbolType.LessThan;[<];
+        CSharpSymbolType.Identifier;[dynamic];
+        CSharpSymbolType.GreaterThan;[>];
+        CSharpSymbolType.WhiteSpace;[ ];
+        CSharpSymbolType.Identifier;[photos];
+        CSharpSymbolType.WhiteSpace;[ ];
+        CSharpSymbolType.Assign;[=];
+        CSharpSymbolType.WhiteSpace;[ ];
+        CSharpSymbolType.Identifier;[gallery];
+        CSharpSymbolType.Dot;[.];
+        CSharpSymbolType.Identifier;[Photo];
+        CSharpSymbolType.Dot;[.];
+        CSharpSymbolType.Identifier;[ToList];
+        CSharpSymbolType.LeftParenthesis;[(];
+        CSharpSymbolType.RightParenthesis;[)];
+        CSharpSymbolType.Semicolon;[;];
+        CSharpSymbolType.NewLine;[LF];
+    MetaCode span - Gen<None> - [}] - SpanEditHandler;Accepts:None - (55:2,0) - Symbols:1
+        CSharpSymbolType.RightBrace;[}];

test/Microsoft.AspNetCore.Razor.Language.Test/TestFiles/ParserTests/CSharpSpecialBlockTest/ParseBlockBalancesBracesOutsideStringsIfFirstCharacterIsBraceAndReturnsSpanOfTypeCode.syntaxtree.txt

@@ -0,0 +1,26 @@
+Statement block - Gen<None> - 52 - (0:0,0)
+    MetaCode span - Gen<None> - [{] - SpanEditHandler;Accepts:None - (0:0,0) - Symbols:1
+        CSharpSymbolType.LeftBrace;[{];
+    Code span - Gen<Stmt> - [foo"b}ar" if(condition) { string.Format("{0}"); } ] - AutoCompleteEditHandler;Accepts:Any,AutoComplete:[<null>];AtEOL - (1:0,1) - Symbols:20
+        CSharpSymbolType.Identifier;[foo];
+        CSharpSymbolType.StringLiteral;["b}ar"];
+        CSharpSymbolType.WhiteSpace;[ ];
+        CSharpSymbolType.Keyword;[if];
+        CSharpSymbolType.LeftParenthesis;[(];
+        CSharpSymbolType.Identifier;[condition];
+        CSharpSymbolType.RightParenthesis;[)];
+        CSharpSymbolType.WhiteSpace;[ ];
+        CSharpSymbolType.LeftBrace;[{];
+        CSharpSymbolType.WhiteSpace;[ ];
+        CSharpSymbolType.Keyword;[string];
+        CSharpSymbolType.Dot;[.];
+        CSharpSymbolType.Identifier;[Format];
+        CSharpSymbolType.LeftParenthesis;[(];
+        CSharpSymbolType.StringLiteral;["{0}"];
+        CSharpSymbolType.RightParenthesis;[)];
+        CSharpSymbolType.Semicolon;[;];
+        CSharpSymbolType.WhiteSpace;[ ];
+        CSharpSymbolType.RightBrace;[}];
+        CSharpSymbolType.WhiteSpace;[ ];
+    MetaCode span - Gen<None> - [}] - SpanEditHandler;Accepts:None - (51:0,51) - Symbols:1
+        CSharpSymbolType.RightBrace;[}];

test/Microsoft.AspNetCore.Razor.Language.Test/TestFiles/ParserTests/CSharpSpecialBlockTest/ParseBlockBalancesParensOutsideStringsIfFirstCharacterIsParenAndReturnsSpanOfTypeExpression.syntaxtree.txt

