internal static void AnalyzeSyntaxTree(SyntaxTreeAnalysisContext context, FormattingProvider formattingProvider, DiagnosticDescriptor descriptor, SyntaxFormattingOptions options)
{
var tree = context.Tree;
var cancellationToken = context.CancellationToken;
var oldText = tree.GetText(cancellationToken);
var formattingChanges = Formatter.GetFormattedTextChanges(tree.GetRoot(cancellationToken), formattingProvider, options, cancellationToken);
// formattingChanges could include changes that impact a larger section of the original document than
// necessary. Before reporting diagnostics, process the changes to minimize the span of individual
// diagnostics.
foreach (var formattingChange in formattingChanges)
{
var change = formattingChange;
if (change.NewText.Length > 0 && !change.Span.IsEmpty)
{
// Handle cases where the change is a substring removal from the beginning. In these cases, we want
// the diagnostic span to cover the unwanted leading characters (which should be removed), and
// nothing more.
var offset = change.Span.Length - change.NewText.Length;
if (offset >= 0)
{
if (oldText.GetSubText(new TextSpan(change.Span.Start + offset, change.NewText.Length)).ContentEquals(SourceText.From(change.NewText)))
{
change = new TextChange(new TextSpan(change.Span.Start, offset), "");
}
else
{
// Handle cases where the change is a substring removal from the end. In these cases, we want
// the diagnostic span to cover the unwanted trailing characters (which should be removed), and
// nothing more.
if (oldText.GetSubText(new TextSpan(change.Span.Start, change.NewText.Length)).ContentEquals(SourceText.From(change.NewText)))
{
change = new TextChange(new TextSpan(change.Span.Start + change.NewText.Length, offset), "");
}
}
}
}
if (change.NewText.Length == 0 && change.Span.IsEmpty)
{
// No actual change (allows for the formatter to report a NOP change without triggering a
// diagnostic that can't be fixed).
continue;
}
var location = Location.Create(tree, change.Span);
context.ReportDiagnostic(Diagnostic.Create(
descriptor,
location,
additionalLocations: null,
properties: null));
}
}
internal static async Task <SyntaxTree> FixOneAsync(SyntaxTree syntaxTree, FormattingProvider formattingProvider, SyntaxFormattingOptions options, Diagnostic diagnostic, CancellationToken cancellationToken)
{
// The span to format is the full line(s) containing the diagnostic
var text = await syntaxTree.GetTextAsync(cancellationToken).ConfigureAwait(false);
var diagnosticSpan = diagnostic.Location.SourceSpan;
var diagnosticLinePositionSpan = text.Lines.GetLinePositionSpan(diagnosticSpan);
var spanToFormat = TextSpan.FromBounds(
text.Lines[diagnosticLinePositionSpan.Start.Line].Start,
text.Lines[diagnosticLinePositionSpan.End.Line].End);
var root = await syntaxTree.GetRootAsync(cancellationToken).ConfigureAwait(false);
var formattedRoot = Formatter.Format(root, spanToFormat, formattingProvider, options, cancellationToken);
return(syntaxTree.WithRootAndOptions(formattedRoot, syntaxTree.Options));
}
