private static async Task <CompletionChange> GetConversionChangeAsync(
Document document, CompletionItem item, CancellationToken cancellationToken)
{
var position = SymbolCompletionItem.GetContextPosition(item);
var text = await document.GetTextAsync(cancellationToken).ConfigureAwait(false);
var root = await document.GetRequiredSyntaxRootAsync(cancellationToken).ConfigureAwait(false);
var(dotToken, _) = GetDotAndExpressionStart(root, position, cancellationToken);
var questionToken = dotToken.GetPreviousToken().Kind() == SyntaxKind.QuestionToken
? dotToken.GetPreviousToken()
: (SyntaxToken?)null;
var expression = (ExpressionSyntax)dotToken.GetRequiredParent();
expression = expression.GetRootConditionalAccessExpression() ?? expression;
var replacement = questionToken != null
? $"(({item.DisplayText}){text.ToString(TextSpan.FromBounds(expression.SpanStart, questionToken.Value.FullSpan.Start))}){questionToken.Value}"
: $"(({item.DisplayText}){text.ToString(TextSpan.FromBounds(expression.SpanStart, dotToken.SpanStart))})";
// If we're at `x.$$.y` then we only want to replace up through the first dot.
var tokenOnLeft = root.FindTokenOnLeftOfPosition(position, includeSkipped: true);
var fullTextChange = new TextChange(
TextSpan.FromBounds(
expression.SpanStart,
tokenOnLeft.Kind() == SyntaxKind.DotDotToken ? tokenOnLeft.SpanStart + 1 : tokenOnLeft.Span.End),
replacement);
var newPosition = expression.SpanStart + replacement.Length;
return(CompletionChange.Create(fullTextChange, newPosition));
}
private static async Task <CompletionChange> GetConversionChangeAsync(
Document document, CompletionItem item, CancellationToken cancellationToken)
{
var position = SymbolCompletionItem.GetContextPosition(item);
var text = await document.GetTextAsync(cancellationToken).ConfigureAwait(false);
var root = await document.GetRequiredSyntaxRootAsync(cancellationToken).ConfigureAwait(false);
var(dotToken, _) = GetDotAndExpressionStart(root, position, cancellationToken);
var questionToken = dotToken.GetPreviousToken().Kind() == SyntaxKind.QuestionToken
? dotToken.GetPreviousToken()
: (SyntaxToken?)null;
var expression = (ExpressionSyntax)dotToken.GetRequiredParent();
expression = expression.GetRootConditionalAccessExpression() ?? expression;
using var _ = ArrayBuilder <TextChange> .GetInstance(out var builder);
// First, add the cast prior to the expression.
var castText = $"(({item.DisplayText})";
builder.Add(new TextChange(new TextSpan(expression.SpanStart, 0), castText));
// The expression went up to either a `.`, `..`, `?.` or `?..`
//
// In the case of `expr.` produce `((T)expr)$$`
//
// In the case of `expr..` produce ((T)expr)$$.
//
// In the case of `expr?.` produce `((T)expr)?$$`
if (questionToken == null)
{
// Always eat the first dot in `.` or `..` and replace that with the paren.
builder.Add(new TextChange(new TextSpan(dotToken.SpanStart, 1), ")"));
}
else
{
// Place a paren before the question.
builder.Add(new TextChange(new TextSpan(questionToken.Value.SpanStart, 0), ")"));
// then remove the first dot that comes after.
builder.Add(new TextChange(new TextSpan(dotToken.SpanStart, 1), ""));
}
// If the user partially wrote out the conversion type, delete what they've written.
var tokenOnLeft = root.FindTokenOnLeftOfPosition(position, includeSkipped: true);
if (CSharpSyntaxFacts.Instance.IsWord(tokenOnLeft))
{
builder.Add(new TextChange(tokenOnLeft.Span, ""));
}
var newText = text.WithChanges(builder);
var allChanges = builder.ToImmutable();
// Collapse all text changes down to a single change (for clients that only care about that), but also keep
// all the individual changes around for clients that prefer the fine-grained information.
return(CompletionChange.Create(
CodeAnalysis.Completion.Utilities.Collapse(newText, allChanges),
allChanges));
}