private T TransformConditionalAccessToIfStatements <T>( T node, SimpleNameSyntax nameNode, ITypeTransformationMetadata typeMetadata, ConditionalAccessExpressionSyntax conditionalAccessNode, InvocationExpressionSyntax invokeNode) where T : SyntaxNode { var statement = (StatementSyntax)conditionalAccessNode.Ancestors().FirstOrDefault(o => o is StatementSyntax); if (statement == null || !(statement.Parent is BlockSyntax block)) { // TODO: convert arrow method/property/function to a normal one // TODO: convert to block if there is no block throw new NotSupportedException( $"Arrow method with null-conditional is not supported. Node: {conditionalAccessNode}"); } var fnName = nameNode.Identifier.ValueText; // TODO: handle name collisions var variableName = $"{char.ToLowerInvariant(fnName[0])}{fnName.Substring(1)}Task"; var leadingTrivia = statement.GetLeadingTrivia(); var newConditionalAccessNode = ConditionalAccessExpression( conditionalAccessNode.Expression, invokeNode) .WithTriviaFrom(conditionalAccessNode); var localVar = LocalDeclarationStatement( VariableDeclaration( IdentifierName(Identifier(leadingTrivia, "var", TriviaList(Space))), SingletonSeparatedList( VariableDeclarator( Identifier(TriviaList(), variableName, TriviaList(Space))) .WithInitializer( EqualsValueClause(newConditionalAccessNode.WithoutTrivia()) .WithEqualsToken(Token(TriviaList(), SyntaxKind.EqualsToken, TriviaList(Space))) ) ))) .WithSemicolonToken(Token(TriviaList(), SyntaxKind.SemicolonToken, TriviaList(typeMetadata.EndOfLineTrivia))); var index = block.Statements.IndexOf(statement); var variableAnnotation = Guid.NewGuid().ToString(); var newBlock = block.ReplaceNode(conditionalAccessNode, conditionalAccessNode.WhenNotNull.ReplaceNode(invokeNode, IdentifierName(variableName) .WithAdditionalAnnotations(new SyntaxAnnotation(variableAnnotation)) .WithLeadingTrivia(conditionalAccessNode.GetLeadingTrivia()) .WithTrailingTrivia(conditionalAccessNode.GetTrailingTrivia()) )); var variable = newBlock.GetAnnotatedNodes(variableAnnotation).OfType <IdentifierNameSyntax>().First(); newBlock = newBlock.ReplaceNode(variable, variable.AddAwait(_configuration.ConfigureAwaitArgument)); var ifBlock = Block() .WithOpenBraceToken( Token(TriviaList(leadingTrivia), SyntaxKind.OpenBraceToken, TriviaList(typeMetadata.EndOfLineTrivia))) .WithCloseBraceToken( Token(TriviaList(leadingTrivia), SyntaxKind.CloseBraceToken, TriviaList(typeMetadata.EndOfLineTrivia))) .WithStatements(SingletonList(newBlock.Statements[index].AppendIndent(typeMetadata.IndentTrivia.ToFullString()))); var ifStatement = IfStatement( BinaryExpression( SyntaxKind.NotEqualsExpression, IdentifierName(Identifier(TriviaList(), variableName, TriviaList(Space))), LiteralExpression(SyntaxKind.NullLiteralExpression)) .WithOperatorToken( Token(TriviaList(), SyntaxKind.ExclamationEqualsToken, TriviaList(Space))), ifBlock ) .WithIfKeyword( Token(TriviaList(leadingTrivia), SyntaxKind.IfKeyword, TriviaList(Space))) .WithCloseParenToken( Token(TriviaList(), SyntaxKind.CloseParenToken, TriviaList(typeMetadata.EndOfLineTrivia))); newBlock = block.WithStatements( block.Statements .RemoveAt(index) .InsertRange(index, new StatementSyntax[] { localVar, ifStatement }) ); return(node.ReplaceNode(block, newBlock)); }
private T TransformConditionalAccessToConditionalExpressions <T>( T node, SimpleNameSyntax nameNode, IFunctionReferenceAnalyzationResult funReferenceResult, ITypeTransformationMetadata typeMetadata, ConditionalAccessExpressionSyntax conditionalAccessNode, InvocationExpressionSyntax invokeNode) where T : SyntaxNode { // TODO: we should check the async symbol instead var returnType = funReferenceResult.ReferenceSymbol.ReturnType; var type = returnType.CreateTypeSyntax(); var canSkipCast = !returnType.IsValueType && !returnType.IsNullable(); if (returnType.IsValueType && !returnType.IsNullable()) { type = NullableType(type); } ExpressionSyntax whenNotNullNode = null; if (invokeNode.Parent is MemberAccessExpressionSyntax