src/Compilers/VisualBasic/Test/Syntax/Scanner/ScannerTests.vb - main - githubmirror/roslyn

src/Compilers/VisualBasic/Test/Syntax/Scanner/ScannerTests.vb
2 191 строка86 KB
Tomáš Matoušek
Refactoring of extension methods in source packages (#78620) - take 2 (#78894)
26 июн 2025, 18:42
26 июн 2025, 18:4205fc006
' Licensed to the .NET Foundation under one or more agreements.
' The .NET Foundation licenses this file to you under the MIT license.
' See the LICENSE file in the project root for more information.

Imports System.Runtime.CompilerServices
Imports System.Threading.Thread
Imports Microsoft.CodeAnalysis
Imports Microsoft.CodeAnalysis.Collections
Imports Microsoft.CodeAnalysis.Syntax.InternalSyntax
Imports Microsoft.CodeAnalysis.VisualBasic
Imports Microsoft.CodeAnalysis.VisualBasic.Syntax
Imports Roslyn.Test.Utilities

<CLSCompliant(False)>
Public Class ScannerTests
    Inherits BasicTestBase

    Private Function ScanOnce(str As String, Optional startStatement As Boolean = False) As SyntaxToken
        Return SyntaxFactory.ParseToken(str, startStatement:=startStatement)
    End Function

    Private Function ScanOnce(str As String, languageVersion As VisualBasic.LanguageVersion) As SyntaxToken
        Return SyntaxFactory.ParseTokens(str, options:=New VisualBasicParseOptions(languageVersion:=languageVersion)).First()
    End Function

    Private Function AsString(tokens As IEnumerable(Of SyntaxToken)) As String
        Dim str = String.Concat(From t In tokens Select t.ToFullString())
        Return str
    End Function

    Private Function MakeDwString(str As String) As String
        Return (From c In str Select If(c < ChrW(&H21S) OrElse c > ChrW(&H7ES), c, ChrW(AscW(c) + &HFF00US - &H20US))).ToArray
    End Function

    Private Function ScanAllCheckDw(str As String) As IEnumerable(Of SyntaxToken)
        Dim tokens = SyntaxFactory.ParseTokens(str)

        ' test that token have the same text as it was.
        Assert.Equal(str, AsString(tokens))

        ' test that we get same with doublewidth string
        Dim doubleWidthStr = MakeDwString(str)
        Dim doubleWidthTokens = ScanAllNoDwCheck(doubleWidthStr)

        Assert.Equal(tokens.Count, doubleWidthTokens.Count)

        For Each t In tokens.Zip(doubleWidthTokens, Function(t1, t2) Tuple.Create(t1, t2))
            Assert.Equal(t.Item1.Kind, t.Item2.Kind)
            Assert.Equal(t.Item1.Span, t.Item2.Span)
            Assert.Equal(t.Item1.FullSpan, t.Item2.FullSpan)
            Assert.Equal(MakeDwString(t.Item1.ToFullString()), t.Item2.ToFullString())
        Next

        Return tokens
    End Function

    Private Function ScanAllNoDwCheck(str As String) As IEnumerable(Of SyntaxToken)
        Dim tokens = SyntaxFactory.ParseTokens(str)

        ' test that token have the same text as it was.
        Assert.Equal(str, AsString(tokens))

        Return tokens
    End Function

    <Fact>
    Public Sub TestLessThanConflictMarker1()
        ' Needs to be followed by a space.
        Dim token = SyntaxFactory.ParseTokens("<<<<<<<").First()
        Assert.Equal(SyntaxKind.LessThanLessThanToken, token.Kind())

        ' Has to be the start of a line.
        token = SyntaxFactory.ParseTokens(" <<<<<<<").First()
        Assert.Equal(SyntaxKind.LessThanLessThanToken, token.Kind())
        Assert.True(token.HasLeadingTrivia)
        Assert.True(token.LeadingTrivia.Single().Kind() = SyntaxKind.WhitespaceTrivia)

        ' Has to have at least seven characters.
        token = SyntaxFactory.ParseTokens("<<<<<< ").First()
        Assert.Equal(SyntaxKind.LessThanLessThanToken, token.Kind())

        ' Start of line, seven characters, ends with space.
        token = SyntaxFactory.ParseTokens("<<<<<<< ").First()
        Assert.Equal(SyntaxKind.EndOfFileToken, token.Kind())
        Assert.True(token.HasLeadingTrivia)
        Dim trivia = token.LeadingTrivia.Single()
        Assert.True(trivia.Kind() = SyntaxKind.ConflictMarkerTrivia)

        Assert.True(trivia.ContainsDiagnostics)
        Dim err = trivia.Errors().First
        Assert.Equal(ERRID.ERR_Merge_conflict_marker_encountered, err.Code)
    End Sub

    <Fact>
    Public Sub TestLessThanConflictMarker2()
        Dim token = SyntaxFactory.ParseTokens("{" & vbCrLf & "<<<<<<<").Skip(2).First()
        Assert.Equal(SyntaxKind.LessThanLessThanToken, token.Kind())

        token = SyntaxFactory.ParseTokens("{" & vbCrLf & " <<<<<<<").Skip(2).First()
        Assert.Equal(SyntaxKind.LessThanLessThanToken, token.Kind())
        Assert.True(token.HasLeadingTrivia)
        Assert.True(token.LeadingTrivia.Single().Kind() = SyntaxKind.WhitespaceTrivia)

        token = SyntaxFactory.ParseTokens("{" & vbCrLf & "<<<<<< ").Skip(2).First()
        Assert.Equal(SyntaxKind.LessThanLessThanToken, token.Kind())

        token = SyntaxFactory.ParseTokens("{" & vbCrLf & "<<<<<<< ").Skip(2).First()
        Assert.Equal(SyntaxKind.EndOfFileToken, token.Kind())
        Assert.True(token.HasLeadingTrivia)
        Dim trivia = token.LeadingTrivia.Single()
        Assert.True(trivia.Kind() = SyntaxKind.ConflictMarkerTrivia)
        Assert.True(trivia.SpanStart = 3)
        Assert.True(trivia.Span.Length = 8)

        Assert.True(trivia.ContainsDiagnostics)
        Dim err = trivia.Errors().First
        Assert.Equal(ERRID.ERR_Merge_conflict_marker_encountered, err.Code)
    End Sub

    <Fact>
    Public Sub TestGreaterThanConflictMarker1()
        ' Needs to be followed by a space.
        Dim token = SyntaxFactory.ParseTokens(">>>>>>>").First()
        Assert.Equal(SyntaxKind.GreaterThanGreaterThanToken, token.Kind())

        ' Has to be the start of a line.
        token = SyntaxFactory.ParseTokens(" >>>>>>>").First()
        Assert.Equal(SyntaxKind.GreaterThanGreaterThanToken, token.Kind())
        Assert.True(token.HasLeadingTrivia)
        Assert.True(token.LeadingTrivia.Single().Kind() = SyntaxKind.WhitespaceTrivia)

        ' Has to have at least seven characters.
        token = SyntaxFactory.ParseTokens(">>>>>> ").First()
        Assert.Equal(SyntaxKind.GreaterThanGreaterThanToken, token.Kind())

        ' Start of line, seven characters, ends with space.
        token = SyntaxFactory.ParseTokens(">>>>>>> ").First()
        Assert.Equal(SyntaxKind.EndOfFileToken, token.Kind())
        Assert.True(token.HasLeadingTrivia)
        Dim trivia = token.LeadingTrivia.Single()
        Assert.True(trivia.Kind() = SyntaxKind.ConflictMarkerTrivia)

        Assert.True(trivia.ContainsDiagnostics)
        Dim err = trivia.Errors().First
        Assert.Equal(ERRID.ERR_Merge_conflict_marker_encountered, err.Code)
    End Sub

    <Fact>
    Public Sub TestGreaterThanConflictMarker2()
        Dim token = SyntaxFactory.ParseTokens("{" & vbCrLf & ">>>>>>>").Skip(2).First()
        Assert.Equal(SyntaxKind.GreaterThanGreaterThanToken, token.Kind())

        token = SyntaxFactory.ParseTokens("{" & vbCrLf & " >>>>>>>").Skip(2).First()
        Assert.Equal(SyntaxKind.GreaterThanGreaterThanToken, token.Kind())
        Assert.True(token.HasLeadingTrivia)
        Assert.True(token.LeadingTrivia.Single().Kind() = SyntaxKind.WhitespaceTrivia)

        token = SyntaxFactory.ParseTokens("{" & vbCrLf & ">>>>>> ").Skip(2).First()
        Assert.Equal(SyntaxKind.GreaterThanGreaterThanToken, token.Kind())

        token = SyntaxFactory.ParseTokens("{" & vbCrLf & ">>>>>>> ").Skip(2).First()
        Assert.Equal(SyntaxKind.EndOfFileToken, token.Kind())
        Assert.True(token.HasLeadingTrivia)
        Dim trivia = token.LeadingTrivia.Single()
        Assert.True(trivia.Kind() = SyntaxKind.ConflictMarkerTrivia)
        Assert.True(trivia.SpanStart = 3)
        Assert.True(trivia.Span.Length = 8)

        Assert.True(trivia.ContainsDiagnostics)
        Dim err = trivia.Errors().First
        Assert.Equal(ERRID.ERR_Merge_conflict_marker_encountered, err.Code)
    End Sub

    <Fact>
    Public Sub TestEqualsConflictMarker1()
        ' Has to be the start of a line.
        Dim token = SyntaxFactory.ParseTokens(" =======").First()
        Assert.Equal(SyntaxKind.EqualsToken, token.Kind())
        Assert.True(token.HasLeadingTrivia)
        Assert.True(token.LeadingTrivia.Single().Kind() = SyntaxKind.WhitespaceTrivia)

        ' Has to have at least seven characters.
        token = SyntaxFactory.ParseTokens("====== ").First()
        Assert.Equal(SyntaxKind.EqualsToken, token.Kind())

        ' Start of line, seven characters
        token = SyntaxFactory.ParseTokens("=======").First()
        Assert.Equal(SyntaxKind.EndOfFileToken, token.Kind())
        Assert.True(token.HasLeadingTrivia)
        Assert.True(token.LeadingTrivia.Single().Kind() = SyntaxKind.ConflictMarkerTrivia)

        ' Start of line, seven characters
        token = SyntaxFactory.ParseTokens("======= trailing chars").First()
        Assert.Equal(SyntaxKind.EndOfFileToken, token.Kind())
        Assert.True(token.HasLeadingTrivia)
        Dim trivia = token.LeadingTrivia.Single()
        Assert.True(trivia.Kind() = SyntaxKind.ConflictMarkerTrivia)
        Assert.Equal(trivia.Span.Length, 22)

        Assert.True(trivia.ContainsDiagnostics)
        Dim err = trivia.Errors().First
        Assert.Equal(ERRID.ERR_Merge_conflict_marker_encountered, err.Code)

        token = SyntaxFactory.ParseTokens("======= Trailing" & vbCrLf & "disabled text").First()
        Assert.Equal(SyntaxKind.EndOfFileToken, token.Kind())
        Assert.True(token.HasLeadingTrivia)
        Assert.Equal(3, token.LeadingTrivia.Count)
        trivia = token.LeadingTrivia(0)
        Assert.True(trivia.Kind() = SyntaxKind.ConflictMarkerTrivia)
        Assert.Equal(trivia.Span.Length, 16)

        Assert.True(trivia.ContainsDiagnostics)
        err = trivia.Errors().First
        Assert.Equal(ERRID.ERR_Merge_conflict_marker_encountered, err.Code)

        trivia = token.LeadingTrivia(1)
        Assert.True(trivia.Kind() = SyntaxKind.EndOfLineTrivia)
        Assert.Equal(trivia.Span.Start, 16)
        Assert.Equal(trivia.Span.Length, 2)

        trivia = token.LeadingTrivia(2)
        Assert.True(trivia.Kind() = SyntaxKind.DisabledTextTrivia)
        Assert.Equal(trivia.Span.Start, 18)
        Assert.Equal(trivia.Span.Length, 13)

        token = SyntaxFactory.ParseTokens("======= Trailing" & vbCrLf & "disabled text" & vbCrLf & ">>>> still disabled").First()
        Assert.Equal(SyntaxKind.EndOfFileToken, token.Kind())
        Assert.True(token.HasLeadingTrivia)
        Assert.Equal(3, token.LeadingTrivia.Count)

        trivia = token.LeadingTrivia(0)
        Assert.True(trivia.Kind() = SyntaxKind.ConflictMarkerTrivia)
        Assert.Equal(trivia.Span.Length, 16)

        Assert.True(trivia.ContainsDiagnostics)
        err = trivia.Errors().First
        Assert.Equal(ERRID.ERR_Merge_conflict_marker_encountered, err.Code)

        trivia = token.LeadingTrivia(1)
        Assert.True(trivia.Kind() = SyntaxKind.EndOfLineTrivia)
        Assert.Equal(trivia.Span.Length, 2)

        trivia = token.LeadingTrivia(2)
        Assert.True(trivia.Kind() = SyntaxKind.DisabledTextTrivia)
        Assert.Equal(trivia.Span.Length, 34)

        token = SyntaxFactory.ParseTokens("======= Trailing" & vbCrLf & "disabled text" & vbCrLf & ">>>>>>> Actually the end").First()
        Assert.Equal(SyntaxKind.EndOfFileToken, token.Kind())
        Assert.True(token.HasLeadingTrivia)
        Assert.Equal(token.LeadingTrivia.Count, 4)
        Dim trivia1 = token.LeadingTrivia(0)
        Assert.True(trivia1.Kind() = SyntaxKind.ConflictMarkerTrivia)
        Assert.Equal(trivia1.Span.Length, 16)