@@ -0,0 +1,26 @@
+Expression block - Gen<Expr> - 52 - (0:0,0)
+    MetaCode span - Gen<None> - [(] - SpanEditHandler;Accepts:None - (0:0,0) - Symbols:1
+        CSharpSymbolType.LeftParenthesis;[(];
+    Code span - Gen<Expr> - [foo"b)ar" if(condition) { string.Format("{0}"); } ] - SpanEditHandler;Accepts:Any - (1:0,1) - Symbols:20
+        CSharpSymbolType.Identifier;[foo];
+        CSharpSymbolType.StringLiteral;["b)ar"];
+        CSharpSymbolType.WhiteSpace;[ ];
+        CSharpSymbolType.Keyword;[if];
+        CSharpSymbolType.LeftParenthesis;[(];
+        CSharpSymbolType.Identifier;[condition];
+        CSharpSymbolType.RightParenthesis;[)];
+        CSharpSymbolType.WhiteSpace;[ ];
+        CSharpSymbolType.LeftBrace;[{];
+        CSharpSymbolType.WhiteSpace;[ ];
+        CSharpSymbolType.Keyword;[string];
+        CSharpSymbolType.Dot;[.];
+        CSharpSymbolType.Identifier;[Format];
+        CSharpSymbolType.LeftParenthesis;[(];
+        CSharpSymbolType.StringLiteral;["{0}"];
+        CSharpSymbolType.RightParenthesis;[)];
+        CSharpSymbolType.Semicolon;[;];
+        CSharpSymbolType.WhiteSpace;[ ];
+        CSharpSymbolType.RightBrace;[}];
+        CSharpSymbolType.WhiteSpace;[ ];
+    MetaCode span - Gen<None> - [)] - SpanEditHandler;Accepts:None - (51:0,51) - Symbols:1
+        CSharpSymbolType.RightParenthesis;[)];

test/Microsoft.AspNetCore.Razor.Language.Test/TestFiles/ParserTests/CSharpSpecialBlockTest/ParseBlockIgnoresSingleSlashAtStart.diagnostics.txt

@@ -0,0 +1 @@
+(1,2): Error RZ1005: "/" is not valid at the start of a code block.  Only identifiers, keywords, comments, "(" and "{" are valid.

test/Microsoft.AspNetCore.Razor.Language.Test/TestFiles/ParserTests/CSharpSpecialBlockTest/ParseBlockIgnoresSingleSlashAtStart.syntaxtree.txt

@@ -0,0 +1,5 @@
+Expression block - Gen<Expr> - 1 - (0:0,0)
+    Transition span - Gen<None> - [@] - SpanEditHandler;Accepts:None - (0:0,0) - Symbols:1
+        CSharpSymbolType.Transition;[@];
+    Code span - Gen<Expr> - [] - ImplicitExpressionEditHandler;Accepts:NonWhiteSpace;ImplicitExpression[RTD];K14 - (1:0,1) - Symbols:1
+        CSharpSymbolType.Unknown;[];

test/Microsoft.AspNetCore.Razor.Language.Test/TestFiles/ParserTests/CSharpSpecialBlockTest/ParseBlockTerminatesSingleLineCommentAtEndOfLine.syntaxtree.txt