memberAccessParent) { whenNotNullNode = conditionalAccessNode.WhenNotNull .ReplaceNode(memberAccessParent, MemberBindingExpression(Token(SyntaxKind.DotToken), memberAccessParent.Name)); } else if (invokeNode.Parent is ElementAccessExpressionSyntax elementAccessParent) { whenNotNullNode = conditionalAccessNode.WhenNotNull .ReplaceNode(elementAccessParent, ElementBindingExpression(elementAccessParent.ArgumentList)); } var valueNode = conditionalAccessNode.Expression.WithoutTrivia(); StatementSyntax variableStatement = null; BlockSyntax statementBlock = null; var statementIndex = 0; // We have to save the value in a variable when the expression is an invocation, index accessor or property in // order to prevent double calls // TODO: find a more robust solution if (!(conditionalAccessNode.Expression is SimpleNameSyntax simpleName) || char.IsUpper(simpleName.ToString()[0])) { var statement = (StatementSyntax)conditionalAccessNode.Ancestors().FirstOrDefault(o => o is StatementSyntax); if (statement == null || !(statement.Parent is BlockSyntax block)) { // TODO: convert arrow method/property/function to a normal one // TODO: convert to block if there is no block throw new NotSupportedException( $"Arrow method with null-conditional is not supported. Node: {conditionalAccessNode}"); } var leadingTrivia = statement.GetLeadingTrivia(); var fnName = nameNode.Identifier.ValueText; statementIndex = block.Statements.IndexOf(statement); statementBlock = block; // TODO: handle name collisions var variableName = $"{char.ToLowerInvariant(fnName[0])}{fnName.Substring(1)}{statementIndex}"; variableStatement = LocalDeclarationStatement( VariableDeclaration( IdentifierName(Identifier(leadingTrivia, "var", TriviaList(Space))), SingletonSeparatedList( VariableDeclarator( Identifier(TriviaList(), variableName, TriviaList(Space))) .WithInitializer( EqualsValueClause(valueNode) .WithEqualsToken(Token(TriviaList(), SyntaxKind.EqualsToken, TriviaList(Space))) ) ))) .WithSemicolonToken(Token(TriviaList(), SyntaxKind.SemicolonToken, TriviaList(typeMetadata.EndOfLineTrivia))); valueNode = IdentifierName(variableName); } var invocationAnnotation = Guid.NewGuid().ToString(); var nullNode = LiteralExpression( SyntaxKind.NullLiteralExpression, Token(TriviaList(), SyntaxKind.NullKeyword, TriviaList(Space))); var ifNullCondition = BinaryExpression( SyntaxKind.EqualsExpression, valueNode.WithTrailingTrivia(TriviaList(Space)), nullNode) .WithOperatorToken( Token(TriviaList(), SyntaxKind.EqualsEqualsToken, TriviaList(Space))); ExpressionSyntax wrappedNode = ParenthesizedExpression( ConditionalExpression( ifNullCondition, canSkipCast ? (ExpressionSyntax)nullNode : CastExpression( Token(SyntaxKind.OpenParenToken), type, Token(TriviaList(), SyntaxKind.CloseParenToken, TriviaList(Space)), nullNode), InvocationExpression( MemberAccessExpression(SyntaxKind.SimpleMemberAccessExpression, valueNode, ((MemberBindingExpressionSyntax)invokeNode.Expression).Name)) .WithAdditionalAnnotations(new SyntaxAnnotation(invocationAnnotation)) .WithArgumentList(invokeNode.ArgumentList.WithoutTrailingTrivia()) ) .WithColonToken(Token(TriviaList(), SyntaxKind.ColonToken, TriviaList(Space))) .WithQuestionToken(Token(TriviaList(), SyntaxKind.QuestionToken, TriviaList(Space))) ); if (whenNotNullNode != null) { wrappedNode = conditionalAccessNode .WithExpression(wrappedNode) .WithWhenNotNull(whenNotNullNode); } wrappedNode = wrappedNode.WithTriviaFrom(conditionalAccessNode); invokeNode = (InvocationExpressionSyntax)wrappedNode.GetAnnotatedNodes(invocationAnnotation).First(); wrappedNode = wrappedNode.ReplaceNode(invokeNode, invokeNode.AddAwait(_configuration.ConfigureAwaitArgument)); if (statementBlock != null) { var newBlock = statementBlock.ReplaceNode(conditionalAccessNode, wrappedNode); newBlock = newBlock.WithStatements(newBlock.Statements.Insert(statementIndex, variableStatement)); return(node.ReplaceNode(statementBlock, newBlock)); } return(node.ReplaceNode(conditionalAccessNode, wrappedNode)); }