        Assert.True(trivia1.ContainsDiagnostics)
        err = trivia1.Errors().First
        Assert.Equal(ERRID.ERR_Merge_conflict_marker_encountered, err.Code)

        Dim trivia2 = token.LeadingTrivia(1)
        Assert.True(trivia2.Kind() = SyntaxKind.EndOfLineTrivia)
        Assert.Equal(trivia2.Span.Start, 16)
        Assert.Equal(trivia2.Span.Length, 2)

        Dim trivia3 = token.LeadingTrivia(2)
        Assert.True(trivia3.Kind() = SyntaxKind.DisabledTextTrivia)
        Assert.Equal(trivia3.Span.Start, 18)
        Assert.Equal(trivia3.Span.Length, 15)

        Dim trivia4 = token.LeadingTrivia(3)
        Assert.True(trivia4.Kind() = SyntaxKind.ConflictMarkerTrivia)
        Assert.Equal(trivia4.Span.Start, 33)
        Assert.Equal(trivia4.Span.Length, 24)

        Assert.True(trivia4.ContainsDiagnostics)
        err = trivia4.Errors().First
        Assert.Equal(ERRID.ERR_Merge_conflict_marker_encountered, err.Code)
    End Sub

    <Fact>
    Public Sub TestEqualsConflictMarker2()
        ' Has to be the start of a line.
        Dim token = SyntaxFactory.ParseTokens("{" & vbCrLf & " =======").Skip(2).First()
        Assert.Equal(SyntaxKind.EqualsToken, token.Kind())
        Assert.True(token.HasLeadingTrivia)
        Assert.True(token.LeadingTrivia.Single().Kind() = SyntaxKind.WhitespaceTrivia)

        ' Has to have at least seven characters.
        token = SyntaxFactory.ParseTokens("{" & vbCrLf & "====== ").Skip(2).First()
        Assert.Equal(SyntaxKind.EqualsToken, token.Kind())

        ' Start of line, seven characters
        token = SyntaxFactory.ParseTokens("{" & vbCrLf & "=======").Skip(2).First()
        Assert.Equal(SyntaxKind.EndOfFileToken, token.Kind())
        Assert.True(token.HasLeadingTrivia)
        Dim trivia = token.LeadingTrivia.Single()
        Assert.True(trivia.Kind() = SyntaxKind.ConflictMarkerTrivia)

        Assert.True(trivia.ContainsDiagnostics)
        Dim err = trivia.Errors().First
        Assert.Equal(ERRID.ERR_Merge_conflict_marker_encountered, err.Code)

        ' Start of line, seven characters
        token = SyntaxFactory.ParseTokens("{" & vbCrLf & "======= trailing chars").Skip(2).First()
        Assert.Equal(SyntaxKind.EndOfFileToken, token.Kind())
        Assert.True(token.HasLeadingTrivia)
        trivia = token.LeadingTrivia.Single()
        Assert.True(trivia.Kind() = SyntaxKind.ConflictMarkerTrivia)
        Assert.Equal(trivia.Span.Length, 22)

        Assert.True(trivia.ContainsDiagnostics)
        err = trivia.Errors().First
        Assert.Equal(ERRID.ERR_Merge_conflict_marker_encountered, err.Code)

        token = SyntaxFactory.ParseTokens("{" & vbCrLf & "======= Trailing" & vbCrLf & "disabled text").Skip(2).First()
        Assert.Equal(SyntaxKind.EndOfFileToken, token.Kind())
        Assert.True(token.HasLeadingTrivia)
        Assert.Equal(3, token.LeadingTrivia.Count)
        trivia = token.LeadingTrivia(0)
        Assert.True(trivia.Kind() = SyntaxKind.ConflictMarkerTrivia)
        Assert.Equal(trivia.Span.Length, 16)

        Assert.True(trivia.ContainsDiagnostics)
        err = trivia.Errors().First
        Assert.Equal(ERRID.ERR_Merge_conflict_marker_encountered, err.Code)

        trivia = token.LeadingTrivia(1)
        Assert.True(trivia.Kind() = SyntaxKind.EndOfLineTrivia)
        Assert.Equal(trivia.Span.Start, 19)
        Assert.Equal(trivia.Span.Length, 2)

        trivia = token.LeadingTrivia(2)
        Assert.True(trivia.Kind() = SyntaxKind.DisabledTextTrivia)
        Assert.Equal(trivia.Span.Start, 21)
        Assert.Equal(trivia.Span.Length, 13)

        token = SyntaxFactory.ParseTokens("{" & vbCrLf & "======= Trailing" & vbCrLf & "disabled text" & vbCrLf & ">>>> still disabled").Skip(2).First()
        Assert.Equal(SyntaxKind.EndOfFileToken, token.Kind())
        Assert.True(token.HasLeadingTrivia)
        Assert.Equal(3, token.LeadingTrivia.Count)

        trivia = token.LeadingTrivia(0)
        Assert.True(trivia.Kind() = SyntaxKind.ConflictMarkerTrivia)
        Assert.Equal(trivia.Span.Length, 16)

        Assert.True(trivia.ContainsDiagnostics)
        err = trivia.Errors().First
        Assert.Equal(ERRID.ERR_Merge_conflict_marker_encountered, err.Code)

        trivia = token.LeadingTrivia(1)
        Assert.True(trivia.Kind() = SyntaxKind.EndOfLineTrivia)
        Assert.Equal(trivia.Span.Length, 2)

        trivia = token.LeadingTrivia(2)
        Assert.True(trivia.Kind() = SyntaxKind.DisabledTextTrivia)
        Assert.Equal(trivia.Span.Length, 34)

        token = SyntaxFactory.ParseTokens("{" & vbCrLf & "======= Trailing" & vbCrLf & "disabled text" & vbCrLf & ">>>>>>> Actually the end").Skip(2).First()
        Assert.Equal(SyntaxKind.EndOfFileToken, token.Kind())
        Assert.True(token.HasLeadingTrivia)
        Assert.Equal(token.LeadingTrivia.Count, 4)
        Dim trivia1 = token.LeadingTrivia(0)
        Assert.True(trivia1.Kind() = SyntaxKind.ConflictMarkerTrivia)
        Assert.Equal(trivia1.Span.Length, 16)

        Assert.True(trivia1.ContainsDiagnostics)
        err = trivia1.Errors().First
        Assert.Equal(ERRID.ERR_Merge_conflict_marker_encountered, err.Code)

        Dim trivia2 = token.LeadingTrivia(1)
        Assert.True(trivia2.Kind() = SyntaxKind.EndOfLineTrivia)
        Assert.Equal(trivia2.Span.Start, 19)
        Assert.Equal(trivia2.Span.Length, 2)

        Dim trivia3 = token.LeadingTrivia(2)
        Assert.True(trivia3.Kind() = SyntaxKind.DisabledTextTrivia)
        Assert.Equal(trivia3.Span.Start, 21)
        Assert.Equal(trivia3.Span.Length, 15)

        Dim trivia4 = token.LeadingTrivia(3)
        Assert.True(trivia4.Kind() = SyntaxKind.ConflictMarkerTrivia)
        Assert.Equal(trivia4.Span.Start, 36)
        Assert.Equal(trivia4.Span.Length, 24)

        Assert.True(trivia4.ContainsDiagnostics)
        err = trivia4.Errors().First
        Assert.Equal(ERRID.ERR_Merge_conflict_marker_encountered, err.Code)
    End Sub

    <Fact>
    Public Sub TestEqualsConflictMarker3()
        Dim token = SyntaxFactory.ParseTokens("======= trailing chars" & vbCrLf & "======= more trailing chars").First()
        Assert.Equal(SyntaxKind.EndOfFileToken, token.Kind())
        Assert.True(token.HasLeadingTrivia)
        Assert.Equal(3, token.LeadingTrivia.Count)

        Dim trivia = token.LeadingTrivia(0)
        Assert.True(trivia.Kind() = SyntaxKind.ConflictMarkerTrivia)
        Assert.Equal(trivia.Span.Length, 22)
        Assert.Equal("======= trailing chars", trivia.ToFullString())
        Assert.True(trivia.ContainsDiagnostics)
        Assert.Equal(ERRID.ERR_Merge_conflict_marker_encountered, trivia.Errors().First().Code)

        trivia = token.LeadingTrivia(1)
        Assert.True(trivia.Kind() = SyntaxKind.EndOfLineTrivia)
        Assert.Equal(trivia.Span.Start, 22)
        Assert.Equal(trivia.Span.Length, 2)

        trivia = token.LeadingTrivia(2)
        Assert.True(trivia.Kind() = SyntaxKind.DisabledTextTrivia)
        Assert.Equal(trivia.Span.Start, 24)
        Assert.Equal(trivia.Span.Length, 27)
        Assert.Equal("======= more trailing chars", trivia.ToFullString())
    End Sub

    <Fact>
    Public Sub TestPipeConflictMarker1()
        ' Has to be the start of a line.
        Dim token = SyntaxFactory.ParseTokens(" |||||||").First()
        Assert.Equal(SyntaxKind.BadToken, token.Kind())
        Assert.True(token.HasLeadingTrivia)
        Assert.True(token.LeadingTrivia.Single().Kind() = SyntaxKind.WhitespaceTrivia)

        ' Has to have at least seven characters.
        token = SyntaxFactory.ParseTokens("|||||| ").First()
        Assert.Equal(SyntaxKind.BadToken, token.Kind())

        ' Start of line, seven characters
        token = SyntaxFactory.ParseTokens("|||||||").First()
        Assert.Equal(SyntaxKind.EndOfFileToken, token.Kind())
        Assert.True(token.HasLeadingTrivia)
        Assert.True(token.LeadingTrivia.Single().Kind() = SyntaxKind.ConflictMarkerTrivia)

        ' Start of line, seven characters
        token = SyntaxFactory.ParseTokens("||||||| trailing chars").First()
        Assert.Equal(SyntaxKind.EndOfFileToken, token.Kind())
        Assert.True(token.HasLeadingTrivia)
        Dim trivia = token.LeadingTrivia.Single()
        Assert.True(trivia.Kind() = SyntaxKind.ConflictMarkerTrivia)
        Assert.Equal(trivia.Span.Length, 22)

        Assert.True(trivia.ContainsDiagnostics)
        Dim err = trivia.Errors().First
        Assert.Equal(ERRID.ERR_Merge_conflict_marker_encountered, err.Code)

        token = SyntaxFactory.ParseTokens("||||||| Trailing" & vbCrLf & "disabled text").First()
        Assert.Equal(SyntaxKind.EndOfFileToken, token.Kind())
        Assert.True(token.HasLeadingTrivia)
        Assert.Equal(3, token.LeadingTrivia.Count)
        trivia = token.LeadingTrivia(0)
        Assert.True(trivia.Kind() = SyntaxKind.ConflictMarkerTrivia)
        Assert.Equal(trivia.Span.Length, 16)

        Assert.True(trivia.ContainsDiagnostics)
        err = trivia.Errors().First
        Assert.Equal(ERRID.ERR_Merge_conflict_marker_encountered, err.Code)

        trivia = token.LeadingTrivia(1)
        Assert.True(trivia.Kind() = SyntaxKind.EndOfLineTrivia)
        Assert.Equal(trivia.Span.Start, 16)
        Assert.Equal(trivia.Span.Length, 2)

        trivia = token.LeadingTrivia(2)
        Assert.True(trivia.Kind() = SyntaxKind.DisabledTextTrivia)
        Assert.Equal(trivia.Span.Start, 18)
        Assert.Equal(trivia.Span.Length, 13)

        token = SyntaxFactory.ParseTokens("||||||| Trailing" & vbCrLf & "disabled text" & vbCrLf & ">>>> still disabled").First()
        Assert.Equal(SyntaxKind.EndOfFileToken, token.Kind())
        Assert.True(token.HasLeadingTrivia)
        Assert.Equal(3, token.LeadingTrivia.Count)

        trivia = token.LeadingTrivia(0)
        Assert.True(trivia.Kind() = SyntaxKind.ConflictMarkerTrivia)
        Assert.Equal(trivia.Span.Length, 16)

        Assert.True(trivia.ContainsDiagnostics)
        err = trivia.Errors().First
        Assert.Equal(ERRID.ERR_Merge_conflict_marker_encountered, err.Code)

        trivia = token.LeadingTrivia(1)
        Assert.True(trivia.Kind() = SyntaxKind.EndOfLineTrivia)
        Assert.Equal(trivia.Span.Length, 2)

        trivia = token.LeadingTrivia(2)
        Assert.True(trivia.Kind() = SyntaxKind.DisabledTextTrivia)
        Assert.Equal(trivia.Span.Length, 34)

        token = SyntaxFactory.ParseTokens("||||||| Trailing" & vbCrLf & "disabled text" & vbCrLf & ">>>>>>> Actually the end").First()
        Assert.Equal(SyntaxKind.EndOfFileToken, token.Kind())
        Assert.True(token.HasLeadingTrivia)
        Assert.Equal(token.LeadingTrivia.Count, 4)
        Dim trivia1 = token.LeadingTrivia(0)
        Assert.True(trivia1.Kind() = SyntaxKind.ConflictMarkerTrivia)
        Assert.Equal(trivia1.Span.Length, 16)

        Assert.True(trivia1.ContainsDiagnostics)
        err = trivia1.Errors().First
        Assert.Equal(ERRID.ERR_Merge_conflict_marker_encountered, err.Code)

