private static bool CanReplaceInterpolationWithStringLiteralInnerText(SeparatedSyntaxList <ArgumentSyntax> arguments, bool isVerbatim)
{
bool result = false;
for (int i = 1; i < arguments.Count; i++)
{
ExpressionSyntax expression = arguments[i].Expression;
StringLiteralExpressionInfo info = SyntaxInfo.StringLiteralExpressionInfo(expression);
if (info.Success)
{
if (isVerbatim == info.IsVerbatim &&
info.Expression.GetLeadingTrivia().IsEmptyOrWhitespace() &&
info.Expression.GetTrailingTrivia().IsEmptyOrWhitespace())
{
result = true;
}
else
{
return(false);
}
}
}
return(result);
}
public static void AnalyzeInterpolation(SyntaxNodeAnalysisContext context)
{
var interpolation = (InterpolationSyntax)context.Node;
if (interpolation.AlignmentClause != null)
{
return;
}
if (interpolation.FormatClause != null)
{
return;
}
StringLiteralExpressionInfo stringLiteralInfo = SyntaxInfo.StringLiteralExpressionInfo(interpolation.Expression);
if (!stringLiteralInfo.Success)
{
return;
}
if (!(interpolation.Parent is InterpolatedStringExpressionSyntax interpolatedString))
{
return;
}
if (interpolatedString.StringStartToken.ValueText.Contains("@") != stringLiteralInfo.IsVerbatim)
{
return;
}
DiagnosticHelpers.ReportDiagnostic(context, DiagnosticDescriptors.UnnecessaryInterpolation, interpolation);
}
public void Append(LiteralExpressionSyntax stringLiteral)
{
if (stringLiteral == null)
{
return;
}
if (!stringLiteral.IsKind(SyntaxKind.StringLiteralExpression))
{
throw new ArgumentException("", nameof(stringLiteral));
}
StringLiteralExpressionInfo literalInfo = SyntaxInfo.StringLiteralExpressionInfo(stringLiteral);
bool isVerbatim = literalInfo.IsVerbatim;
if (IsVerbatim == isVerbatim)
{
string text = literalInfo.Text;
int length = text.Length;
if (length == 0)
{
return;
}
int startIndex = StringBuilder.Length;
if (isVerbatim)
{
StringBuilder.Append(text, 2, length - 3);
}
else
{
StringBuilder.Append(text, 1, length - 2);
}
if (IsInterpolated)
{
StringBuilder.Replace("{", "{{", startIndex);
StringBuilder.Replace("}", "}}", startIndex);
}
}
else
{
Append(literalInfo.ValueText);
}
}
private static int GetStartIndex(StringLiteralExpressionInfo info, TextSpan span)
{
int spanStart = info.Expression.SpanStart;
int index = span.Start - spanStart;
string text = info.Text;
if (info.IsVerbatim)
{
if (index > 1 &&
StringLiteralParser.CanExtractSpan(text, 2, text.Length - 3, span.Offset(-spanStart), isVerbatim: true, isInterpolatedText: false))
{
return(index);
}
}
else if (index > 0 &&
StringLiteralParser.CanExtractSpan(text, 1, text.Length - 2, span.Offset(-spanStart), isVerbatim: false, isInterpolatedText: false))
{
return(index);
}
return(-1);
}
private static void AnalyzeAddExpression(SyntaxNodeAnalysisContext context)
{
SyntaxNode node = context.Node;
if (node.ContainsDiagnostics)
{
return;
}
if (node.SpanContainsDirectives())
{
return;
}
if (node.IsParentKind(SyntaxKind.AddExpression))
{
return;
}
var addExpression = (BinaryExpressionSyntax)node;
ExpressionSyntax firstExpression = null;
ExpressionSyntax lastExpression = null;
bool isLiteral = false;
bool isVerbatim = false;
foreach (ExpressionSyntax expression in addExpression.AsChain().Reverse())
{
context.CancellationToken.ThrowIfCancellationRequested();
switch (expression.Kind())
{
case SyntaxKind.StringLiteralExpression:
{
StringLiteralExpressionInfo stringLiteral = SyntaxInfo.StringLiteralExpressionInfo(expression);
bool isVerbatim2 = stringLiteral.IsVerbatim;
if (firstExpression == null)
{
firstExpression = expression;
isLiteral = true;
isVerbatim = isVerbatim2;
}
else if (!isLiteral ||
isVerbatim != isVerbatim2 ||
(!isVerbatim && !CheckHexadecimalEscapeSequence(stringLiteral)))
{
if (lastExpression != null)
{
Analyze(context, firstExpression, lastExpression, isVerbatim);
}
firstExpression = null;
lastExpression = null;
}
else
{
lastExpression = expression;
}
break;
}
case SyntaxKind.InterpolatedStringExpression:
{
var interpolatedString = ((InterpolatedStringExpressionSyntax)expression);
bool isVerbatim2 = interpolatedString.IsVerbatim();
if (firstExpression == null)
{
firstExpression = expression;
isLiteral = false;
isVerbatim = isVerbatim2;
}
else if (isLiteral ||
isVerbatim != isVerbatim2 ||
(!isVerbatim && !CheckHexadecimalEscapeSequence(interpolatedString)))
{
if (lastExpression != null)
{
Analyze(context, firstExpression, lastExpression, isVerbatim);
}
firstExpression = null;
lastExpression = null;
}
else
{
lastExpression = expression;
}
break;
}
default:
