private static async Task <Document> CreateMappingLambda(Document document, InvocationExpressionSyntax invocation, CancellationToken cancellationToken)
{
var semanticModel = await document.GetSemanticModelAsync(cancellationToken);
var syntaxGenerator = SyntaxGenerator.GetGenerator(document);
var methodInvocationSymbol = semanticModel.GetSymbolInfo(invocation.Expression);
var mappingOverload = methodInvocationSymbol.CandidateSymbols.OfType <IMethodSymbol>().FirstOrDefault(IsMappingMethod);
if (mappingOverload == null)
{
return(document);
}
var sourceElementType = ((INamedTypeSymbol)mappingOverload.Parameters[0].Type).TypeArguments[0];
var targetElementType = GetExpressionType(semanticModel, invocation);
if (targetElementType == null)
{
return(document);
}
var contextAssembly = semanticModel.FindContextAssembly(invocation);
var mappingEngine = new MappingEngine(semanticModel, syntaxGenerator, contextAssembly);
var mappingLambda = mappingEngine.CreateMappingLambda("x", sourceElementType, targetElementType, new MappingPath());
return(await document.ReplaceNodes(invocation, invocation.WithArgumentList(SyntaxFactory.ArgumentList().AddArguments(SyntaxFactory.Argument((ExpressionSyntax)mappingLambda))), cancellationToken));
}