/// <inheritdoc />
public override async Task RegisterCodeFixesAsync(CodeFixContext context)
{
Diagnostic diagnostic = context.Diagnostics.First();
SyntaxNode root = await context.Document.GetSyntaxRootAsync(context.CancellationToken).ConfigureAwait(false);
BaseTypeSyntax baseTypeSyntax = root.FindNode(diagnostic.Location.SourceSpan).FirstAncestorOrSelf <BaseTypeSyntax>();
ClassDeclarationSyntax classDeclarationSyntax = baseTypeSyntax.FirstAncestorOrSelf <ClassDeclarationSyntax>();
context.RegisterCodeFix(
CodeAction.Create("Convert to async package", ct => this.ConvertToAsyncPackageAsync(context, diagnostic, ct), "only one"),
diagnostic);
}
private async Task <Document> ConvertToAsyncPackageAsync(CodeFixContext context, Diagnostic diagnostic, CancellationToken cancellationToken)
{
SemanticModel semanticModel = await context.Document.GetSemanticModelAsync(cancellationToken).ConfigureAwait(false);
Compilation?compilation = await context.Document.Project.GetCompilationAsync(cancellationToken).ConfigureAwait(false);
Assumes.NotNull(compilation);
SyntaxNode root = await context.Document.GetSyntaxRootAsync(cancellationToken).ConfigureAwait(false);
BaseTypeSyntax baseTypeSyntax = root.FindNode(diagnostic.Location.SourceSpan).FirstAncestorOrSelf <BaseTypeSyntax>();
ClassDeclarationSyntax classDeclarationSyntax = baseTypeSyntax.FirstAncestorOrSelf <ClassDeclarationSyntax>();
MethodDeclarationSyntax initializeMethodSyntax = classDeclarationSyntax.DescendantNodes()
.OfType <MethodDeclarationSyntax>()
.FirstOrDefault(method => method.Modifiers.Any(modifier => modifier.IsKind(SyntaxKind.OverrideKeyword)) && method.Identifier.Text == Types.Package.Initialize);
InvocationExpressionSyntax?baseInitializeInvocationSyntax = initializeMethodSyntax?.Body?.DescendantNodes()
.OfType <InvocationExpressionSyntax>()
.FirstOrDefault(ies => ies.Expression is MemberAccessExpressionSyntax memberAccess && memberAccess.Name?.Identifier.Text == Types.Package.Initialize && memberAccess.Expression is BaseExpressionSyntax);
var getServiceInvocationsSyntax = new List <InvocationExpressionSyntax>();
AttributeSyntax?packageRegistrationSyntax = null;
{
INamedTypeSymbol userClassSymbol = semanticModel.GetDeclaredSymbol(classDeclarationSyntax, context.CancellationToken);
INamedTypeSymbol packageRegistrationType = compilation.GetTypeByMetadataName(Types.PackageRegistrationAttribute.FullName);
AttributeData? packageRegistrationInstance = userClassSymbol?.GetAttributes().FirstOrDefault(a => Equals(a.AttributeClass, packageRegistrationType));
if (packageRegistrationInstance?.ApplicationSyntaxReference != null)
{
packageRegistrationSyntax = (AttributeSyntax)await packageRegistrationInstance.ApplicationSyntaxReference.GetSyntaxAsync(cancellationToken).ConfigureAwait(false);
}
}
if (initializeMethodSyntax != null)
{
getServiceInvocationsSyntax.AddRange(
from invocation in initializeMethodSyntax.DescendantNodes().OfType <InvocationExpressionSyntax>()
let memberBinding = invocation.Expression as MemberAccessExpressionSyntax
let identifierName = invocation.Expression as IdentifierNameSyntax
where identifierName?.Identifier.Text == Types.Package.GetService ||
(memberBinding.Name.Identifier.Text == Types.Package.GetService && memberBinding.Expression.IsKind(SyntaxKind.ThisExpression))
select invocation);
}
// Make it easier to track nodes across changes.