        Dim trivia2 = token.LeadingTrivia(1)
        Assert.True(trivia2.Kind() = SyntaxKind.EndOfLineTrivia)
        Assert.Equal(trivia2.Span.Start, 16)
        Assert.Equal(trivia2.Span.Length, 2)

        Dim trivia3 = token.LeadingTrivia(2)
        Assert.True(trivia3.Kind() = SyntaxKind.DisabledTextTrivia)
        Assert.Equal(trivia3.Span.Start, 18)
        Assert.Equal(trivia3.Span.Length, 15)

        Dim trivia4 = token.LeadingTrivia(3)
        Assert.True(trivia4.Kind() = SyntaxKind.ConflictMarkerTrivia)
        Assert.Equal(trivia4.Span.Start, 33)
        Assert.Equal(trivia4.Span.Length, 24)

        Assert.True(trivia4.ContainsDiagnostics)
        err = trivia4.Errors().First
        Assert.Equal(ERRID.ERR_Merge_conflict_marker_encountered, err.Code)
    End Sub

    <Fact>
    Public Sub TestPipeConflictMarker2()
        ' Has to be the start of a line.
        Dim token = SyntaxFactory.ParseTokens("{" & vbCrLf & " |||||||").Skip(2).First()
        Assert.Equal(SyntaxKind.BadToken, token.Kind())
        Assert.True(token.HasLeadingTrivia)
        Assert.True(token.LeadingTrivia.Single().Kind() = SyntaxKind.WhitespaceTrivia)

        ' Has to have at least seven characters.
        token = SyntaxFactory.ParseTokens("{" & vbCrLf & "|||||| ").Skip(2).First()
        Assert.Equal(SyntaxKind.BadToken, token.Kind())

        ' Start of line, seven characters
        token = SyntaxFactory.ParseTokens("{" & vbCrLf & "|||||||").Skip(2).First()
        Assert.Equal(SyntaxKind.EndOfFileToken, token.Kind())
        Assert.True(token.HasLeadingTrivia)
        Dim trivia = token.LeadingTrivia.Single()
        Assert.True(trivia.Kind() = SyntaxKind.ConflictMarkerTrivia)

        Assert.True(trivia.ContainsDiagnostics)
        Dim err = trivia.Errors().First
        Assert.Equal(ERRID.ERR_Merge_conflict_marker_encountered, err.Code)

        ' Start of line, seven characters
        token = SyntaxFactory.ParseTokens("{" & vbCrLf & "||||||| trailing chars").Skip(2).First()
        Assert.Equal(SyntaxKind.EndOfFileToken, token.Kind())
        Assert.True(token.HasLeadingTrivia)
        trivia = token.LeadingTrivia.Single()
        Assert.True(trivia.Kind() = SyntaxKind.ConflictMarkerTrivia)
        Assert.Equal(trivia.Span.Length, 22)

        Assert.True(trivia.ContainsDiagnostics)
        err = trivia.Errors().First
        Assert.Equal(ERRID.ERR_Merge_conflict_marker_encountered, err.Code)

        token = SyntaxFactory.ParseTokens("{" & vbCrLf & "||||||| Trailing" & vbCrLf & "disabled text").Skip(2).First()
        Assert.Equal(SyntaxKind.EndOfFileToken, token.Kind())
        Assert.True(token.HasLeadingTrivia)
        Assert.Equal(3, token.LeadingTrivia.Count)
        trivia = token.LeadingTrivia(0)
        Assert.True(trivia.Kind() = SyntaxKind.ConflictMarkerTrivia)
        Assert.Equal(trivia.Span.Length, 16)

        Assert.True(trivia.ContainsDiagnostics)
        err = trivia.Errors().First
        Assert.Equal(ERRID.ERR_Merge_conflict_marker_encountered, err.Code)

        trivia = token.LeadingTrivia(1)
        Assert.True(trivia.Kind() = SyntaxKind.EndOfLineTrivia)
        Assert.Equal(trivia.Span.Start, 19)
        Assert.Equal(trivia.Span.Length, 2)

        trivia = token.LeadingTrivia(2)
        Assert.True(trivia.Kind() = SyntaxKind.DisabledTextTrivia)
        Assert.Equal(trivia.Span.Start, 21)
        Assert.Equal(trivia.Span.Length, 13)

        token = SyntaxFactory.ParseTokens("{" & vbCrLf & "||||||| Trailing" & vbCrLf & "disabled text" & vbCrLf & ">>>> still disabled").Skip(2).First()
        Assert.Equal(SyntaxKind.EndOfFileToken, token.Kind())
        Assert.True(token.HasLeadingTrivia)
        Assert.Equal(3, token.LeadingTrivia.Count)

        trivia = token.LeadingTrivia(0)
        Assert.True(trivia.Kind() = SyntaxKind.ConflictMarkerTrivia)
        Assert.Equal(trivia.Span.Length, 16)

        Assert.True(trivia.ContainsDiagnostics)
        err = trivia.Errors().First
        Assert.Equal(ERRID.ERR_Merge_conflict_marker_encountered, err.Code)

        trivia = token.LeadingTrivia(1)
        Assert.True(trivia.Kind() = SyntaxKind.EndOfLineTrivia)
        Assert.Equal(trivia.Span.Length, 2)

        trivia = token.LeadingTrivia(2)
        Assert.True(trivia.Kind() = SyntaxKind.DisabledTextTrivia)
        Assert.Equal(trivia.Span.Length, 34)

        token = SyntaxFactory.ParseTokens("{" & vbCrLf & "||||||| Trailing" & vbCrLf & "disabled text" & vbCrLf & ">>>>>>> Actually the end").Skip(2).First()
        Assert.Equal(SyntaxKind.EndOfFileToken, token.Kind())
        Assert.True(token.HasLeadingTrivia)
        Assert.Equal(token.LeadingTrivia.Count, 4)
        Dim trivia1 = token.LeadingTrivia(0)
        Assert.True(trivia1.Kind() = SyntaxKind.ConflictMarkerTrivia)
        Assert.Equal(trivia1.Span.Length, 16)

        Assert.True(trivia1.ContainsDiagnostics)
        err = trivia1.Errors().First
        Assert.Equal(ERRID.ERR_Merge_conflict_marker_encountered, err.Code)

        Dim trivia2 = token.LeadingTrivia(1)
        Assert.True(trivia2.Kind() = SyntaxKind.EndOfLineTrivia)
        Assert.Equal(trivia2.Span.Start, 19)
        Assert.Equal(trivia2.Span.Length, 2)

        Dim trivia3 = token.LeadingTrivia(2)
        Assert.True(trivia3.Kind() = SyntaxKind.DisabledTextTrivia)
        Assert.Equal(trivia3.Span.Start, 21)
        Assert.Equal(trivia3.Span.Length, 15)

        Dim trivia4 = token.LeadingTrivia(3)
        Assert.True(trivia4.Kind() = SyntaxKind.ConflictMarkerTrivia)
        Assert.Equal(trivia4.Span.Start, 36)
        Assert.Equal(trivia4.Span.Length, 24)

        Assert.True(trivia4.ContainsDiagnostics)
        err = trivia4.Errors().First
        Assert.Equal(ERRID.ERR_Merge_conflict_marker_encountered, err.Code)
    End Sub

    <Fact>
    Public Sub TestPipeConflictMarker3()
        Dim token = SyntaxFactory.ParseTokens("||||||| trailing chars" & vbCrLf & "||||||| more trailing chars").First()
        Assert.Equal(SyntaxKind.EndOfFileToken, token.Kind())
        Assert.True(token.HasLeadingTrivia)
        Assert.Equal(3, token.LeadingTrivia.Count)

        Dim trivia = token.LeadingTrivia(0)
        Assert.True(trivia.Kind() = SyntaxKind.ConflictMarkerTrivia)
        Assert.Equal(trivia.Span.Length, 22)
        Assert.Equal("||||||| trailing chars", trivia.ToFullString())
        Assert.True(trivia.ContainsDiagnostics)
        Assert.Equal(ERRID.ERR_Merge_conflict_marker_encountered, trivia.Errors().First().Code)

        trivia = token.LeadingTrivia(1)
        Assert.True(trivia.Kind() = SyntaxKind.EndOfLineTrivia)
        Assert.Equal(trivia.Span.Start, 22)
        Assert.Equal(trivia.Span.Length, 2)

        trivia = token.LeadingTrivia(2)
        Assert.True(trivia.Kind() = SyntaxKind.DisabledTextTrivia)
        Assert.Equal(trivia.Span.Start, 24)
        Assert.Equal(trivia.Span.Length, 27)
        Assert.Equal("||||||| more trailing chars", trivia.ToFullString())
    End Sub

    <Fact>
    Public Sub TestPipeConflictMarker4()
        Dim token = SyntaxFactory.ParseTokens("||||||| trailing chars" & vbCrLf & "disabled text" & vbCrLf & "======= more trailing chars" & vbCrLf & "more disabled text" & vbCrLf & ">>>>>>> end trailing chars").First()
        Assert.Equal(SyntaxKind.EndOfFileToken, token.Kind())
        Assert.True(token.HasLeadingTrivia)
        Assert.Equal(7, token.LeadingTrivia.Count)

        Dim trivia = token.LeadingTrivia(0)
        Assert.True(trivia.Kind() = SyntaxKind.ConflictMarkerTrivia)
        Assert.Equal("||||||| trailing chars", trivia.ToFullString())
        Assert.Equal(ERRID.ERR_Merge_conflict_marker_encountered, trivia.Errors().First().Code)

        trivia = token.LeadingTrivia(1)
        Assert.True(trivia.Kind() = SyntaxKind.EndOfLineTrivia)

        trivia = token.LeadingTrivia(2)
        Assert.True(trivia.Kind() = SyntaxKind.DisabledTextTrivia)
        Assert.Equal("disabled text" & vbCrLf, trivia.ToFullString())

        trivia = token.LeadingTrivia(3)
        Assert.True(trivia.Kind() = SyntaxKind.ConflictMarkerTrivia)
        Assert.Equal("======= more trailing chars", trivia.ToFullString())
        Assert.Equal(ERRID.ERR_Merge_conflict_marker_encountered, trivia.Errors().First().Code)

        trivia = token.LeadingTrivia(4)
        Assert.True(trivia.Kind() = SyntaxKind.EndOfLineTrivia)

        trivia = token.LeadingTrivia(5)
        Assert.True(trivia.Kind() = SyntaxKind.DisabledTextTrivia)
        Assert.Equal("more disabled text" & vbCrLf, trivia.ToFullString())

        trivia = token.LeadingTrivia(6)
        Assert.True(trivia.Kind() = SyntaxKind.ConflictMarkerTrivia)
        Assert.Equal(">>>>>>> end trailing chars", trivia.ToFullString())
        Assert.Equal(ERRID.ERR_Merge_conflict_marker_encountered, trivia.Errors().First().Code)
    End Sub

    <Fact>
    Public Sub Scanner_EndOfText()
        Dim tk = ScanOnce("")
        Assert.Equal(SyntaxKind.EndOfFileToken, tk.Kind)
        Assert.Equal("", tk.ToFullString())

        tk = ScanOnce(" ")
        Assert.Equal(SyntaxKind.EndOfFileToken, tk.Kind)
        Assert.Equal(" ", tk.ToFullString())

        tk = ScanOnce("  ")
        Assert.Equal(SyntaxKind.EndOfFileToken, tk.Kind)
        Assert.Equal("  ", tk.ToFullString())

        tk = ScanOnce("'")
        Assert.Equal(SyntaxKind.EmptyToken, tk.Kind)
        Assert.Equal(SyntaxKind.CommentTrivia, tk.TrailingTrivia(0).Kind)
        Assert.Equal("'", tk.ToFullString())

        tk = ScanOnce("'", startStatement:=True)
        Assert.Equal(SyntaxKind.EndOfFileToken, tk.Kind)
        Assert.Equal(SyntaxKind.CommentTrivia, tk.LeadingTrivia(0).Kind)
        Assert.Equal("'", tk.ToFullString())

        tk = ScanOnce(" ' ")
        Assert.Equal(SyntaxKind.EmptyToken, tk.Kind)
        Assert.Equal(SyntaxKind.WhitespaceTrivia, tk.LeadingTrivia(0).Kind)
        Assert.Equal(SyntaxKind.CommentTrivia, tk.TrailingTrivia(0).Kind)
        Assert.Equal(" ", tk.LeadingTrivia(0).ToString())
        Assert.Equal("' ", tk.TrailingTrivia(0).ToString())
        Assert.Equal(" ' ", tk.ToFullString())

        tk = ScanOnce(" ' ", startStatement:=True)
        Assert.Equal(SyntaxKind.EndOfFileToken, tk.Kind)
        Assert.Equal(SyntaxKind.WhitespaceTrivia, tk.LeadingTrivia(0).Kind)
        Assert.Equal(SyntaxKind.CommentTrivia, tk.LeadingTrivia(1).Kind)
        Assert.Equal(" ", tk.LeadingTrivia(0).ToString())
        Assert.Equal("' ", tk.LeadingTrivia(1).ToString())
        Assert.Equal(" ' ", tk.ToFullString())
    End Sub

    <Fact>
    Public Sub Scanner_StatementTerminator()
        Dim tk = ScanOnce(vbCr)
        Assert.Equal(SyntaxKind.EmptyToken, tk.Kind)
        Assert.Equal(vbCr, tk.ToFullString())

        tk = ScanOnce(vbCr, startStatement:=True)
        Assert.Equal(SyntaxKind.EndOfFileToken, tk.Kind)
        Assert.Equal(vbCr, tk.ToFullString())