@@ -0,0 +1,38 @@
+Statement block - Gen<None> - 48 - (0:0,0)
+    Code span - Gen<Stmt> - [if(!false) {LF    // FooLF] - SpanEditHandler;Accepts:Any - (0:0,0) - Symbols:11
+        CSharpSymbolType.Keyword;[if];
+        CSharpSymbolType.LeftParenthesis;[(];
+        CSharpSymbolType.Not;[!];
+        CSharpSymbolType.Keyword;[false];
+        CSharpSymbolType.RightParenthesis;[)];
+        CSharpSymbolType.WhiteSpace;[ ];
+        CSharpSymbolType.LeftBrace;[{];
+        CSharpSymbolType.NewLine;[LF];
+        CSharpSymbolType.WhiteSpace;[    ];
+        CSharpSymbolType.Comment;[// Foo];
+        CSharpSymbolType.NewLine;[LF];
+    Markup block - Gen<None> - 21 - (26:2,0)
+        Markup span - Gen<Markup> - [	] - SpanEditHandler;Accepts:Any - (26:2,0) - Symbols:1
+            HtmlSymbolType.WhiteSpace;[	];
+        Tag block - Gen<None> - 3 - (27:2,1)
+            Markup span - Gen<Markup> - [<p>] - SpanEditHandler;Accepts:None - (27:2,1) - Symbols:3
+                HtmlSymbolType.OpenAngle;[<];
+                HtmlSymbolType.Text;[p];
+                HtmlSymbolType.CloseAngle;[>];
+        Markup span - Gen<Markup> - [A real tag!] - SpanEditHandler;Accepts:Any - (30:2,4) - Symbols:6
+            HtmlSymbolType.Text;[A];
+            HtmlSymbolType.WhiteSpace;[ ];
+            HtmlSymbolType.Text;[real];
+            HtmlSymbolType.WhiteSpace;[ ];
+            HtmlSymbolType.Text;[tag];
+            HtmlSymbolType.Bang;[!];
+        Tag block - Gen<None> - 4 - (41:2,15)
+            Markup span - Gen<Markup> - [</p>] - SpanEditHandler;Accepts:None - (41:2,15) - Symbols:4
+                HtmlSymbolType.OpenAngle;[<];
+                HtmlSymbolType.ForwardSlash;[/];
+                HtmlSymbolType.Text;[p];
+                HtmlSymbolType.CloseAngle;[>];
+        Markup span - Gen<Markup> - [LF] - SpanEditHandler;Accepts:None - (45:2,19) - Symbols:1
+            HtmlSymbolType.NewLine;[LF];
+    Code span - Gen<Stmt> - [}] - SpanEditHandler;Accepts:Any - (47:3,0) - Symbols:1
+        CSharpSymbolType.RightBrace;[}];

test/Microsoft.AspNetCore.Razor.Language.Test/TestFiles/ParserTests/CSharpSpecialBlockTest/TypeAliasInsideCodeBlockIsNotHandledSpecially.diagnostics.txt

@@ -0,0 +1,6 @@
+(1,3): Error RZ2004: Namespace imports and type aliases cannot be placed within code blocks.  They must immediately follow an "@" character in markup.  It is recommended that you put them at the top of the page, as in the following example:
+
+@using System.Drawing;
+@{
+    // OK here to use types from System.Drawing in the page.
+}

test/Microsoft.AspNetCore.Razor.Language.Test/TestFiles/ParserTests/CSharpSpecialBlockTest/TypeAliasInsideCodeBlockIsNotHandledSpecially.syntaxtree.txt

@@ -0,0 +1,27 @@
+Statement block - Gen<None> - 39 - (0:0,0)
+    MetaCode span - Gen<None> - [{] - SpanEditHandler;Accepts:None - (0:0,0) - Symbols:1
+        CSharpSymbolType.LeftBrace;[{];
+    Code span - Gen<Stmt> - [ using Foo = Bar.Baz; var foo = bar; ] - AutoCompleteEditHandler;Accepts:Any,AutoComplete:[<null>];AtEOL - (1:0,1) - Symbols:21
+        CSharpSymbolType.WhiteSpace;[ ];
+        CSharpSymbolType.Keyword;[using];
+        CSharpSymbolType.WhiteSpace;[ ];
+        CSharpSymbolType.Identifier;[Foo];
+        CSharpSymbolType.WhiteSpace;[ ];
+        CSharpSymbolType.Assign;[=];
+        CSharpSymbolType.WhiteSpace;[ ];
+        CSharpSymbolType.Identifier;[Bar];
+        CSharpSymbolType.Dot;[.];
+        CSharpSymbolType.Identifier;[Baz];
+        CSharpSymbolType.Semicolon;[;];
+        CSharpSymbolType.WhiteSpace;[ ];
+        CSharpSymbolType.Identifier;[var];
+        CSharpSymbolType.WhiteSpace;[ ];
+        CSharpSymbolType.Identifier;[foo];
+        CSharpSymbolType.WhiteSpace;[ ];
+        CSharpSymbolType.Assign;[=];
+        CSharpSymbolType.WhiteSpace;[ ];
+        CSharpSymbolType.Identifier;[bar];
+        CSharpSymbolType.Semicolon;[;];
+        CSharpSymbolType.WhiteSpace;[ ];
+    MetaCode span - Gen<None> - [}] - SpanEditHandler;Accepts:None - (38:0,38) - Symbols:1
+        CSharpSymbolType.RightBrace;[}];