private async Task <Document> IntroduceGuardAsync(Document document, SyntaxNode node, HowToGuard g, CancellationToken cancellationToken)
{
// + if (Windows.Foundation.Metadata.ApiInformation.IsTypePresent(targetContainingType))
// {
// old-statement
// + }
try
{
var oldStatement = node.FirstAncestorOrSelf <StatementSyntax>();
var oldLeadingTrivia = oldStatement.GetLeadingTrivia();
var conditionReceiver = SyntaxFactory.ParseName($"Windows.Foundation.Metadata.ApiInformation.{g.KindOfCheck}").WithAdditionalAnnotations(Simplifier.Annotation);
ArgumentListSyntax conditionArgument = null;
if (g.MemberToCheck == null)
{
var conditionString1 = SyntaxFactory.LiteralExpression(SyntaxKind.StringLiteralExpression, SyntaxFactory.Literal(g.TypeToCheck));
conditionArgument = SyntaxFactory.ArgumentList(SyntaxFactory.SingletonSeparatedList(SyntaxFactory.Argument(conditionString1)));
}
else
{
var conditionString1 = SyntaxFactory.LiteralExpression(SyntaxKind.StringLiteralExpression, SyntaxFactory.Literal(g.TypeToCheck));
var conditionString2 = SyntaxFactory.LiteralExpression(SyntaxKind.StringLiteralExpression, SyntaxFactory.Literal(g.MemberToCheck));
var conditionInt3 = SyntaxFactory.LiteralExpression(SyntaxKind.NumericLiteralExpression, SyntaxFactory.Literal(g.ParameterCountToCheck ?? 0));
IEnumerable <ArgumentSyntax> conditions = null;
if (g.ParameterCountToCheck.HasValue)
{
conditions = new ArgumentSyntax[] { SyntaxFactory.Argument(conditionString1), SyntaxFactory.Argument(conditionString2), SyntaxFactory.Argument(conditionInt3) };
}
else
{
conditions = new ArgumentSyntax[] { SyntaxFactory.Argument(conditionString1), SyntaxFactory.Argument(conditionString2) };
}
conditionArgument = SyntaxFactory.ArgumentList(SyntaxFactory.SeparatedList(conditions));
}
var condition = SyntaxFactory.InvocationExpression(conditionReceiver, conditionArgument);
var thenStatements = SyntaxFactory.Block(oldStatement.WithoutLeadingTrivia());
var ifStatement = SyntaxFactory.IfStatement(condition, thenStatements).WithLeadingTrivia(oldLeadingTrivia).WithAdditionalAnnotations(Formatter.Annotation);
var oldRoot = await document.GetSyntaxRootAsync(cancellationToken).ConfigureAwait(false);
var newRoot = oldRoot.ReplaceNode(oldStatement, ifStatement);
return(document.WithSyntaxRoot(newRoot));
}
catch
{
}
return(document);
}
/// <summary>
/// returns instance of <see cref="HowToGuard"/> for <see cref="ISymbol"/>
/// </summary>
/// <param name="target">instance of <see cref="ISymbol"/></param>
/// <returns>instance of <see cref="HowToGuard"/></returns>
public static HowToGuard GetGuardForSymbol(ISymbol target)
{
var plat = Analyzer.GetPlatformForSymbol(target);
switch (plat.Kind)
{
case PlatformKind.ExtensionSDK:
return(new HowToGuard()
{
TypeToCheck = target.Kind == SymbolKind.NamedType ? target.ToDisplayString() : target.ContainingType.ToDisplayString(),
KindOfCheck = "IsTypePresent"
});
case PlatformKind.Uwp:
if (target.Kind == SymbolKind.NamedType)
{
return(new HowToGuard()
{
TypeToCheck = target.ToDisplayString(),
KindOfCheck = "IsTypePresent"
});
}
else
{
var g = new HowToGuard
{
TypeToCheck = target.ContainingType.ToDisplayString()
};
var d0 = Analyzer.GetUniversalApiAdditions(Analyzer.N0DifferencesRes);
var d1 = Analyzer.GetUniversalApiAdditions(Analyzer.N1DifferencesRes);
if (!d0.TryGetValue(g.TypeToCheck, out List <NewMember> newMembers))
{
d1.TryGetValue(g.TypeToCheck, out newMembers);
}
if (newMembers == null)
{
throw new InvalidOperationException("oops! expected this UWP version API to be in the dictionary of new things");
}
g.MemberToCheck = target.Name;
if (target.Kind == SymbolKind.Field)
{
// the only fields in WinRT are enum fields
g.KindOfCheck = "IsEnumNamedValuePresent";
}
else if (target.Kind == SymbolKind.Event)
{
g.KindOfCheck = "IsEventPresent";
}
else if (target.Kind == SymbolKind.Property)
{
// TODO: if SDK starts introducing additional accessors on properties, we'll have to change this
g.KindOfCheck = "IsPropertyPresent";
}
else if (target.Kind == SymbolKind.Method)
{
g.KindOfCheck = "IsMethodPresent";
if (target.Kind == SymbolKind.Method && plat.ByParameterCount)
{
g.ParameterCountToCheck = (target as IMethodSymbol).Parameters.Length;
}
}
return(g);
}
default:
throw new InvalidOperationException("oops! don't know why I was asked to check something that's fine");
}
}