        Dim tks = ScanAllCheckDw(vbCr)
        Assert.Equal(1, tks.Count)
        Assert.Equal(SyntaxKind.EndOfFileToken, tks(0).Kind)
        Assert.Equal(vbCr, tks(0).ToFullString())

        tks = ScanAllCheckDw(" " & vbLf)
        Assert.Equal(1, tks.Count)
        Assert.Equal(SyntaxKind.EndOfFileToken, tks(0).Kind)
        Assert.Equal(" " & vbLf, tks(0).ToFullString())

        tks = ScanAllCheckDw(" A" & vbCrLf & " ")
        Assert.Equal(3, tks.Count)
        Assert.Equal(SyntaxKind.IdentifierToken, tks(0).Kind)
        Assert.Equal(" A" & vbCrLf, tks(0).ToFullString())
        Assert.Equal(SyntaxKind.StatementTerminatorToken, tks(1).Kind)
        Assert.Equal("", tks(1).ToFullString())
        Assert.Equal(SyntaxKind.EndOfFileToken, tks(2).Kind)
        Assert.Equal(" ", tks(2).ToFullString())
    End Sub

    <Fact>
    Public Sub Scanner_StartStatement()
        Dim tk = ScanOnce(vbCr, startStatement:=True)
        Assert.Equal(SyntaxKind.EndOfFileToken, tk.Kind)
        Assert.Equal(vbCr, tk.ToFullString())

        tk = ScanOnce(" " & vbLf, startStatement:=True)
        Assert.Equal(SyntaxKind.EndOfFileToken, tk.Kind)
        Assert.Equal(" " & vbLf, tk.ToFullString())

        Dim str = " " & vbCrLf & " " & vbCr & "'2  " & vbLf & " ("
        tk = ScanOnce(str, startStatement:=True)
        Assert.Equal(SyntaxKind.OpenParenToken, tk.Kind)
        Assert.Equal(str, tk.ToFullString())

        str = "'("
        tk = ScanOnce(str, startStatement:=True)
        Assert.Equal(SyntaxKind.EndOfFileToken, tk.Kind)
        Assert.Equal(str, tk.ToFullString())

        str = "'" & vbCrLf & "("
        tk = ScanOnce(str, startStatement:=False)
        Assert.Equal(SyntaxKind.EmptyToken, tk.Kind)
        Assert.Equal("'" & vbCrLf, tk.ToFullString())

        str = "'" & vbCrLf & "("
        tk = ScanOnce(str, startStatement:=True)
        Assert.Equal(SyntaxKind.OpenParenToken, tk.Kind)
        Assert.Equal(str, tk.ToFullString())

        str = "' " & vbCrLf & "  '(" & vbCrLf & "("
        tk = ScanOnce(str, startStatement:=True)
        Assert.Equal(SyntaxKind.OpenParenToken, tk.Kind)
        Assert.Equal(str, tk.ToFullString())
    End Sub

    <Fact>
    Public Sub Scanner_LineContWhenExpectingNewStatement()
        Dim tk = ScanOnce("_", startStatement:=True)
        Assert.Equal(SyntaxKind.EndOfFileToken, tk.Kind)
        Assert.Equal("_", tk.ToFullString())

        tk = ScanOnce(" _", startStatement:=True)
        Assert.Equal(SyntaxKind.EndOfFileToken, tk.Kind)
        Assert.Equal(" _", tk.ToFullString())

        tk = ScanOnce(" _ ", startStatement:=True)
        Assert.Equal(SyntaxKind.EndOfFileToken, tk.Kind)
        Assert.Equal(" _ ", tk.ToFullString())

        tk = ScanOnce(" _'", startStatement:=True)
        Assert.Equal(SyntaxKind.EndOfFileToken, tk.Kind)
        Assert.Equal(" _'", tk.ToFullString())
        Assert.Equal(3, tk.LeadingTrivia.Count)
        Assert.Equal(SyntaxKind.WhitespaceTrivia, tk.LeadingTrivia(0).Kind)
        Assert.Equal(SyntaxKind.LineContinuationTrivia, tk.LeadingTrivia(1).Kind)
        Assert.Equal(SyntaxKind.CommentTrivia, tk.LeadingTrivia(2).Kind)
        Assert.Equal(0, tk.Errors.Count)

        tk = ScanOnce(" _'", LanguageVersion.VisualBasic16)
        Assert.Equal(SyntaxKind.EndOfFileToken, tk.Kind)
        Assert.Equal(" _'", tk.ToFullString())
        Assert.Equal(3, tk.LeadingTrivia.Count)
        Assert.Equal(SyntaxKind.WhitespaceTrivia, tk.LeadingTrivia(0).Kind)
        Assert.Equal(SyntaxKind.LineContinuationTrivia, tk.LeadingTrivia(1).Kind)
        Assert.Equal(SyntaxKind.CommentTrivia, tk.LeadingTrivia(2).Kind)
        Assert.Equal(0, tk.Errors.Count)

        tk = ScanOnce(" _' Comment", LanguageVersion.VisualBasic15_3)
        Assert.Equal(SyntaxKind.EndOfFileToken, tk.Kind)
        Assert.Equal(" _' Comment", tk.ToFullString())
        Assert.Equal(3, tk.LeadingTrivia.Count)
        Assert.Equal(SyntaxKind.WhitespaceTrivia, tk.LeadingTrivia(0).Kind)
        Assert.False(tk.LeadingTrivia(0).ContainsDiagnostics)
        Assert.Equal(SyntaxKind.LineContinuationTrivia, tk.LeadingTrivia(1).Kind)
        Assert.False(tk.LeadingTrivia(1).ContainsDiagnostics)
        Assert.Equal(SyntaxKind.CommentTrivia, tk.LeadingTrivia(2).Kind)
        Assert.True(tk.LeadingTrivia(2).ContainsDiagnostics)
        Assert.Equal(1, tk.Errors.Count)
        Assert.Equal(ERRID.ERR_CommentsAfterLineContinuationNotAvailable1, tk.Errors.First().Code)

        tk = ScanOnce(" _' Comment", LanguageVersion.VisualBasic16)
        Assert.Equal(SyntaxKind.EndOfFileToken, tk.Kind)
        Assert.Equal(" _' Comment", tk.ToFullString())
        Assert.Equal(3, tk.LeadingTrivia.Count)
        Assert.Equal(SyntaxKind.WhitespaceTrivia, tk.LeadingTrivia(0).Kind)
        Assert.Equal(SyntaxKind.LineContinuationTrivia, tk.LeadingTrivia(1).Kind)
        Assert.Equal(SyntaxKind.CommentTrivia, tk.LeadingTrivia(2).Kind)
        Assert.Equal(0, tk.Errors.Count)

        tk = ScanOnce(" _  ' Comment" & vbCrLf, LanguageVersion.VisualBasic16)
        Assert.Equal(SyntaxKind.EndOfFileToken, tk.Kind)
        Assert.Equal(" _  ' Comment" & vbCrLf, tk.ToFullString())
        Assert.Equal(5, tk.LeadingTrivia.Count)
        Assert.Equal(SyntaxKind.WhitespaceTrivia, tk.LeadingTrivia(0).Kind)
        Assert.Equal(SyntaxKind.LineContinuationTrivia, tk.LeadingTrivia(1).Kind)
        Assert.Equal(SyntaxKind.WhitespaceTrivia, tk.LeadingTrivia(2).Kind)
        Assert.Equal(SyntaxKind.CommentTrivia, tk.LeadingTrivia(3).Kind)
        Assert.Equal(SyntaxKind.EndOfLineTrivia, tk.LeadingTrivia(4).Kind)
        Assert.Equal(0, tk.Errors.Count)

        tk = ScanOnce(" _ rem", startStatement:=True)
        Assert.Equal(SyntaxKind.BadToken, tk.Kind)
        Assert.Equal(" _ rem", tk.ToFullString())
        Assert.Equal(30999, tk.Errors.First().Code)

        tk = ScanOnce(" _ abc", startStatement:=True)
        Assert.Equal(SyntaxKind.BadToken, tk.Kind)
        Assert.Equal(" _ ", tk.ToFullString())
        Assert.Equal(30203, tk.Errors.First().Code)

        Dim tks = ScanAllCheckDw(" _ rem")
        Assert.Equal(SyntaxKind.BadToken, tks(0).Kind)
        Assert.Equal(" _ rem", tks(0).ToFullString())
        Assert.Equal(30999, tks(0).Errors.First().Code)

        tk = ScanOnce("_" & vbLf, startStatement:=True)
        Assert.Equal(SyntaxKind.EndOfFileToken, tk.Kind)
        Assert.Equal("_" & vbLf, tk.ToFullString())

        tk = ScanOnce(" _" & vbLf, startStatement:=True)
        Assert.Equal(SyntaxKind.EndOfFileToken, tk.Kind)
        Assert.Equal(" _" & vbLf, tk.ToFullString())

        Dim str = " _" & vbCrLf & " _" & vbCr & "'2  " & vbLf & " ("
        tk = ScanOnce(str, startStatement:=True)
        Assert.Equal(SyntaxKind.OpenParenToken, tk.Kind)
        Assert.Equal(str, tk.ToFullString())

        str = " _" & vbCrLf & " _" & vbCrLf & "("
        tk = ScanOnce(str, startStatement:=True)
        Assert.Equal(SyntaxKind.OpenParenToken, tk.Kind)
        Assert.Equal(str, tk.ToFullString())
    End Sub

    <Fact>
    Public Sub Scanner_LineContInsideStatement()

        ' this would be a case of      )_
        ' valid _ would have been consumed by   )
        Dim tk = ScanOnce("_" & vbLf, False)
        Assert.Equal(SyntaxKind.BadToken, tk.Kind)
        Assert.Equal("_" + vbLf, tk.ToFullString)

        Dim Str = "'_" & vbCrLf & "("
        tk = ScanOnce(Str, False)
        Assert.Equal(SyntaxKind.EmptyToken, tk.Kind)
        Assert.Equal("'_" & vbCrLf, tk.ToFullString())

        Str = " _" & vbCrLf & "("
        tk = ScanOnce(Str, False)
        Assert.Equal(SyntaxKind.OpenParenToken, tk.Kind)
        Assert.Equal(Str, tk.ToFullString())

        ' _ is invalid here, should not be consumed by (
        Str = " _" & vbCrLf & "(" & "_" & vbCrLf & "'qq"
        tk = ScanOnce(Str, False)
        Assert.Equal(SyntaxKind.OpenParenToken, tk.Kind)
        Assert.Equal(" _" & vbCrLf & "(", tk.ToFullString())

        ' _ is valid here, but we should not go past the Eol
        Str = " _" & vbCrLf & "(" & " _" & vbCrLf & "'qq"
        tk = ScanOnce(Str, False)
        Assert.Equal(SyntaxKind.OpenParenToken, tk.Kind)
        Assert.Equal(" _" & vbCrLf & "(" & " _" & vbCrLf, tk.ToFullString())

    End Sub

    <Fact>
    Public Sub Scanner_RemComment()
        Dim str = " " & vbCrLf & " " & vbCr & "REM  " & vbLf & " ("
        Dim tk = ScanOnce(str, True)
        Assert.Equal(SyntaxKind.OpenParenToken, tk.Kind)
        Assert.Equal(str, tk.ToFullString())

        str = "A REM Hello "
        tk = ScanOnce(str, True)
        Assert.Equal(SyntaxKind.IdentifierToken, tk.Kind)
        Assert.Equal(str, tk.ToFullString())

        str = "A A REM Hello " & vbCrLf & "A Rem Hello                                                             "
        Dim tks = ScanAllCheckDw(str)
        Assert.Equal(SyntaxKind.IdentifierToken, tks(0).Kind)
        Assert.Equal("A ", tks(0).ToFullString)
        Assert.Equal(SyntaxKind.IdentifierToken, tks(1).Kind)
        Assert.NotEqual("A ", tks(1).ToFullString)
        Assert.Equal(SyntaxKind.StatementTerminatorToken, tks(2).Kind)
        Assert.Equal(SyntaxKind.IdentifierToken, tks(3).Kind)
        Assert.NotEqual("A ", tks(1).ToFullString)
        Assert.Equal(SyntaxKind.EndOfFileToken, tks(4).Kind)
        Assert.Equal(5, tks.Count)

        REM(
        str = "REM("
        tk = ScanOnce(str, True)
        Assert.Equal(SyntaxKind.EndOfFileToken, tk.Kind)
        Assert.Equal(str, tk.ToFullString())

        str = "ReM" & vbCrLf & "("
        tk = ScanOnce(str, False)
        Assert.Equal(SyntaxKind.EmptyToken, tk.Kind)
        Assert.Equal("ReM" & vbCrLf, tk.ToFullString())

        str = "rEM" & vbCrLf & "("
        tk = ScanOnce(str, True)
        Assert.Equal(SyntaxKind.OpenParenToken, tk.Kind)
        Assert.Equal(str, tk.ToFullString())

        str = "rem " & vbCrLf & "  REM(" & vbCrLf & "("
        tk = ScanOnce(str, True)
        Assert.Equal(SyntaxKind.OpenParenToken, tk.Kind)
        Assert.Equal(str, tk.ToFullString())
    End Sub