{
if (lastExpression != null)
{
Analyze(context, firstExpression, lastExpression, isVerbatim);
}
firstExpression = null;
lastExpression = null;
break;
}
}
}
if (lastExpression != null)
{
Analyze(context, firstExpression, lastExpression, isVerbatim);
}
}
private static InterpolatedStringExpressionSyntax ReplaceInterpolationWithStringLiteralInnerText(
SeparatedSyntaxList <ArgumentSyntax> arguments,
InterpolatedStringExpressionSyntax interpolatedString,
string text)
{
StringBuilder sb = StringBuilderCache.GetInstance();
int pos = 0;
SyntaxList <InterpolatedStringContentSyntax> contents = interpolatedString.Contents;
for (int i = 0; i < contents.Count; i++)
{
if (contents[i].Kind() != SyntaxKind.Interpolation)
{
continue;
}
var interpolation = (InterpolationSyntax)contents[i];
ExpressionSyntax expression = interpolation.Expression;
if (expression?.Kind() != SyntaxKind.NumericLiteralExpression)
{
continue;
}
var index = (int)((LiteralExpressionSyntax)expression).Token.Value;
if (index < 0)
{
continue;
}
if (index >= arguments.Count)
{
continue;
}
ExpressionSyntax argumentExpression = arguments[index + 1].Expression;
StringLiteralExpressionInfo stringLiteral = SyntaxInfo.StringLiteralExpressionInfo(argumentExpression);
if (!stringLiteral.Success)
{
continue;
}
sb.Append(text, pos, interpolation.SpanStart - pos);
int startIndex = sb.Length;
sb.Append(stringLiteral.InnerText);
sb.Replace("{", "{{", startIndex);
sb.Replace("}", "}}", startIndex);
pos = interpolation.Span.End;
}
sb.Append(text, pos, text.Length - pos);
return((InterpolatedStringExpressionSyntax)ParseExpression(StringBuilderCache.GetStringAndFree(sb)));
}
public static async Task ComputeRefactoringsAsync(RefactoringContext context, LiteralExpressionSyntax literalExpression)
{
StringLiteralExpressionInfo info = SyntaxInfo.StringLiteralExpressionInfo(literalExpression);
Debug.Assert(info.Success);
if (!info.Success)
{
return;
}
if (context.IsRefactoringEnabled(RefactoringIdentifiers.InsertStringInterpolation) &&
context.SupportsCSharp6 &&
context.Span.End < literalExpression.Span.End)
{
int startIndex = GetStartIndex(info, context.Span);
if (startIndex != -1)
{
context.RegisterRefactoring(
"Insert interpolation",
cancellationToken =>
{
return(ReplaceWithInterpolatedStringAsync(
context.Document,
literalExpression,
startIndex,
context.Span.Length,
addNameOf: false,
cancellationToken: cancellationToken));
});
if (!context.Span.IsEmpty)
{
SemanticModel semanticModel = await context.GetSemanticModelAsync().ConfigureAwait(false);
string name = StringLiteralParser.Parse(literalExpression.Token.Text, startIndex, context.Span.Length, info.IsVerbatim, isInterpolatedText: false);
foreach (ISymbol symbol in semanticModel.LookupSymbols(literalExpression.SpanStart))
{
if (string.Equals(name, symbol.MetadataName, StringComparison.Ordinal))
{
context.RegisterRefactoring(
"Insert interpolation with nameof",
cancellationToken =>
{
return(ReplaceWithInterpolatedStringAsync(
context.Document,
literalExpression,
startIndex,
context.Span.Length,
addNameOf: true,
cancellationToken: cancellationToken));
});
break;
}
}
}
}
}
if (context.Span.IsBetweenSpans(literalExpression))
{
if (info.IsVerbatim)
{
if (info.ContainsEscapeSequence)
{
if (context.IsRefactoringEnabled(RefactoringIdentifiers.ReplaceVerbatimStringLiteralWithRegularStringLiteral))
{
context.RegisterRefactoring(
"Replace verbatim string literal with regular string literal",
ct => ReplaceWithRegularStringLiteralAsync(context.Document, literalExpression, ct));
}
if (context.IsRefactoringEnabled(RefactoringIdentifiers.ReplaceVerbatimStringLiteralWithRegularStringLiterals) &&
info.ContainsLinefeed)
{
context.RegisterRefactoring(
"Replace verbatim string literal with regular string literals",
ct => ReplaceWithRegularStringLiteralsAsync(context.Document, literalExpression, ct));
}
}
}
else if (context.IsRefactoringEnabled(RefactoringIdentifiers.ReplaceRegularStringLiteralWithVerbatimStringLiteral) &&
info.ContainsEscapeSequence)
{
context.RegisterRefactoring(
"Replace regular string literal with verbatim string literal",
ct => ReplaceWithVerbatimStringLiteralAsync(context.Document, literalExpression, ct));
}
}
if (context.IsRefactoringEnabled(RefactoringIdentifiers.UseStringEmptyInsteadOfEmptyStringLiteral) &&
CanReplaceWithStringEmpty(literalExpression))
{
context.RegisterRefactoring(
"Replace \"\" with 'string.Empty'",
ct => ReplaceWithStringEmptyAsync(context.Document, literalExpression, ct));
}
}
