private static SubpatternSyntax?TrySimplify(SubpatternSyntax currentSubpattern)
{
if (!SimplifyPropertyPatternHelpers.IsSimplifiable(currentSubpattern, out var innerSubpattern, out var outerExpressionColon))
{
return(null);
}
// attempt to simplify the inner pattern we're pointing at as well (that way if the user
// invokes the fix on a top level property, we collapse as far inwards as possible).
innerSubpattern = TrySimplify(innerSubpattern) ?? innerSubpattern;
var innerExpressionColon = innerSubpattern.ExpressionColon;
if (!SimplifyPropertyPatternHelpers.IsMergable(outerExpressionColon.Expression) ||
!SimplifyPropertyPatternHelpers.IsMergable(innerExpressionColon?.Expression))
{
return(null);
}
var merged = Merge(outerExpressionColon, innerExpressionColon);
if (merged == null)
{
return(null);
}
return(currentSubpattern.WithExpressionColon(merged)
.WithPattern(innerSubpattern.Pattern)
.WithAdditionalAnnotations(Formatter.Annotation));
}
private void AnalyzeSubpattern(SyntaxNodeAnalysisContext syntaxContext)
{
// Bail immediately if the user has disabled this feature.
var styleOption = syntaxContext.GetCSharpAnalyzerOptions().PreferExtendedPropertyPattern;
if (!styleOption.Value)
{
return;
}
var severity = styleOption.Notification.Severity;
var subpattern = (SubpatternSyntax)syntaxContext.Node;
if (!SimplifyPropertyPatternHelpers.IsSimplifiable(subpattern, out _, out var expressionColon))
{
return;
}
// If the diagnostic is not hidden, then just place the user visible part
// on the local being initialized with the lambda.
syntaxContext.ReportDiagnostic(DiagnosticHelper.Create(
Descriptor,
expressionColon.GetLocation(),
severity,
ImmutableArray.Create(subpattern.GetLocation()),
properties: null));
}