    ''' <summary>
    ''' EmptyToken is generated by the Scanner in a single-line
    ''' If or lambda with an empty statement to avoid generating
    ''' a statement terminator with leading or trailing trivia.
    ''' </summary>
    <Fact>
    Public Sub Scanner_EmptyToken()
        ' No EmptyToken required because no trivia before EOF.
        ParseTokensAndVerify("If True Then Else Return :",
                             SyntaxKind.IfKeyword,
                             SyntaxKind.TrueKeyword,
                             SyntaxKind.ThenKeyword,
                             SyntaxKind.ElseKeyword,
                             SyntaxKind.ReturnKeyword,
                             SyntaxKind.ColonToken,
                             SyntaxKind.EndOfFileToken)
        ' No EmptyToken required because no trailing trivia before EOF.
        ' (The space after the colon is leading trivia on EOF.)
        ParseTokensAndVerify("If True Then Else : ",
                             SyntaxKind.IfKeyword,
                             SyntaxKind.TrueKeyword,
                             SyntaxKind.ThenKeyword,
                             SyntaxKind.ElseKeyword,
                             SyntaxKind.ColonToken,
                             SyntaxKind.EndOfFileToken)
        ' EmptyToken required because comment is trailing
        ' trivia between the colon and EOL.
        ParseTokensAndVerify(<![CDATA[If True Then Else :'Comment
Return]]>.Value,
                             SyntaxKind.IfKeyword,
                             SyntaxKind.TrueKeyword,
                             SyntaxKind.ThenKeyword,
                             SyntaxKind.ElseKeyword,
                             SyntaxKind.ColonToken,
                             SyntaxKind.EmptyToken,
                             SyntaxKind.StatementTerminatorToken,
                             SyntaxKind.ReturnKeyword,
                             SyntaxKind.EndOfFileToken)
        ' EmptyToken required because comment is trailing
        ' trivia between the colon and EOF.
        ParseTokensAndVerify("Sub() If True Then Return : REM",
                             SyntaxKind.SubKeyword,
                             SyntaxKind.OpenParenToken,
                             SyntaxKind.CloseParenToken,
                             SyntaxKind.IfKeyword,
                             SyntaxKind.TrueKeyword,
                             SyntaxKind.ThenKeyword,
                             SyntaxKind.ReturnKeyword,
                             SyntaxKind.ColonToken,
                             SyntaxKind.EmptyToken,
                             SyntaxKind.EndOfFileToken)
        ' No EmptyToken required because colon, space, comment
        ' and EOL are all treated as multi-line leading trivia on EndKeyword.
        ParseTokensAndVerify(<![CDATA[If True Then
: 'Comment
End If]]>.Value,
                             SyntaxKind.IfKeyword,
                             SyntaxKind.TrueKeyword,
                             SyntaxKind.ThenKeyword,
                             SyntaxKind.StatementTerminatorToken,
                             SyntaxKind.EndKeyword,
                             SyntaxKind.IfKeyword,
                             SyntaxKind.EndOfFileToken)
    End Sub

    Private Sub ParseTokensAndVerify(str As String, ParamArray kinds As SyntaxKind())
        Dim tokens = SyntaxFactory.ParseTokens(str).ToArray()
        Dim result = String.Join("", tokens.Select(Function(t) t.ToFullString()))
        Assert.Equal(str, result)
        Assert.Equal(tokens.Length, kinds.Length)
        For i = 0 To tokens.Length - 1
            Assert.Equal(tokens(i).Kind, kinds(i))
        Next
    End Sub

    <Fact>
    Public Sub Scanner_DimKeyword()
        Dim Str = " " & vbCrLf & " " & vbCr & "DIM  " & vbLf & " ("
        Dim tk = ScanOnce(Str, True)
        Assert.Equal(SyntaxKind.DimKeyword, tk.Kind)
        Assert.Equal(" " & vbCrLf & " " & vbCr & "DIM  " + vbLf, tk.ToFullString)

        Str = "Dim("
        tk = ScanOnce(Str, True)
        Assert.Equal(SyntaxKind.DimKeyword, tk.Kind)
        Assert.Equal("Dim", tk.ToFullString())

        Str = "DiM" & vbCrLf & "("
        tk = ScanOnce(Str, False)
        Assert.Equal(SyntaxKind.DimKeyword, tk.Kind)
        Assert.Equal("DiM" + vbCrLf, tk.ToFullString)

        Str = "dIM" & " _" & vbCrLf & "("
        tk = ScanOnce(Str, True)
        Assert.Equal(SyntaxKind.DimKeyword, tk.Kind)
        Assert.Equal("dIM" & " _" & vbCrLf, tk.ToFullString())

        Str = "dim " & vbCrLf & "  DIMM" & vbCrLf & "("
        Dim tks = ScanAllNoDwCheck(Str)

        Assert.Equal(SyntaxKind.DimKeyword, tks(0).Kind)
        Assert.Equal(SyntaxKind.StatementTerminatorToken, tks(1).Kind)
        Assert.Equal(SyntaxKind.IdentifierToken, tks(2).Kind)
        Assert.Equal(SyntaxKind.StatementTerminatorToken, tks(3).Kind)
        Assert.Equal(SyntaxKind.OpenParenToken, tks(4).Kind)
    End Sub

    <WorkItem(15925, "DevDiv_Projects/Roslyn")>
    <Fact>
    Public Sub StaticKeyword()
        Dim Str = " " & vbCrLf & " " & vbCr & "STATIC  " & vbLf & " ("
        Dim tk = ScanOnce(Str, True)
        Assert.Equal(SyntaxKind.StaticKeyword, tk.Kind)
        Assert.Equal(" " & vbCrLf & " " & vbCr & "STATIC  " & vbLf, tk.ToFullString())

        Str = "Static("
        tk = ScanOnce(Str, True)
        Assert.Equal(SyntaxKind.StaticKeyword, tk.Kind)
        Assert.Equal("Static", tk.ToFullString())

        Str = "StatiC" & vbCrLf & "("
        tk = ScanOnce(Str, False)
        Assert.Equal(SyntaxKind.StaticKeyword, tk.Kind)
        Assert.Equal("StatiC" & vbCrLf, tk.ToFullString())

        Str = "sTATIC" & " _" & vbCrLf & "("
        tk = ScanOnce(Str, True)
        Assert.Equal(SyntaxKind.StaticKeyword, tk.Kind)
        Assert.Equal("sTATIC" & " _" & vbCrLf, tk.ToFullString())

        Str = "static " & vbCrLf & "  STATICC" & vbCrLf & "("
        Dim tks = ScanAllNoDwCheck(Str)

        Assert.Equal(SyntaxKind.StaticKeyword, tks(0).Kind)
        Assert.Equal(SyntaxKind.StatementTerminatorToken, tks(1).Kind)
        Assert.Equal(SyntaxKind.IdentifierToken, tks(2).Kind)
        Assert.Equal(SyntaxKind.StatementTerminatorToken, tks(3).Kind)
        Assert.Equal(SyntaxKind.OpenParenToken, tks(4).Kind)
    End Sub
    <Fact>
    Public Sub Scanner_FrequentKeywords()
        Dim Str = "End "
        Dim tk = ScanOnce(Str, True)
        Assert.Equal(SyntaxKind.EndKeyword, tk.Kind)
        Assert.Equal(3, tk.Span.Length)
        Assert.Equal(4, tk.FullSpan.Length)
        Assert.Equal("End ", tk.ToFullString())

        Str = "As "
        tk = ScanOnce(Str, False)
        Assert.Equal(SyntaxKind.AsKeyword, tk.Kind)
        Assert.Equal(2, tk.Span.Length)
        Assert.Equal(3, tk.FullSpan.Length)
        Assert.Equal("As ", tk.ToFullString())

        Str = "If "
        tk = ScanOnce(Str, False)
        Assert.Equal(SyntaxKind.IfKeyword, tk.Kind)
        Assert.Equal(2, tk.Span.Length)
        Assert.Equal(3, tk.FullSpan.Length)
        Assert.Equal("If ", tk.ToFullString())
    End Sub

    <Fact>
    Public Sub Scanner_PlusToken()
        Dim Str = "+"
        Dim tk = ScanOnce(Str, True)
        Assert.Equal(SyntaxKind.PlusToken, tk.Kind)
        Assert.Equal(Str, tk.ToFullString())

        Str = "+    ="
        tk = ScanOnce(Str, True)
        Assert.Equal(SyntaxKind.PlusEqualsToken, tk.Kind)
        Assert.Equal(Str, tk.ToFullString())
    End Sub

    <Fact>
    Public Sub Scanner_PowerToken()
        Dim Str = "^"
        Dim tk = ScanOnce(Str, False)
        Assert.Equal(SyntaxKind.CaretToken, tk.Kind)
        Assert.Equal(Str, tk.ToFullString())

        Str = "^    =^"
        Dim tks = ScanAllCheckDw(Str)
        Assert.Equal(SyntaxKind.CaretEqualsToken, tks(0).Kind)
        Assert.Equal(SyntaxKind.CaretToken, tks(1).Kind)
    End Sub

    <Fact>
    Public Sub Scanner_GreaterThanToken()
        Dim Str = ">  "
        Dim tk = ScanOnce(Str, False)
        Assert.Equal(SyntaxKind.GreaterThanToken, tk.Kind)
        Assert.Equal(Str, tk.ToFullString())

        Str = "  >= 'qqqq"
        tk = ScanOnce(Str, True)
        Assert.Equal(SyntaxKind.GreaterThanEqualsToken, tk.Kind)
        Assert.Equal(Str, tk.ToFullString())

        Str = "  >  ="
        tk = ScanOnce(Str, True)
        Assert.Equal(SyntaxKind.GreaterThanEqualsToken, tk.Kind)
        Assert.Equal(Str, tk.ToFullString())

        'Str = " >" & vbCrLf & "="
        'tk = ScanOnce(Str, True)
        'Assert.Equal(NodeKind.GreaterToken, tk.Kind)
        'Assert.Equal(" >" & vbCrLf, tk.ToFullString())

        'Str = ">" & " _" & vbCrLf & "="
        'tk = ScanOnce(Str, True)
        'Assert.Equal(NodeKind.GreaterToken, tk.Kind)
        'Assert.Equal(">" & " _" & vbCrLf, tk.ToFullString())
    End Sub

    <Fact>
    Public Sub Scanner_LessThanToken()
        Dim Str = ">  <"
        Dim tks = ScanAllCheckDw(Str)
        Assert.Equal(SyntaxKind.GreaterThanToken, tks(0).Kind)
        Assert.Equal(SyntaxKind.LessThanToken, tks(1).Kind)

        Str = "<<<<%"
        tks = ScanAllCheckDw(Str)
        Assert.Equal(SyntaxKind.LessThanLessThanToken, tks(0).Kind)
        Assert.Equal(SyntaxKind.LessThanToken, tks(1).Kind)
        Assert.Equal(SyntaxKind.LessThanToken, tks(2).Kind)
        Assert.Equal(SyntaxKind.BadToken, tks(3).Kind)
        Assert.Equal(SyntaxKind.EndOfFileToken, tks(4).Kind)

        Str = " <   << <% "
        tks = ScanAllCheckDw(Str)
        Assert.Equal(SyntaxKind.LessThanLessThanToken, tks(0).Kind)
        Assert.Equal(SyntaxKind.LessThanToken, tks(1).Kind)
        Assert.Equal(SyntaxKind.LessThanToken, tks(2).Kind)
        Assert.Equal(SyntaxKind.BadToken, tks(3).Kind)
        Assert.Equal(SyntaxKind.EndOfFileToken, tks(4).Kind)
    End Sub

    <Fact>
    Public Sub Scanner_ShiftLeftToken()
        Dim Str = "<<<<="
        Dim tks = ScanAllCheckDw(Str)
        Assert.Equal(SyntaxKind.LessThanLessThanToken, tks(0).Kind)
        Assert.Equal(SyntaxKind.LessThanLessThanEqualsToken, tks(1).Kind)
        Assert.Equal(SyntaxKind.EndOfFileToken, tks(2).Kind)

        'Str = "<" & vbLf & " < < = "
        'tks = ScanAllCheckDw(Str)
        'Assert.Equal(NodeKind.LessToken, tks(0).Kind)
        'Assert.Equal(NodeKind.LeftShiftEqualsToken, tks(1).Kind)
        'Assert.Equal(NodeKind.EndOfTextToken, tks(2).Kind)

        '' left shift does not allow implicit line continuation
        'Str = "<<" & vbLf & "<<="
        'tks = ScanAllCheckDw(Str)
        'Assert.Equal(NodeKind.LeftShiftToken, tks(0).Kind)
        'Assert.Equal(NodeKind.StatementTerminatorToken, tks(1).Kind)
        'Assert.Equal(NodeKind.LeftShiftEqualsToken, tks(2).Kind)
        'Assert.Equal(NodeKind.EndOfTextToken, tks(3).Kind)
    End Sub

    <Fact>
    Public Sub Scanner_NotEqualsToken()
        Dim Str = "<>"
        Dim tks = ScanAllCheckDw(Str)
        Assert.Equal(SyntaxKind.LessThanGreaterThanToken, tks(0).Kind)
        Assert.Equal(SyntaxKind.EndOfFileToken, tks(1).Kind)

        Str = "<>="
        tks = ScanAllCheckDw(Str)
        Assert.Equal(SyntaxKind.LessThanGreaterThanToken, tks(0).Kind)
        Assert.Equal(SyntaxKind.EqualsToken, tks(1).Kind)
        Assert.Equal(SyntaxKind.EndOfFileToken, tks(2).Kind)

        'Str = "<" & vbLf & " > "
        'tks = ScanAllCheckDw(Str)
        'Assert.Equal(NodeKind.LessToken, tks(0).Kind)
        'Assert.Equal(NodeKind.GreaterToken, tks(1).Kind)
        'Assert.Equal(NodeKind.EndOfTextToken, tks(2).Kind)