var nodesToTrack = new List <SyntaxNode?>
{
baseTypeSyntax,
initializeMethodSyntax,
baseInitializeInvocationSyntax,
packageRegistrationSyntax,
};
nodesToTrack.AddRange(getServiceInvocationsSyntax);
nodesToTrack.RemoveAll(n => n == null);
SyntaxNode updatedRoot = root.TrackNodes(nodesToTrack);
// Replace the Package base type with AsyncPackage
baseTypeSyntax = updatedRoot.GetCurrentNode(baseTypeSyntax);
SimpleBaseTypeSyntax asyncPackageBaseTypeSyntax = SyntaxFactory.SimpleBaseType(Types.AsyncPackage.TypeSyntax.WithAdditionalAnnotations(Simplifier.Annotation))
.WithLeadingTrivia(baseTypeSyntax.GetLeadingTrivia())
.WithTrailingTrivia(baseTypeSyntax.GetTrailingTrivia());
updatedRoot = updatedRoot.ReplaceNode(baseTypeSyntax, asyncPackageBaseTypeSyntax);
// Update the PackageRegistration attribute
if (packageRegistrationSyntax != null)
{
LiteralExpressionSyntax trueExpression = SyntaxFactory.LiteralExpression(SyntaxKind.TrueLiteralExpression);
packageRegistrationSyntax = updatedRoot.GetCurrentNode(packageRegistrationSyntax);
AttributeArgumentSyntax allowsBackgroundLoadingSyntax = packageRegistrationSyntax.ArgumentList.Arguments.FirstOrDefault(a => a.NameEquals?.Name?.Identifier.Text == Types.PackageRegistrationAttribute.AllowsBackgroundLoading);
if (allowsBackgroundLoadingSyntax != null)
{
updatedRoot = updatedRoot.ReplaceNode(
allowsBackgroundLoadingSyntax,
allowsBackgroundLoadingSyntax.WithExpression(trueExpression));
}
else
{
updatedRoot = updatedRoot.ReplaceNode(
packageRegistrationSyntax,
packageRegistrationSyntax.AddArgumentListArguments(
SyntaxFactory.AttributeArgument(trueExpression).WithNameEquals(SyntaxFactory.NameEquals(Types.PackageRegistrationAttribute.AllowsBackgroundLoading))));
}
}
// Find the Initialize override, if present, and update it to InitializeAsync
if (initializeMethodSyntax != null)
{
IdentifierNameSyntax cancellationTokenLocalVarName = SyntaxFactory.IdentifierName("cancellationToken");
IdentifierNameSyntax progressLocalVarName = SyntaxFactory.IdentifierName("progress");
initializeMethodSyntax = updatedRoot.GetCurrentNode(initializeMethodSyntax);
BlockSyntax newBody = initializeMethodSyntax.Body;
SyntaxTriviaList leadingTrivia = SyntaxFactory.TriviaList(
SyntaxFactory.Comment(@"// When initialized asynchronously, we *may* be on a background thread at this point."),
SyntaxFactory.CarriageReturnLineFeed,
SyntaxFactory.Comment(@"// Do any initialization that requires the UI thread after switching to the UI thread."),
SyntaxFactory.CarriageReturnLineFeed,
SyntaxFactory.Comment(@"// Otherwise, remove the switch to the UI thread if you don't need it."),
SyntaxFactory.CarriageReturnLineFeed);
ExpressionStatementSyntax switchToMainThreadStatement = SyntaxFactory.ExpressionStatement(
SyntaxFactory.AwaitExpression(
SyntaxFactory.InvocationExpression(
SyntaxFactory.MemberAccessExpression(
SyntaxKind.SimpleMemberAccessExpression,
SyntaxFactory.MemberAccessExpression(
SyntaxKind.SimpleMemberAccessExpression,
SyntaxFactory.ThisExpression(),
SyntaxFactory.IdentifierName(Types.ThreadHelper.JoinableTaskFactory)),
SyntaxFactory.IdentifierName(Types.JoinableTaskFactory.SwitchToMainThreadAsync)))
.AddArgumentListArguments(SyntaxFactory.Argument(cancellationTokenLocalVarName))))
.WithLeadingTrivia(leadingTrivia)
