/// <summary>
/// Gets a value indicating whether the given trivia span multiple source text lines.
/// </summary>
/// <param name="trivia">The trivia to check.</param>
/// <returns>
/// <see langword="true"/> if the trivia spans multiple source text lines; otherwise, <see langword="false"/>.
/// </returns>
internal static bool SpansMultipleLines(this SyntaxTrivia trivia)
{
var lineSpan = trivia.GetLineSpan();
if (lineSpan == null)
{
return(false);
}
return(lineSpan.Value.StartLinePosition.Line < lineSpan.Value.EndLinePosition.Line);
}
private static async Task <Document> GetTransformedDocumentAsync(
Document document,
Diagnostic diagnostic,
CancellationToken cancellationToken)
{
SyntaxNode syntaxRoot = await document.GetSyntaxRootAsync(cancellationToken).ConfigureAwait(false);
// For DocumentationCommentExteriorTrivia we must use findInsideTrivia: true so we don't get the entire XML comment trivia.
SyntaxTrivia violatingTrivia = syntaxRoot.FindTrivia(diagnostic.Location.SourceSpan.Start, findInsideTrivia: true);
string originalIndent = violatingTrivia.ToFullString();
int tabSize = GetTabSize(document);
// If they've mixed tabs and spaces, then we need to figure out the original indent length in spaces.
int startColumn = violatingTrivia.GetLineSpan().StartLinePosition.Character;
int originalIndentColumn = startColumn;
string nonWhitespaceSuffix = null;
for (int i = 0; i < originalIndent.Length; i++)
{
char ch = originalIndent[i];
if (ch == '\t')
{
var offsetWithinTabColumn = originalIndentColumn % tabSize;
var spaceCount = tabSize - offsetWithinTabColumn;
originalIndentColumn += spaceCount;
}
else if (char.IsWhiteSpace(ch))
{
originalIndentColumn++;
}
else
{
// For DocumentationCommentExteriorTrivia we must keep the /// suffix.
nonWhitespaceSuffix = originalIndent.Substring(i);
break;
}
}
// We know that the violating trivia was leading whitespace trivia, and we NEVER want to use
// spaces for indentation. So even if the indentation size isn't a multiple of the tab size, we'll
// generate the new indentation string as only tabs.
int originalIndentSpaceLength = originalIndentColumn - startColumn;
int numTabs = originalIndentSpaceLength / tabSize;
string tabIndent = new string('\t', numTabs) + nonWhitespaceSuffix;
SyntaxTrivia newTrivia = violatingTrivia.IsKind(SyntaxKind.DocumentationCommentExteriorTrivia)
? SyntaxFactory.DocumentationCommentExterior(tabIndent)
: SyntaxFactory.Whitespace(tabIndent);
var newSyntaxRoot = syntaxRoot.ReplaceTrivia(violatingTrivia, newTrivia);
return(document.WithSyntaxRoot(newSyntaxRoot));
}
private static bool AcceptableSingleLineTrivia(SyntaxTrivia trivia)
{
switch (trivia.Kind())
{
case SyntaxKind.WhitespaceTrivia:
case SyntaxKind.EndOfLineTrivia:
return(true);
case SyntaxKind.MultiLineCommentTrivia:
var lineSpan = trivia.GetLineSpan();
return(lineSpan.StartLinePosition.Line == lineSpan.EndLinePosition.Line);
default:
return(false);
}
}
private static bool AcceptableSingleLineTrivia(SyntaxTrivia trivia)
{
switch (trivia.Kind())
{
case SyntaxKind.WhitespaceTrivia:
case SyntaxKind.EndOfLineTrivia:
return true;
case SyntaxKind.MultiLineCommentTrivia:
var lineSpan = trivia.GetLineSpan();
return lineSpan.StartLinePosition.Line == lineSpan.EndLinePosition.Line;
default:
return false;
}
}
private static void HandleWhitespaceTrivia(SyntaxTreeAnalysisContext context, SyntaxTrivia trivia)
{
// We can ignore structured trivia like directives (e.g., #region, #pragma) and XML comments.
if (!trivia.HasStructure)
{
// We only need to look at leading trivia. It's ok to use spaces between keywords (e.g., private void Method()),
// and those usually show up as trailing trivia. However, sometimes spaces between identifiers show up as leading
// trivia (e.g., in <param name="X">). So we have to make sure the leading trivia is really at the beginning of a line.
SyntaxToken token = trivia.Token;
if (token.LeadingTrivia.IndexOf(trivia) >= 0 &&
trivia.ToFullString().IndexOf(' ') >= 0 &&
trivia.GetLineSpan().StartLinePosition.Character == 0)
{
context.ReportDiagnostic(Diagnostic.Create(Rule, trivia.GetLocation()));
}
}
}
/// <summary>
/// Gets the line on which the given trivia occurs.
/// </summary>
/// <param name="trivia">The trivia to use.</param>
/// <returns>The line on which the given trivia occurs.</returns>
internal static int?GetLine(this SyntaxTrivia trivia)
{
return(trivia.GetLineSpan()?.StartLinePosition.Line);
}
/// <summary>
/// Gets a value indicating whether the given trivia span multiple source text lines.
/// </summary>
/// <param name="trivia">The trivia to check.</param>
/// <returns>
/// <see langword="true"/> if the trivia spans multiple source text lines; otherwise, <see langword="false"/>.
/// </returns>
internal static bool SpansMultipleLines(this SyntaxTrivia trivia)
{
var lineSpan = trivia.GetLineSpan();
return(lineSpan.StartLinePosition.Line < lineSpan.EndLinePosition.Line);
}
/// <summary>
/// Gets the end line of the given trivia.
/// </summary>
/// <param name="trivia">The trivia to use.</param>
/// <returns>The line on which the given trivia ends.</returns>
internal static int GetEndLine(this SyntaxTrivia trivia)
{
return(trivia.GetLineSpan().EndLinePosition.Line);
}