        '' left shift does not allow implicit line continuation
        'Str = "<    > <" & " _" & vbLf & ">"
        'tks = ScanAllCheckDw(Str)
        'Assert.Equal(NodeKind.NotEqualToken, tks(0).Kind)
        'Assert.Equal(NodeKind.LessToken, tks(1).Kind)
        'Assert.Equal(NodeKind.GreaterToken, tks(2).Kind)
        'Assert.Equal(NodeKind.EndOfTextToken, tks(3).Kind)
    End Sub

    Private Sub CheckCharTkValue(tk As SyntaxToken, expected As Char)
        Dim val = DirectCast(tk.Value, Char)
        Assert.Equal(expected, val)
    End Sub

    <Fact>
    Public Sub Scanner_CharLiteralToken()
        Dim Str = <text>"Q"c</text>.Value
        Dim tk = ScanOnce(Str)
        Assert.Equal(SyntaxKind.CharacterLiteralToken, tk.Kind)
        Assert.Equal(Str, tk.ToFullString())
        CheckCharTkValue(tk, "Q"c)

        Str = <text>""""c</text>.Value
        tk = ScanOnce(Str)
        Assert.Equal(SyntaxKind.CharacterLiteralToken, tk.Kind)
        Assert.Equal(Str, tk.ToFullString())
        CheckCharTkValue(tk, """"c)

        Str = <text>""c</text>.Value
        tk = ScanOnce(Str)
        Assert.Equal(SyntaxKind.BadToken, tk.Kind)
        Assert.Equal(30004, tk.GetSyntaxErrorsNoTree()(0).Code)
        Assert.Equal(Str, tk.ToFullString())

        Str = <text>"""c</text>.Value
        tk = ScanOnce(Str)
        Assert.Equal(SyntaxKind.StringLiteralToken, tk.Kind)
        Assert.Equal(30648, tk.GetSyntaxErrorsNoTree()(0).Code)
        Assert.Equal(Str, tk.ToFullString())
        CheckStrTkValue(tk, """c")

        Str = <text>"QQ"c</text>.Value
        tk = ScanOnce(Str)
        Assert.Equal(SyntaxKind.BadToken, tk.Kind)
        Assert.Equal(30004, tk.GetSyntaxErrorsNoTree()(0).Code)
        Assert.Equal(Str, tk.ToFullString())

        Str = <text>"Q"c "Q"c"Q"c   "Q"c _
"Q"c
""""c</text>.Value

        Dim doubleWidthStr = MakeDwString(Str)
        Dim tks = ScanAllNoDwCheck(doubleWidthStr)
        Assert.Equal(10, tks.Count)
        Assert.Equal(True, tks.Any(Function(t) t.ContainsDiagnostics))
    End Sub

    Private Sub CheckStrTkValue(tk As SyntaxToken, expected As String)
        Dim str = DirectCast(tk.Value, String)
        Assert.Equal(expected, str)
    End Sub

    <Fact>
    Public Sub Scanner_StringLiteralToken()
        Dim Str = <text>""</text>.Value
        Dim tk = ScanOnce(Str)
        Assert.Equal(SyntaxKind.StringLiteralToken, tk.Kind)
        Assert.Equal(Str, tk.ToFullString())
        CheckStrTkValue(tk, "")

        Str = <text>"Q"</text>.Value
        tk = ScanOnce(Str)
        Assert.Equal(SyntaxKind.StringLiteralToken, tk.Kind)
        Assert.Equal(Str, tk.ToFullString())
        CheckStrTkValue(tk, "Q")

        Str = <text>""""</text>.Value
        tk = ScanOnce(Str)
        Assert.Equal(SyntaxKind.StringLiteralToken, tk.Kind)
        Assert.Equal(Str, tk.ToFullString())
        CheckStrTkValue(tk, """")

        Str = <text>""""""""</text>.Value
        tk = ScanOnce(Str)
        Assert.Equal(SyntaxKind.StringLiteralToken, tk.Kind)
        Assert.Equal(Str, tk.ToFullString())
        CheckStrTkValue(tk, """""""")

        Str = <text>"""" """"</text>.Value
        Dim tks = ScanAllCheckDw(Str)
        Assert.Equal(SyntaxKind.StringLiteralToken, tks(0).Kind)
        Assert.Equal(SyntaxKind.StringLiteralToken, tks(1).Kind)

        Str = <text>"AA"
"BB"</text>.Value
        tks = ScanAllCheckDw(Str)
        Assert.Equal(SyntaxKind.StringLiteralToken, tks(0).Kind)
        Assert.Equal(SyntaxKind.StatementTerminatorToken, tks(1).Kind)
        Assert.Equal(SyntaxKind.StringLiteralToken, tks(2).Kind)
    End Sub

    <Fact>
    Public Sub Scanner_IntegerLiteralToken()
        Dim Str = "42"
        Dim tk = ScanOnce(Str)
        Assert.Equal(SyntaxKind.IntegerLiteralToken, tk.Kind)
        Assert.Equal(LiteralBase.Decimal, tk.GetBase())
        Assert.Equal(42, tk.Value)

        Str = " 42 "
        tk = ScanOnce(Str)
        Assert.Equal(SyntaxKind.IntegerLiteralToken, tk.Kind)
        Assert.Equal(LiteralBase.Decimal, tk.GetBase())
        Assert.Equal(42, tk.Value)
        Assert.Equal(" 42 ", tk.ToFullString())

        Str = " 4_2 "
        tk = ScanOnce(Str)
        Assert.Equal(SyntaxKind.IntegerLiteralToken, tk.Kind)
        Assert.Equal(LiteralBase.Decimal, tk.GetBase())
        Assert.Equal(42, tk.Value)
        Assert.Equal(" 4_2 ", tk.ToFullString())
        Assert.Equal(0, tk.Errors().Count)

        Str = " &H42L "
        tk = ScanOnce(Str)
        Assert.Equal(SyntaxKind.IntegerLiteralToken, tk.Kind)
        Assert.Equal(LiteralBase.Hexadecimal, tk.GetBase())
        Assert.Equal(&H42L, tk.Value)
        Assert.Equal(" &H42L ", tk.ToFullString())

        Str = " &H4_2L "
        tk = ScanOnce(Str)
        Assert.Equal(SyntaxKind.IntegerLiteralToken, tk.Kind)
        Assert.Equal(LiteralBase.Hexadecimal, tk.GetBase())
        Assert.Equal(&H42L, tk.Value)
        Assert.Equal(" &H4_2L ", tk.ToFullString())

        Str = " &H_1 "
        tk = ScanOnce(Str)
        Assert.Equal(SyntaxKind.IntegerLiteralToken, tk.Kind)
        Assert.Equal(LiteralBase.Hexadecimal, tk.GetBase())
        Assert.Equal(&H1, tk.Value)
        Assert.Equal(" &H_1 ", tk.ToFullString())

        Str = " &B_1 "
        tk = ScanOnce(Str)
        Assert.Equal(SyntaxKind.IntegerLiteralToken, tk.Kind)
        Assert.Equal(LiteralBase.Binary, tk.GetBase())
        Assert.Equal(&B1, tk.Value)
        Assert.Equal(" &B_1 ", tk.ToFullString())

        Str = " &O_1 "
        tk = ScanOnce(Str)
        Assert.Equal(SyntaxKind.IntegerLiteralToken, tk.Kind)
        Assert.Equal(LiteralBase.Octal, tk.GetBase())
        Assert.Equal(&O1, tk.Value)
        Assert.Equal(" &O_1 ", tk.ToFullString())

        Str = " &H__1_1L "
        tk = ScanOnce(Str)
        Assert.Equal(SyntaxKind.IntegerLiteralToken, tk.Kind)
        Assert.Equal(LiteralBase.Hexadecimal, tk.GetBase())
        Assert.Equal(&H11L, tk.Value)
        Assert.Equal(" &H__1_1L ", tk.ToFullString())

        Str = " &B__1_1L "
        tk = ScanOnce(Str)
        Assert.Equal(SyntaxKind.IntegerLiteralToken, tk.Kind)
        Assert.Equal(LiteralBase.Binary, tk.GetBase())
        Assert.Equal(&B11L, tk.Value)
        Assert.Equal(" &B__1_1L ", tk.ToFullString())

        Str = " &O__1_1L "
        tk = ScanOnce(Str)
        Assert.Equal(SyntaxKind.IntegerLiteralToken, tk.Kind)
        Assert.Equal(LiteralBase.Octal, tk.GetBase())
        Assert.Equal(&O11L, tk.Value)
        Assert.Equal(" &O__1_1L ", tk.ToFullString())

        Str = " &H42L &H42& "
        Dim tks = ScanAllCheckDw(Str)
        Assert.Equal(SyntaxKind.IntegerLiteralToken, tks(0).Kind)
        Assert.Equal(LiteralBase.Hexadecimal, tks(1).GetBase())
        Assert.Equal(&H42L, tks(1).Value)
        Assert.Equal(TypeCharacter.Long, tks(1).GetTypeCharacter())

        Str = " &B1010L "
        tk = ScanOnce(Str)
        Assert.Equal(SyntaxKind.IntegerLiteralToken, tk.Kind)
        Assert.Equal(LiteralBase.Binary, tk.GetBase())
        Assert.Equal(&HAL, tk.Value)
        Assert.Equal(" &B1010L ", tk.ToFullString())
        Assert.Equal(0, tk.Errors().Count)
        Str = " &B1_0_1_0L "
        tk = ScanOnce(Str)
        Assert.Equal(SyntaxKind.IntegerLiteralToken, tk.Kind)
        Assert.Equal(LiteralBase.Binary, tk.GetBase())
        Assert.Equal(&HAL, tk.Value)
        Assert.Equal(" &B1_0_1_0L ", tk.ToFullString())
        Assert.Equal(0, tk.Errors().Count)
    End Sub

    <Fact>
    Public Sub Scanner_FloatingLiteralToken()
        Dim Str = "4.2"
        Dim tk = ScanOnce(Str)
        Assert.Equal(SyntaxKind.FloatingLiteralToken, tk.Kind)
        Assert.Equal(4.2, tk.Value)

        Str = " 0.42 "
        tk = ScanOnce(Str)
        Assert.Equal(SyntaxKind.FloatingLiteralToken, tk.Kind)
        Assert.Equal(0.42, tk.Value)
        Assert.IsType(Of Double)(tk.Value)
        Assert.Equal(" 0.42 ", tk.ToFullString())

        Str = " 0_0.4_2 "
        tk = ScanOnce(Str)
        Assert.Equal(SyntaxKind.FloatingLiteralToken, tk.Kind)
        Assert.Equal(0.42, tk.Value)
        Assert.IsType(Of Double)(tk.Value)
        Assert.Equal(" 0_0.4_2 ", tk.ToFullString())

        Str = " 0.42# "
        tk = ScanOnce(Str)
        Assert.Equal(SyntaxKind.FloatingLiteralToken, tk.Kind)
        Assert.Equal(0.42, tk.Value)
        Assert.IsType(Of Double)(tk.Value)
        Assert.Equal(" 0.42# ", tk.ToFullString())

        Str = " 0.42R "
        tk = ScanOnce(Str)
        Assert.Equal(SyntaxKind.FloatingLiteralToken, tk.Kind)
        Assert.Equal(0.42, tk.Value)
        Assert.IsType(Of Double)(tk.Value)
        Assert.Equal(" 0.42R ", tk.ToFullString())

        Str = " 0.42! "
        tk = ScanOnce(Str)
        Assert.Equal(SyntaxKind.FloatingLiteralToken, tk.Kind)
        Assert.Equal(0.42!, tk.Value)
        Assert.IsType(Of Single)(tk.Value)
        Assert.Equal(" 0.42! ", tk.ToFullString())

        Str = " 0.42F "
        tk = ScanOnce(Str)
        Assert.Equal(SyntaxKind.FloatingLiteralToken, tk.Kind)
        Assert.Equal(0.42F, tk.Value)
        Assert.IsType(Of Single)(tk.Value)
        Assert.Equal(" 0.42F ", tk.ToFullString())

        Str = " .42 42# "
        Dim tks = ScanAllCheckDw(Str)
        Assert.Equal(SyntaxKind.FloatingLiteralToken, tks(1).Kind)
        Assert.Equal(42.0#, tks(1).Value)
        Assert.Equal(0.42, tks(0).Value)
        Assert.IsType(Of Double)(tks(1).Value)
        Assert.Equal(TypeCharacter.Double, tks(1).GetTypeCharacter())
    End Sub

    <Fact>
    Public Sub Scanner_DecimalLiteralToken()
        Dim Str = "4.2D"
        Dim tk = ScanOnce(Str)
        Assert.Equal(SyntaxKind.DecimalLiteralToken, tk.Kind)
        Assert.Equal(TypeCharacter.DecimalLiteral, tk.GetTypeCharacter())
        Assert.Equal(4.2D, tk.Value)

        Str = " 0.42@ "
        tk = ScanOnce(Str)
        Assert.Equal(SyntaxKind.DecimalLiteralToken, tk.Kind)
        Assert.Equal(0.42@, tk.Value)
        Assert.Equal(" 0.42@ ", tk.ToFullString())

        Str = " .42D 4242424242424242424242424242@ "
        Dim tks = ScanAllCheckDw(Str)
        Assert.Equal(SyntaxKind.DecimalLiteralToken, tks(1).Kind)
        Assert.Equal(4242424242424242424242424242D, tks(1).Value)
        Assert.Equal(0.42D, tks(0).Value)
        Assert.Equal(TypeCharacter.Decimal, tks(1).GetTypeCharacter())
    End Sub

