/// <summary>
/// Execute the APM-to-async/await refactoring for a given APM method invocation.
/// </summary>
/// <param name="document">The C# Document on which to operate/in which the Begin and End method calls are represented.</param>
/// <param name="solution">The solution that contains the C# document.</param>
/// <param name="workspace">The workspace to which the code in the syntax tree currently belongs, for formatting purposes.</param>
/// <param name="index">The index number </param>
/// <returns>The CompilationUnitSyntax node that is the result of the transformation.</returns>
public static CompilationUnitSyntax RefactorToTask(Document document, Solution solution, Workspace workspace, int index)
{
if (document == null) throw new ArgumentNullException("document");
if (workspace == null) throw new ArgumentNullException("workspace");
String message;
var numErrorsInSolutionBeforeRewriting = solution.CompilationErrorCount();
var syntaxTree = (SyntaxTree)document.GetSyntaxTreeAsync().Result;
var syntax = (CompilationUnitSyntax)syntaxTree.GetRoot();
Logger.Trace("\n### REFACTORING CODE ###\n{0}\n### END OF CODE ###", syntax.Format(workspace));
InvocationExpressionSyntax beginXxxCall;
try
{
beginXxxCall = document.GetAnnotatedInvocation(index);
}
catch (InvalidOperationException)
{
throw new ArgumentException(
"Syntax tree has no InvocationExpressionSyntax node annotated with RefactorableAPMInstance");
}
var model = (SemanticModel)document.GetSemanticModelAsync().Result;
var callbackArgument = FindAsyncCallbackInvocationArgument(model, beginXxxCall);
var callbackExpression = callbackArgument.Expression;
CompilationUnitSyntax rewrittenSyntax;
switch (callbackExpression.CSharpKind())
{
case SyntaxKind.SimpleLambdaExpression:
var lambda = (SimpleLambdaExpressionSyntax)callbackExpression;
switch (lambda.Body.CSharpKind())
{
case SyntaxKind.Block:
var stateArgument = FindAsyncStateInvocationArgument(model, beginXxxCall);
switch (stateArgument.Expression.CSharpKind())
{
case SyntaxKind.NullLiteralExpression:
Logger.Info("Refactoring:\n{0}", beginXxxCall.ContainingMethod());
return RefactorSimpleLambdaInstance(syntax, beginXxxCall, model, workspace, callbackArgument);
default:
Logger.Info("Rewriting to remove state argument:\n{0}", beginXxxCall);
rewrittenSyntax = RewriteStateArgumentToNull(lambda, syntax, stateArgument);
break;
}
break;
case SyntaxKind.InvocationExpression:
Logger.Info("Rewriting lambda to block form:\n{0}", beginXxxCall);
rewrittenSyntax = RewriteInvocationExpressionToBlock(syntax, lambda, model, beginXxxCall);
break;
default:
message = String
.Format(
"Unsupported lambda body kind: {0}: method:\n{1}",
lambda.Body.CSharpKind(),
beginXxxCall.ContainingMethod()
);
Logger.Error("Not implemented: {0}", message);
throw new NotImplementedException(message);
}
break;
case SyntaxKind.IdentifierName:
case SyntaxKind.SimpleMemberAccessExpression:
Logger.Info("Rewriting method reference to lambda:\n{0}", beginXxxCall);
rewrittenSyntax = RewriteMethodReferenceToSimpleLambda(syntax, beginXxxCall, model, callbackArgument, callbackExpression);
break;
case SyntaxKind.ParenthesizedLambdaExpression:
Logger.Info("Rewriting parenthesized lambda to simple lambda:\n{0}", beginXxxCall);
rewrittenSyntax = RewriteParenthesizedLambdaToSimpleLambda(syntax, beginXxxCall, model);
break;
case SyntaxKind.ObjectCreationExpression:
Logger.Info("Rewriting object creation expression to simple lambda:\n{0}", beginXxxCall);
var objectCreation = (ObjectCreationExpressionSyntax)callbackExpression;
rewrittenSyntax = RewriteObjectCreationToSimpleLambda(syntax, objectCreation, workspace);
break;
case SyntaxKind.AnonymousMethodExpression:
Logger.Info("Rewriting anonymous method (delegate) expression to simple lambda:\n{0}", beginXxxCall);
var anonymousMethod = (AnonymousMethodExpressionSyntax)callbackExpression;
rewrittenSyntax = RewriteAnonymousMethodToSimpleLambda(syntax, anonymousMethod, workspace);
break;
case SyntaxKind.NullLiteralExpression:
message = String.Format("callback is null:\n{0}", beginXxxCall.ContainingMethod());
Logger.Error("Precondition failed: {0}", message);
throw new PreconditionException(message);
case SyntaxKind.InvocationExpression:
message = String
.Format(
"InvocationExpression as callback is not supported: {0}",
beginXxxCall
);
Logger.Error("Precondition failed: {0}", message);
throw new PreconditionException(message);
case SyntaxKind.GenericName:
message = String.Format("GenericName syntax kind is not supported");
Logger.Error("Precondition failed: {0}", message);
throw new PreconditionException(message);
default:
message = String.Format(
"Unsupported actual argument syntax node kind: {0}: callback argument: {1}: in method:\n{2}",
callbackExpression.CSharpKind(),
callbackArgument,
beginXxxCall.ContainingMethod()
);
Logger.Error(message);
throw new NotImplementedException(message);
}
var rewrittenDocument = document.WithSyntaxRoot(rewrittenSyntax);
var rewrittenSolution = solution.WithDocumentSyntaxRoot(document.Id, rewrittenSyntax);
//if (rewrittenSolution.CompilationErrorCount() > numErrorsInSolutionBeforeRewriting)
//{
// Logger.Error(
// "Rewritten solution contains more compilation errors than the original solution while refactoring: {0} @ {1}:{2} in method:\n{3}",
// beginXxxCall,
// beginXxxCall.SyntaxTree.FilePath,
// beginXxxCall.GetStartLineNumber(),
// beginXxxCall.ContainingMethod()
// );
// Logger.Warn("=== SOLUTION ERRORS ===");
// foreach (var diagnostic in rewrittenSolution.GetDiagnostics().Where(d => d.Severity == DiagnosticSeverity.Error))
// {
// Logger.Warn(" - {0}", diagnostic);
// }
// Logger.Warn("=== END OF SOLUTION ERRORS ===");
// Logger.Warn("\n### ORIGINAL CODE ###\n{0}### END OF CODE ###", syntax.Format(workspace));
// Logger.Warn("\n### REWRITTEN CODE ###\n{0}### END OF CODE ###", rewrittenSyntax.Format(workspace));
// throw new RefactoringException("Rewritten solution contains more compilation errors than the original refactoring");
//}
return null;
}
