private async Task <Document> InitializeFieldAsync(Document document, SyntaxNode root,
ParameterSyntax parameter, ConstructorDeclarationSyntax constructor,
CancellationToken cancellationToken)
{
string fieldName;
var typeDeclaration = constructor.GetParentTypeDeclaration();
var trackedRoot = root.TrackNodes(constructor, typeDeclaration);
var model = await document.GetSemanticModelAsync(cancellationToken);
var existingField = FindExistingField(model, parameter, constructor.Parent as TypeDeclarationSyntax, cancellationToken);
if (existingField != null)
{
fieldName = existingField.Name;
}
else
{
fieldName = await nameGenerator.GetNewMemberNameAsync(constructor.Parent as TypeDeclarationSyntax, parameter.Identifier.ValueText, document, cancellationToken);
var field = CreateFieldDeclaration(parameter.Type, fieldName);
var insertionPoint = FindInsertionPointBelowFieldGroup(trackedRoot.GetCurrentNode(typeDeclaration));
if (insertionPoint != null)
{
trackedRoot = trackedRoot.InsertNodesAfter(insertionPoint, SingletonList(field));
}
else
{
// skip parent/interface list, type parameter list, type parameter constraint list and attribute list
insertionPoint = trackedRoot.GetCurrentNode(typeDeclaration).ChildNodes()
.First(node =>
!(node is BaseListSyntax) &&
!(node is TypeParameterListSyntax) &&
!(node is TypeParameterConstraintClauseSyntax) &&
!(node is AttributeListSyntax));
trackedRoot = trackedRoot.InsertNodesBefore(insertionPoint, SingletonList(field));
}
}
var assignment = constructor.ParameterList.Parameters.Any(p => p.Identifier.ValueText == fieldName)
? CreateThisAssignmentStatement(fieldName, parameter.Identifier.ValueText)
: CreateAssignmentStatement(fieldName, parameter.Identifier.ValueText);
var constructorBody = trackedRoot.GetCurrentNode(constructor).Body;
var newConstructorBody = constructorBody.AddStatements(assignment)
.WithAdditionalAnnotations(Formatter.Annotation);
trackedRoot = trackedRoot.ReplaceNode(constructorBody, newConstructorBody);
return(document.WithSyntaxRoot(trackedRoot));
}