    <WorkItem(538543, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/538543")>
    <Fact>
    Public Sub Scanner_DecimalLiteralExpToken()
        Dim Str = "1E1D"
        Dim tk = ScanOnce(Str)
        Assert.Equal(SyntaxKind.DecimalLiteralToken, tk.Kind)
        Assert.Equal(TypeCharacter.DecimalLiteral, tk.GetTypeCharacter())
        Assert.Equal(10D, tk.Value)
    End Sub

    <Fact>
    Public Sub Scanner_Overflow()

        Dim Str = "2147483647I"
        Dim tk = ScanOnce(Str)
        Assert.Equal(SyntaxKind.IntegerLiteralToken, tk.Kind)
        Assert.Equal(2147483647I, CInt(tk.Value))

        Str = "2147483648I"
        tk = ScanOnce(Str)
        Assert.Equal(SyntaxKind.IntegerLiteralToken, tk.Kind)
        Assert.Equal(30036, tk.GetSyntaxErrorsNoTree()(0).Code)
        Assert.Equal(0, CInt(tk.Value))

        Str = "&H7FFFFFFFI"
        tk = ScanOnce(Str)
        Assert.Equal(SyntaxKind.IntegerLiteralToken, tk.Kind)
        Assert.Equal(&H7FFFFFFFI, CInt(tk.Value))

        Str = "&HFFFFFFFFI"
        tk = ScanOnce(Str)
        Assert.Equal(SyntaxKind.IntegerLiteralToken, tk.Kind)
        Assert.Equal(&HFFFFFFFFI, tk.Value)

        Str = "&HFFFFFFFFS"
        tk = ScanOnce(Str)
        Assert.Equal(SyntaxKind.IntegerLiteralToken, tk.Kind)
        Assert.Equal(30036, tk.GetSyntaxErrorsNoTree()(0).Code)
        Assert.Equal(0, CInt(tk.Value))

        Str = "&B111111111111111111111111111111111I"
        tk = ScanOnce(Str)
        Assert.Equal(SyntaxKind.IntegerLiteralToken, tk.Kind)
        Assert.Equal(30036, tk.GetSyntaxErrorsNoTree()(0).Code)
        Assert.Equal(0, CInt(tk.Value))

        Str = "&B11111111111111111111111111111111UI"
        tk = ScanOnce(Str)
        Assert.Equal(SyntaxKind.IntegerLiteralToken, tk.Kind)
        Assert.Equal(&HFFFFFFFFUI, CUInt(tk.Value))

        Str = "&B1111111111111111111111111111111I"
        tk = ScanOnce(Str)
        Assert.Equal(SyntaxKind.IntegerLiteralToken, tk.Kind)
        Assert.Equal(&H7FFFFFFFI, CInt(tk.Value))

        Str = "1.7976931348623157E+308d"
        tk = ScanOnce(Str)
        Assert.Equal(SyntaxKind.DecimalLiteralToken, tk.Kind)
        Assert.Equal(30036, tk.GetSyntaxErrorsNoTree()(0).Code)
        Assert.Equal(0D, tk.Value)

        Str = "1.797693134862315456489789797987987897897987987E+308F"
        tk = ScanOnce(Str)
        Assert.Equal(SyntaxKind.FloatingLiteralToken, tk.Kind)
        Assert.Equal(30036, tk.GetSyntaxErrorsNoTree()(0).Code)
        Assert.Equal(0.0F, tk.Value)
    End Sub

    <Fact>
    Public Sub Scanner_UnderscoreWrongLocation()
        Dim Str = "_1"
        Dim tk = ScanOnce(Str)
        Assert.Equal(SyntaxKind.IdentifierToken, tk.Kind)
        Assert.Equal(0, tk.GetSyntaxErrorsNoTree().Count())

        Str = "1_"
        tk = ScanOnce(Str)
        Assert.Equal(SyntaxKind.IntegerLiteralToken, tk.Kind)
        Assert.Equal(30035, tk.GetSyntaxErrorsNoTree()(0).Code)
        Assert.Equal(0, CInt(tk.Value))

        Str = "&H1_"
        tk = ScanOnce(Str)
        Assert.Equal(SyntaxKind.IntegerLiteralToken, tk.Kind)
        Assert.Equal(30035, tk.GetSyntaxErrorsNoTree()(0).Code)
        Assert.Equal(0, CInt(tk.Value))

        Str = "1_.1"
        tk = ScanOnce(Str)
        Assert.Equal(SyntaxKind.FloatingLiteralToken, tk.Kind)
        Assert.Equal(30035, tk.GetSyntaxErrorsNoTree()(0).Code)
        Assert.Equal(0, CInt(tk.Value))

        Str = "1.1_"
        tk = ScanOnce(Str)
        Assert.Equal(SyntaxKind.FloatingLiteralToken, tk.Kind)
        Assert.Equal(30035, tk.GetSyntaxErrorsNoTree()(0).Code)
        Assert.Equal(0, CInt(tk.Value))

        Str = "&H_"
        tk = ScanOnce(Str)
        Assert.Equal(SyntaxKind.IntegerLiteralToken, tk.Kind)
        Dim errors = tk.Errors()
        Assert.Equal(1, errors.Count)
        Assert.Equal(30035, errors.First().Code)
        Assert.Equal(0, CInt(tk.Value))

        Str = "&H_2_"
        tk = ScanOnce(Str)
        Assert.Equal(SyntaxKind.IntegerLiteralToken, tk.Kind)
        errors = tk.Errors()
        Assert.Equal(1, errors.Count)
        Assert.Equal(30035, errors.First().Code)
        Assert.Equal(0, CInt(tk.Value))
    End Sub

    <Fact>
    Public Sub Scanner_UnderscoreFeatureFlag()
        Dim Str = "&H_1"
        Dim tk = ScanOnce(Str, LanguageVersion.VisualBasic14)
        Assert.Equal(SyntaxKind.IntegerLiteralToken, tk.Kind)
        Dim errors = tk.Errors()
        Assert.Equal(1, errors.Count)
        Assert.Equal(36716, errors.First().Code)
        Assert.Equal(1, CInt(tk.Value))

        Str = "&H_123_456_789_ABC_DEF_123"
        tk = ScanOnce(Str, LanguageVersion.VisualBasic14)
        Assert.Equal(SyntaxKind.IntegerLiteralToken, tk.Kind)
        errors = tk.Errors()
        Assert.Equal(2, errors.Count)
        Assert.Equal(30036, errors.ElementAt(0).Code)
        Assert.Equal(36716, errors.ElementAt(1).Code)
        Assert.Equal(0, CInt(tk.Value))
    End Sub

    <Fact>
    Public Sub Scanner_DateLiteralToken()
        Dim Str = "#10/10/2010#"
        Dim tk = ScanOnce(Str)
        Assert.Equal(SyntaxKind.DateLiteralToken, tk.Kind)
        Assert.Equal(#10/10/2010#, tk.Value)

        Str = "#10/10/1#"
        tk = ScanOnce(Str)
        Assert.Equal(SyntaxKind.DateLiteralToken, tk.Kind)
        Assert.Equal(#10/10/0001#, tk.Value)

        Str = "#10/10/101#"
        tk = ScanOnce(Str)
        Assert.Equal(SyntaxKind.DateLiteralToken, tk.Kind)
        Assert.Equal(#10/10/0101#, tk.Value)

        Str = "#10/10/0#"
        tk = ScanOnce(Str)
        Assert.Equal(SyntaxKind.BadToken, tk.Kind)
        Assert.Equal(31085, tk.GetSyntaxErrorsNoTree()(0).Code)
        Assert.Equal("#10/10/0#", tk.ToFullString())

        Str = " #10/10/2010 10:10:00 PM# "
        tk = ScanOnce(Str)
        Assert.Equal(SyntaxKind.DateLiteralToken, tk.Kind)
        Assert.Equal(#10/10/2010 10:10:00 PM#, tk.Value)

        Str = "x = #10/10/2010##10/10/2010 10:10:00 PM# "
        Dim tks = ScanAllCheckDw(Str)
        Assert.Equal(#10/10/2010#, tks(2).Value)
        Assert.Equal(#10/10/2010 10:10:00 PM#, tks(3).Value)
    End Sub

    <Fact>
    Public Sub Scanner_DateLiteralTokenWithYearFirst()
        Dim text = "#1984-10-12#"
        Dim token = ScanOnce(text)
        Assert.Equal(SyntaxKind.DateLiteralToken, token.Kind)
        Assert.Equal(#10/12/1984#, token.Value)

        ' May use slash as separator in dates.
        text = "#1984/10/12#"
        token = ScanOnce(text)
        Assert.Equal(SyntaxKind.DateLiteralToken, token.Kind)
        Assert.Equal(#10/12/1984#, token.Value)

        ' Years must be four digits.
        text = "#84-10-12#"
        token = ScanOnce(text)
        Assert.Equal(SyntaxKind.BadToken, token.Kind)
        Assert.Equal(31085, token.GetSyntaxErrorsNoTree()(0).Code)

        text = "#84/10/12#"
        token = ScanOnce(text)
        Assert.Equal(SyntaxKind.BadToken, token.Kind)
        Assert.Equal(31085, token.GetSyntaxErrorsNoTree()(0).Code)

        ' Months may be one digit.
        text = "#2010-4-12#"
        token = ScanOnce(text)
        Assert.Equal(SyntaxKind.DateLiteralToken, token.Kind)
        Assert.Equal(#4/12/2010#, token.Value)

        ' Days may be one digit.
        text = "#1955/11/5#"
        token = ScanOnce(text)
        Assert.Equal(SyntaxKind.DateLiteralToken, token.Kind)
        Assert.Equal(#11/5/1955#, token.Value)

        ' Time only.
        text = " #09:45:01# "
        token = ScanOnce(text)
        Assert.Equal(SyntaxKind.DateLiteralToken, token.Kind)
        Assert.Equal(#1/1/1 9:45:01 AM#, token.Value)

        ' Date and time.
        text = " #   2010-04-12    9:00   # "
        token = ScanOnce(text)
        Assert.Equal(SyntaxKind.DateLiteralToken, token.Kind)
        Assert.Equal(#4/12/2010 9:00:00 AM#, token.Value)

        text = " #2010/04/12 9:00# "
        token = ScanOnce(text)
        Assert.Equal(SyntaxKind.DateLiteralToken, token.Kind)
        Assert.Equal(#4/12/2010 9:00:00 AM#, token.Value)

        text = "x = #2010-04-12##2010-04-12 09:00:00 # "
        Dim tokens = ScanAllCheckDw(text)
        Assert.Equal(#4/12/2010#, tokens(2).Value)
        Assert.Equal(#4/12/2010 9:00:00 AM#, tokens(3).Value)

        text = "#01984/10/12#"
        token = ScanOnce(text)
        Assert.Equal(SyntaxKind.BadToken, token.Kind)
        Assert.Equal(31085, token.GetSyntaxErrorsNoTree()(0).Code)

        text = "#984/10/12#"
        token = ScanOnce(text)
        Assert.Equal(SyntaxKind.BadToken, token.Kind)
        Assert.Equal(31085, token.GetSyntaxErrorsNoTree()(0).Code)

        text = "#1984/10/#"
        token = ScanOnce(text)
        Assert.Equal(SyntaxKind.BadToken, token.Kind)
        Assert.Equal(31085, token.GetSyntaxErrorsNoTree()(0).Code)

        text = "#1984//12#"
        token = ScanOnce(text)
        Assert.Equal(SyntaxKind.BadToken, token.Kind)
        Assert.Equal(31085, token.GetSyntaxErrorsNoTree()(0).Code)

        text = "#1984/10-12#"
        token = ScanOnce(text)
        Assert.Equal(SyntaxKind.BadToken, token.Kind)
        Assert.Equal(31085, token.GetSyntaxErrorsNoTree()(0).Code)

        text = "#1984-10/12#"
        token = ScanOnce(text)
        Assert.Equal(SyntaxKind.BadToken, token.Kind)
        Assert.Equal(31085, token.GetSyntaxErrorsNoTree()(0).Code)
    End Sub

    <Fact, WorkItem(529782, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/529782")>
    Public Sub DateAndDecimalCultureIndependentTokens()
        Dim SavedCultureInfo = CurrentThread.CurrentCulture
        Try
            CurrentThread.CurrentCulture = New System.Globalization.CultureInfo("de-DE", False)

            Dim Str = "4.2"
            Dim tk = ScanOnce(Str)
            Assert.Equal(SyntaxKind.FloatingLiteralToken, tk.Kind)
            Assert.Equal(4.2, tk.Value)

            Str = "4.2F"
            tk = ScanOnce(Str)
            Assert.Equal(SyntaxKind.FloatingLiteralToken, tk.Kind)
            Assert.Equal(4.2F, tk.Value)
            Assert.IsType(Of Single)(tk.Value)

            Str = "4.2R"
            tk = ScanOnce(Str)
            Assert.Equal(SyntaxKind.FloatingLiteralToken, tk.Kind)
            Assert.Equal(4.2R, tk.Value)
            Assert.IsType(Of Double)(tk.Value)

            Str = "4.2D"
            tk = ScanOnce(Str)
            Assert.Equal(SyntaxKind.DecimalLiteralToken, tk.Kind)
            Assert.Equal(4.2D, tk.Value)
            Assert.IsType(Of Decimal)(tk.Value)

            Str = "#8/23/1970 3:35:39AM#"
            tk = ScanOnce(Str)
            Assert.Equal(SyntaxKind.DateLiteralToken, tk.Kind)
            Assert.Equal(#8/23/1970 3:35:39 AM#, tk.Value)
        Finally
            CurrentThread.CurrentCulture = SavedCultureInfo
        End Try
    End Sub

    <Fact>
    Public Sub Scanner_BracketedIdentToken()
        Dim Str = "[Goo123]"
        Dim tk = ScanOnce(Str)
        Assert.Equal(SyntaxKind.IdentifierToken, tk.Kind)
        Assert.True(tk.IsBracketed)
        Assert.Equal("Goo123", tk.ValueText)
        Assert.Equal("Goo123", tk.Value)
        Assert.Equal("[Goo123]", tk.ToFullString())

        Str = "[__]"
        tk = ScanOnce(Str)
        Assert.Equal(SyntaxKind.IdentifierToken, tk.Kind)
        Assert.True(tk.IsBracketed)
        Assert.Equal("__", tk.ValueText)
        Assert.Equal("[__]", tk.ToFullString())

        Str = "[Goo ]"
        tk = ScanOnce(Str)
        Assert.Equal(SyntaxKind.BadToken, tk.Kind)
        Assert.Equal(30034, tk.GetSyntaxErrorsNoTree()(0).Code)
        Assert.Equal("[Goo ", tk.ToFullString())

        Str = "[]"
        tk = ScanOnce(Str)
        Assert.Equal(SyntaxKind.BadToken, tk.Kind)
        Assert.Equal(30203, tk.GetSyntaxErrorsNoTree()(0).Code)
        Assert.Equal("[]", tk.ToFullString())

        Str = "[_]"
        tk = ScanOnce(Str)
        Assert.Equal(SyntaxKind.BadToken, tk.Kind)
        Assert.Equal(30203, tk.GetSyntaxErrorsNoTree()(0).Code)
        Assert.Equal("[_]", tk.ToFullString())
    End Sub

    <Fact>
    Public Sub Scanner_StringLiteralValueText()
        Dim str = """Hello, World!"""

