public static Task <Document> RefactorAsync(
Document document,
IfStatementSyntax ifStatement,
CancellationToken cancellationToken)
{
var statement = (ExpressionStatementSyntax)ifStatement.GetSingleStatementOrDefault();
MemberInvocationStatement memberInvocation = MemberInvocationStatement.Create(statement);
int insertIndex = memberInvocation.Expression.Span.End - statement.FullSpan.Start;
StatementSyntax newStatement = ParseStatement(statement.ToFullString().Insert(insertIndex, "?"));
IEnumerable <SyntaxTrivia> leading = ifStatement.DescendantTrivia(TextSpan.FromBounds(ifStatement.SpanStart, statement.SpanStart));
newStatement = (leading.All(f => f.IsWhitespaceOrEndOfLineTrivia()))
? newStatement.WithLeadingTrivia(ifStatement.GetLeadingTrivia())
: newStatement.WithLeadingTrivia(ifStatement.GetLeadingTrivia().Concat(leading));
IEnumerable <SyntaxTrivia> trailing = ifStatement.DescendantTrivia(TextSpan.FromBounds(statement.Span.End, ifStatement.Span.End));
newStatement = (leading.All(f => f.IsWhitespaceOrEndOfLineTrivia()))
? newStatement.WithTrailingTrivia(ifStatement.GetTrailingTrivia())
: newStatement.WithTrailingTrivia(trailing.Concat(ifStatement.GetTrailingTrivia()));
return(document.ReplaceNodeAsync(ifStatement, newStatement, cancellationToken));
}
public static void AnalyzeIfStatement(SyntaxNodeAnalysisContext context)
{
var ifStatement = (IfStatementSyntax)context.Node;
if (ifStatement.IsSimpleIf() &&
!ifStatement.ContainsDiagnostics)
{
SyntaxList <StatementSyntax> statements;
if (ifStatement.TryGetContainingList(out statements) &&
!IsPartOfLazyInitialization(ifStatement, statements))
{
EqualsToNullExpression equalsToNull;
if (EqualsToNullExpression.TryCreate(ifStatement.Condition, out equalsToNull))
{
SimpleAssignmentStatement assignment;
if (SimpleAssignmentStatement.TryCreate(ifStatement.GetSingleStatementOrDefault(), out assignment) &&
SyntaxComparer.AreEquivalent(assignment.Left, equalsToNull.Left) &&
assignment.Right.IsSingleLine() &&
!ifStatement.SpanContainsDirectives())
{
int index = statements.IndexOf(ifStatement);
if (index > 0)
{
StatementSyntax previousStatement = statements[index - 1];
if (!previousStatement.ContainsDiagnostics &&
CanRefactor(previousStatement, ifStatement, equalsToNull.Left, ifStatement.Parent))
{
context.ReportDiagnostic(DiagnosticDescriptors.UseCoalesceExpression, previousStatement);
}
}
if (index < statements.Count - 1)
{
StatementSyntax nextStatement = statements[index + 1];
if (!nextStatement.ContainsDiagnostics)
{
MemberInvocationStatement memberInvocation;
if (MemberInvocationStatement.TryCreate(nextStatement, out memberInvocation) &&
SyntaxComparer.AreEquivalent(equalsToNull.Left, memberInvocation.Expression) &&
!ifStatement.Parent.ContainsDirectives(TextSpan.FromBounds(ifStatement.SpanStart, nextStatement.Span.End)))
{
context.ReportDiagnostic(DiagnosticDescriptors.InlineLazyInitialization, ifStatement);
}
}
}
}
}
}
}
}
public static void AnalyzeIfStatement(SyntaxNodeAnalysisContext context, INamedTypeSymbol expressionType)
{
var ifStatement = (IfStatementSyntax)context.Node;
if (ifStatement.IsSimpleIf() &&
!ifStatement.ContainsDiagnostics)
{
NotEqualsToNullExpression notEqualsToNull;
if (NotEqualsToNullExpression.TryCreate(ifStatement.Condition, out notEqualsToNull))
{
MemberInvocationStatement memberInvocation;
if (MemberInvocationStatement.TryCreate(ifStatement.GetSingleStatementOrDefault(), out memberInvocation) &&
notEqualsToNull.Left.IsEquivalentTo(memberInvocation.Expression, topLevel: false) &&
!ifStatement.IsInExpressionTree(expressionType, context.SemanticModel, context.CancellationToken) &&
!ifStatement.SpanContainsDirectives())
{
context.ReportDiagnostic(DiagnosticDescriptors.UseConditionalAccess, ifStatement);
}
}
}
}
public static Task <Document> InlineLazyInitializationAsync(
Document document,
IfStatementSyntax ifStatement,
CancellationToken cancellationToken)
{
StatementContainer container = StatementContainer.Create(ifStatement);
SyntaxList <StatementSyntax> statements = container.Statements;
int index = statements.IndexOf(ifStatement);
StatementSyntax expressionStatement = (ExpressionStatementSyntax)statements[index + 1];
MemberInvocationStatement invocation = MemberInvocationStatement.Create((ExpressionStatementSyntax)expressionStatement);
ExpressionSyntax expression = invocation.Expression;
SimpleAssignmentStatement assignment = SimpleAssignmentStatement.Create((ExpressionStatementSyntax)ifStatement.GetSingleStatementOrDefault());
BinaryExpressionSyntax coalesceExpression = CSharpFactory.CoalesceExpression(expression.WithoutTrivia(), ParenthesizedExpression(assignment.AssignmentExpression));
ParenthesizedExpressionSyntax newExpression = ParenthesizedExpression(coalesceExpression)
.WithTriviaFrom(expression);
StatementSyntax newExpressionStatement = expressionStatement.ReplaceNode(expression, newExpression);
IEnumerable <SyntaxTrivia> trivia = container.Node.DescendantTrivia(TextSpan.FromBounds(ifStatement.FullSpan.Start, expressionStatement.FullSpan.Start));
if (trivia.Any(f => !f.IsWhitespaceOrEndOfLineTrivia()))
{
newExpressionStatement = newExpressionStatement.PrependToLeadingTrivia(trivia);
}
SyntaxList <StatementSyntax> newStatements = statements
.Replace(expressionStatement, newExpressionStatement)
.RemoveAt(index);
return(document.ReplaceNodeAsync(container.Node, container.NodeWithStatements(newStatements), cancellationToken));
}
