private static async Task <Document> FormatSummaryOnMultipleLinesAsync(
Document document,
DocumentationCommentTriviaSyntax documentationComment,
CancellationToken cancellationToken)
{
SourceText sourceText = await document.GetTextAsync(cancellationToken).ConfigureAwait(false);
XmlElementSyntax summaryElement = documentationComment.SummaryElement();
string indentation = "";
SyntaxTrivia parentTrivia = documentationComment.ParentTrivia;
SyntaxToken token = parentTrivia.Token;
SyntaxTriviaList leadingTrivia = token.LeadingTrivia;
int index = leadingTrivia.IndexOf(parentTrivia);
if (index > 0)
{
SyntaxTrivia previousTrivia = token.LeadingTrivia[index - 1];
if (previousTrivia.IsWhitespaceTrivia())
{
indentation = previousTrivia.ToString();
}
}
string endOfLine = documentationComment.DescendantTokens().FirstOrDefault(f => f.IsKind(SyntaxKind.XmlTextLiteralNewLineToken)).ToString();
if (endOfLine.Length == 0)
{
endOfLine = Environment.NewLine;
}
string startOfLine = endOfLine + indentation + "/// ";
SourceText newSourceText = sourceText.WithChanges(
new TextChange(new TextSpan(summaryElement.StartTag.Span.End, 0), startOfLine),
new TextChange(new TextSpan(summaryElement.EndTag.SpanStart, 0), startOfLine));
return(document.WithText(newSourceText));
}
private static string GetInteriorLinePrefix(DocumentationCommentTriviaSyntax node)
{
switch (node.Kind())
{
case SyntaxKind.SingleLineDocumentationCommentTrivia:
{
var firstToken = node.GetFirstToken();
char firstChar;
if (!TryGetFirstChar(firstToken, out firstChar))
{
return(string.Empty);
}
if (!IsWhitespace(firstChar))
{
return(string.Empty);
}
// Check for a matching whitespace character on every line.
foreach (var token in node.DescendantTokens())
{
if (token.Kind() == SyntaxKind.XmlTextLiteralNewLineToken)
{
var nextToken = token.GetNextToken();
// If the next token is beyond the end of the comment then the new
// line was the end of the comment.
if (!node.Span.Contains(nextToken.Span))
{
break;
}
if (!TryGetFirstChar(nextToken, out char c) || c != firstChar)
{
return(string.Empty);
}
}
}
return(firstChar.ToString(System.Globalization.CultureInfo.InvariantCulture));
}
case SyntaxKind.MultiLineDocumentationCommentTrivia:
{
string whitespace = null;
// Check for a matching whitespace prefix on every line after the first.
foreach (var token in node.DescendantTokens())
{
if (token.Kind() == SyntaxKind.XmlTextLiteralNewLineToken)
{
var nextToken = token.GetNextToken();
// If the next token is beyond the end of the comment then the new
// line was the end of the comment.
if (!node.Span.Contains(nextToken.Span))
{
break;
}
string text;
if (!TryGetLiteralText(nextToken, out text))
{
return(string.Empty);
}
if (whitespace == null)
{
// The whitespace prefix is the leading whitespace of the text.
for (int i = 0; i < text.Length; ++i)
{
if (!IsWhitespace(text[i]))
{
text = text.Substring(0, i - 1);
}
}
whitespace = text;
}
else if (!text.StartsWith(whitespace, StringComparison.Ordinal))
{
// The new whitespace prefix is the common prefix of the text
// and the old whitespace prefix.
for (int i = 0; i < text.Length; ++i)
{
if (text[i] != whitespace[i])
{
text = text.Substring(0, i - 1);
}
}
whitespace = text;
}
}
}
return(whitespace ?? string.Empty);
}
default:
throw new InvalidOperationException("Unreachable.");
}
bool TryGetFirstChar(SyntaxToken token, out char c)
{
string text;
if (!TryGetLiteralText(token, out text) ||
text.Length < 1)
{
c = default;
return(false);
}
c = text[0];
return(true);
}
bool TryGetLiteralText(SyntaxToken token, out string text)
{
if (token.Kind() != SyntaxKind.XmlTextLiteralToken)
{
text = default;
return(false);
}
text = token.ToString();
return(true);
}
}