private Diagnostic AnalyzeVariableDeclaration(VariableDeclarationSyntax declaration, ISymbol containingSymbol, SemanticModel semanticModel)
{
var type = declaration.GetTypeSymbol(semanticModel) as INamedTypeSymbol;
if (type is null)
{
return(null); // ignore unknown type
}
var identifier = declaration.Variables.Select(_ => _.Identifier).FirstOrDefault();
var eventName = identifier.ValueText;
if (eventName == nameof(ICommand.CanExecuteChanged) && type.Name == nameof(EventHandler))
{
return(null); // ignore event that we cannot change anymore
}
// we either nave no correct event handler or too few/less type arguments, so try to guess the EventArgs
if (type.TypeArguments.Length != 1)
{
return(null);
}
var eventArgsType = type.TypeArguments[0];
if (eventArgsType.IsEventArgs() is false)
{
return(null);
}
if (IsInherited(identifier, semanticModel))
{
return(null); // ignore inherited events that we cannot change anymore
}
if (eventArgsType.FullyQualifiedName() == "System.EventArgs")
{
return(null); // ignore special event args
}
var eventTypeNamespace = eventArgsType.ContainingNamespace.FullyQualifiedName();
var eventUsageNamespace = containingSymbol.ContainingNamespace.FullyQualifiedName();
if (eventUsageNamespace == eventTypeNamespace)
{
return(null); // ignore same namespaces
}
if (declaration.Type is GenericNameSyntax g)
{
return(Issue(eventName, g.TypeArgumentList.Arguments[0], eventArgsType.Name, eventUsageNamespace));
}
return(Issue(eventName, eventArgsType, eventArgsType.Name, eventUsageNamespace));
}
private Diagnostic AnalyzeVariableDeclaration(VariableDeclarationSyntax declaration, SemanticModel semanticModel)
{
var type = declaration.GetTypeSymbol(semanticModel) as INamedTypeSymbol;
var typeName = type?.Name;
if (typeName is null)
{
return(null); // ignore unknown type
}
var identifier = declaration.Variables.Select(_ => _.Identifier).FirstOrDefault();
var eventName = identifier.ValueText;
if (eventName == nameof(ICommand.CanExecuteChanged) && typeName == nameof(EventHandler))
{
return(null); // ignore event that we cannot change anymore
}
// we either nave no correct event handler or too few/less type arguments, so try to guess the EventArgs
var eventArgsType = type.TypeArguments.Length == 1 ? type.TypeArguments[0] : null;
var expectedName = eventName + nameof(EventArgs);
if (IsProperlyNamed(eventArgsType, expectedName))
{
return(null);
}
if (IsInherited(identifier, semanticModel))
{
return(null); // ignore inherited events that we cannot change anymore
}
return(Issue(typeName, declaration.Type, expectedName));
}