.WithTrailingTrivia(SyntaxFactory.CarriageReturnLineFeed);
if (baseInitializeInvocationSyntax != null)
{
var baseInitializeAsyncInvocationBookmark = new SyntaxAnnotation();
AwaitExpressionSyntax baseInitializeAsyncInvocationSyntax = SyntaxFactory.AwaitExpression(
baseInitializeInvocationSyntax
.WithLeadingTrivia()
.WithExpression(
SyntaxFactory.MemberAccessExpression(
SyntaxKind.SimpleMemberAccessExpression,
SyntaxFactory.BaseExpression(),
SyntaxFactory.IdentifierName(Types.AsyncPackage.InitializeAsync)))
.AddArgumentListArguments(
SyntaxFactory.Argument(cancellationTokenLocalVarName),
SyntaxFactory.Argument(progressLocalVarName)))
.WithLeadingTrivia(baseInitializeInvocationSyntax.GetLeadingTrivia())
.WithAdditionalAnnotations(baseInitializeAsyncInvocationBookmark);
newBody = newBody.ReplaceNode(initializeMethodSyntax.GetCurrentNode(baseInitializeInvocationSyntax), baseInitializeAsyncInvocationSyntax);
StatementSyntax baseInvocationStatement = newBody.GetAnnotatedNodes(baseInitializeAsyncInvocationBookmark).First().FirstAncestorOrSelf <StatementSyntax>();
newBody = newBody.InsertNodesAfter(
baseInvocationStatement,
new[] { switchToMainThreadStatement.WithLeadingTrivia(switchToMainThreadStatement.GetLeadingTrivia().Insert(0, SyntaxFactory.LineFeed)) });
}
else
{
newBody = newBody.WithStatements(
newBody.Statements.Insert(0, switchToMainThreadStatement));
}
MethodDeclarationSyntax initializeAsyncMethodSyntax = initializeMethodSyntax
.WithIdentifier(SyntaxFactory.Identifier(Types.AsyncPackage.InitializeAsync))
.WithReturnType(Types.Task.TypeSyntax.WithAdditionalAnnotations(Simplifier.Annotation))
.AddModifiers(SyntaxFactory.Token(SyntaxKind.AsyncKeyword))
.AddParameterListParameters(
SyntaxFactory.Parameter(cancellationTokenLocalVarName.Identifier).WithType(Types.CancellationToken.TypeSyntax.WithAdditionalAnnotations(Simplifier.Annotation)),
SyntaxFactory.Parameter(progressLocalVarName.Identifier).WithType(Types.IProgress.TypeSyntaxOf(Types.ServiceProgressData.TypeSyntax).WithAdditionalAnnotations(Simplifier.Annotation)))
.WithBody(newBody);
updatedRoot = updatedRoot.ReplaceNode(initializeMethodSyntax, initializeAsyncMethodSyntax);
// Replace GetService calls with GetServiceAsync
getServiceInvocationsSyntax = updatedRoot.GetCurrentNodes <InvocationExpressionSyntax>(getServiceInvocationsSyntax).ToList();
updatedRoot = updatedRoot.ReplaceNodes(
getServiceInvocationsSyntax,
(orig, node) =>
{
InvocationExpressionSyntax invocation = node;
if (invocation.Expression is IdentifierNameSyntax methodName)
{
invocation = invocation.WithExpression(SyntaxFactory.IdentifierName(Types.AsyncPackage.GetServiceAsync));
}
else if (invocation.Expression is MemberAccessExpressionSyntax memberAccess)
{
invocation = invocation.WithExpression(
memberAccess.WithName(SyntaxFactory.IdentifierName(Types.AsyncPackage.GetServiceAsync)));
}
return(SyntaxFactory.ParenthesizedExpression(SyntaxFactory.AwaitExpression(invocation))
.WithAdditionalAnnotations(Simplifier.Annotation));
});
updatedRoot = await Utils.AddUsingTaskEqualsDirectiveAsync(updatedRoot, cancellationToken);
}
Document newDocument = context.Document.WithSyntaxRoot(updatedRoot);
newDocument = await ImportAdder.AddImportsAsync(newDocument, Simplifier.Annotation, cancellationToken : cancellationToken);
return(newDocument);
}