        Dim tk = ScanOnce(str)

        Assert.Equal(SyntaxKind.StringLiteralToken, tk.Kind)
        Assert.Equal("Hello, World!", tk.ValueText)
        Assert.Equal("""Hello, World!""", tk.ToFullString())
    End Sub

    <Fact>
    Public Sub Scanner_MultiLineStringLiteral()
        Dim text =
<text>"Hello,
World!"</text>.Value

        Dim token = ScanOnce(text)

        Assert.Equal(SyntaxKind.StringLiteralToken, token.Kind)
        Assert.Equal("Hello," & vbLf & "World!", token.ValueText)
        Assert.Equal("""Hello," & vbLf & "World!""", token.ToString())
    End Sub

    Private Function Repeat(str As String, num As Integer) As String
        Dim arr(num - 1) As String
        For i As Integer = 0 To num - 1
            arr(i) = str
        Next
        Return String.Join("", arr)
    End Function

    <Fact>
    Public Sub Scanner_BufferTest()
        For i As Integer = 0 To 12
            Dim TokenStr = New String("+"c, i)
            Dim tks = ScanAllCheckDw(TokenStr)
            Assert.Equal(i + 1, tks.Count)

            TokenStr = Repeat(" SomeIdentifier        ", i)
            tks = ScanAllCheckDw(TokenStr)
            Assert.Equal(i + 1, tks.Count)

            ' trying to place space after "someIdent" on ^2 boundary
            Dim identLen = Math.Max(1, CInt(2 ^ i) - 11)
            TokenStr = Repeat("X", identLen) & " someIdent " & Repeat("X", identLen + 11)
            tks = ScanAllNoDwCheck(TokenStr)
            Assert.Equal(4, tks.Count)
        Next

        For i As Integer = 100 To 5000 Step 250
            Dim TokenStr = New String("+"c, i)
            Dim tks = ScanAllCheckDw(TokenStr)
            Assert.Equal(i + 1, tks.Count)

            TokenStr = Repeat(" SomeIdentifier ", i)
            tks = ScanAllCheckDw(TokenStr)
            Assert.Equal(i + 1, tks.Count)
        Next
    End Sub

    <Fact>
    Public Sub Scanner_Bug866445()
        Dim x = &HFF00110001020408L
        Dim Str = "&HFF00110001020408L"
        Dim tk = ScanOnce(Str)
        Assert.Equal(SyntaxKind.IntegerLiteralToken, tk.Kind)
    End Sub

    <Fact>
    Public Sub Bug869260()
        Dim tk = ScanOnce(ChrW(0))
        Assert.Equal(SyntaxKind.BadToken, tk.Kind)
        Assert.Equal(CInt(ERRID.ERR_IllegalChar), tk.GetSyntaxErrorsNoTree(0).Code)
    End Sub

    <Fact>
    Public Sub Bug869081()
        ParseAndVerify(<![CDATA[
            <Obsolete()> _
        _
        _
        _
        _
            <CLSCompliant(False)> Class Class1
            End Class
        ]]>)
    End Sub

    <Fact>
    Public Sub Bug658441()
        ParseAndVerify(<![CDATA[
#If False Then
#If False Then
# _
#End If
# _
End If
#End If
        ]]>)
    End Sub

    <WorkItem(538747, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/538747")>
    <Fact>
    Public Sub OghamSpacemark()
        ParseAndVerify(<![CDATA[
Module M
End Module

        ]]>)
    End Sub

    <WorkItem(531175, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/531175")>
    <Fact>
    Public Sub Bug17703()
        ParseAndVerify(<![CDATA[
Dim x = <
”'

        ]]>,
                       <errors>
                           <error id="31151" message="Element is missing an end tag." start="9" end="23"/>
                           <error id="31146" message="XML name expected." start="10" end="10"/>
                           <error id="31146" message="XML name expected." start="10" end="10"/>
                           <error id="30249" message="'=' expected." start="10" end="10"/>
                           <error id="31164" message="Expected matching closing double quote for XML attribute value." start="23" end="23"/>
                           <error id="31165" message="Expected beginning &lt; for an XML tag." start="23" end="23"/>
                           <error id="30636" message="'>' expected." start="23" end="23"/>
                       </errors>)
    End Sub

    <WorkItem(530916, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/530916")>
    <Fact>
    Public Sub Bug17189()
        ParseAndVerify(<![CDATA[
a<
-'
-
        ]]>,
        <errors>
            <error id="30689" message="Statement cannot appear outside of a method body." start="1" end="17"/>
            <error id="30800" message="Method arguments must be enclosed in parentheses." start="2" end="17"/>
            <error id="31151" message="Element is missing an end tag." start="2" end="17"/>
            <error id="31177" message="White space cannot appear here." start="3" end="4"/>
            <error id="31169" message="Character '-' (&amp;H2D) is not allowed at the beginning of an XML name." start="4" end="5"/>
            <error id="31146" message="XML name expected." start="5" end="5"/>
            <error id="30249" message="'=' expected." start="5" end="5"/>
            <error id="31163" message="Expected matching closing single quote for XML attribute value." start="17" end="17"/>
            <error id="31165" message="Expected beginning '&lt;' for an XML tag." start="17" end="17"/>
            <error id="30636" message="'>' expected." start="17" end="17"/>
        </errors>)
    End Sub

    <WorkItem(530682, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/530682")>
    <Fact>
    Public Sub Bug16698()
        ParseAndVerify(<![CDATA[#Const x = <!--
]]>,
                    Diagnostic(ERRID.ERR_BadCCExpression, "<!--"))
    End Sub

    <WorkItem(865832, "DevDiv/Personal")>
    <Fact>
    Public Sub ParseSpecialKeywords()
        ParseAndVerify(<![CDATA[
            Module M1
                Dim x As Integer
                Sub Main
                    If True
                    End If
                End Sub
            End Module
        ]]>).
        VerifyNoWhitespaceInKeywords()
    End Sub

    <WorkItem(547317, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/547317")>
    <Fact>
    Public Sub ParseHugeNumber()
        ParseAndVerify(<![CDATA[
Module M
    Sub Main
 Dim x = CompareDouble(-7.92281625142643E337593543950335D)
    End Sub
EndModule


        ]]>,
        <errors>
            <error id="30625" message="'Module' statement must end with a matching 'End Module'." start="1" end="9"/>
            <error id="30036" message="Overflow." start="52" end="85"/>
            <error id="30188" message="Declaration expected." start="100" end="109"/>
        </errors>).
        VerifyNoWhitespaceInKeywords()
    End Sub

    <WorkItem(547317, "http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/547317")>
    <Fact>
    Public Sub ParseHugeNumberLabel()
        ParseAndVerify(<![CDATA[
Module M
    Sub Main

678901234567890123456789012345678901234567456789012345678901234567890123456789012345
    End Sub
EndModule

        ]]>,
        <errors>
            <error id="30625" message="'Module' statement must end with a matching 'End Module'." start="1" end="9"/>
            <error id="30801" message="Labels that are numbers must be followed by colons." start="30" end="114"/>
            <error id="30036" message="Overflow." start="30" end="114"/>
            <error id="30188" message="Declaration expected." start="128" end="137"/>
        </errors>).
        VerifyNoWhitespaceInKeywords()
    End Sub

    <WorkItem(926612, "DevDiv/Personal")>
    <Fact>
    Public Sub ScanMultilinesTriviaWithCRLFs()
        ParseAndVerify(<![CDATA[Option Compare Text

Public Class Assembly001bDll
    Sub main()
        Dim Asb As System.Reflection.Assembly
        Asb = System.Reflection.Assembly.GetExecutingAssembly()






        apcompare(Left(CurDir(), 1) & ":\School\assembly001bdll.dll", Asb.Location, "location")

    End Sub
End Class]]>)
    End Sub

    <Fact>
    Public Sub IsWhiteSpace()
        Assert.False(SyntaxFacts.IsWhitespace("A"c))
        Assert.True(SyntaxFacts.IsWhitespace(" "c))
        Assert.True(SyntaxFacts.IsWhitespace(ChrW(9)))
        Assert.False(SyntaxFacts.IsWhitespace(ChrW(0)))
        Assert.False(SyntaxFacts.IsWhitespace(ChrW(128)))
        Assert.False(SyntaxFacts.IsWhitespace(ChrW(129)))
        Assert.False(SyntaxFacts.IsWhitespace(ChrW(127)))
        Assert.True(SyntaxFacts.IsWhitespace(ChrW(160)))
        Assert.True(SyntaxFacts.IsWhitespace(ChrW(12288)))
        Assert.True(SyntaxFacts.IsWhitespace(ChrW(8192)))
        Assert.True(SyntaxFacts.IsWhitespace(ChrW(8203)))
    End Sub

    <Fact>
    Public Sub IsNewline()
        Assert.True(SyntaxFacts.IsNewLine(ChrW(13)))
        Assert.True(SyntaxFacts.IsNewLine(ChrW(10)))
        Assert.True(SyntaxFacts.IsNewLine(ChrW(133)))
        Assert.True(SyntaxFacts.IsNewLine(ChrW(8232)))
        Assert.True(SyntaxFacts.IsNewLine(ChrW(8233)))
        Assert.False(SyntaxFacts.IsNewLine(ChrW(132)))
        Assert.False(SyntaxFacts.IsNewLine(ChrW(160)))
        Assert.False(SyntaxFacts.IsNewLine(" "c))
        Assert.Equal(String.Empty, SyntaxFacts.MakeHalfWidthIdentifier(String.Empty))
        Assert.Null(SyntaxFacts.MakeHalfWidthIdentifier(Nothing))
        Assert.Equal("ABC", SyntaxFacts.MakeHalfWidthIdentifier("ABC"))
        Assert.Equal(ChrW(65280), SyntaxFacts.MakeHalfWidthIdentifier(ChrW(65280)))
        Assert.NotEqual(ChrW(65281), SyntaxFacts.MakeHalfWidthIdentifier(ChrW(65281)))
        Assert.Equal(1, SyntaxFacts.MakeHalfWidthIdentifier(ChrW(65281)).Length)
    End Sub

    <Fact>
    Public Sub MakeHalfWidthIdentifier()
        Assert.Equal(String.Empty, SyntaxFacts.MakeHalfWidthIdentifier(String.Empty))
        Assert.Equal(Nothing, SyntaxFacts.MakeHalfWidthIdentifier(Nothing))
        Assert.Equal("ABC", SyntaxFacts.MakeHalfWidthIdentifier("ABC"))
        Assert.Equal(ChrW(65280), SyntaxFacts.MakeHalfWidthIdentifier(ChrW(65280)))
        Assert.NotEqual(ChrW(65281), SyntaxFacts.MakeHalfWidthIdentifier(ChrW(65281)))
        Assert.Equal(1, SyntaxFacts.MakeHalfWidthIdentifier(ChrW(65281)).Length)
    End Sub
End Class

Module SyntaxDiagnosticInfoListExtensions
    <Extension>
    Public Function Count(list As SyntaxDiagnosticInfoList) As Integer
        Dim result = 0
        For Each v In list
            result += 1
        Next
        Return result
    End Function

    <Extension>
    Public Function First(list As SyntaxDiagnosticInfoList) As DiagnosticInfo
        For Each v In list
            Return v
        Next

        Throw New InvalidOperationException()
    End Function

    <Extension>
    Public Function ElementAt(list As SyntaxDiagnosticInfoList, index As Integer) As DiagnosticInfo
        Dim i = 0
        For Each v In list
            If i = index Then
                Return v
            End If
            i += 1
        Next

        Throw New IndexOutOfRangeException()
    End Function
End Module