public static Task <Document> RefactorAsync(
Document document,
IfStatementSyntax ifStatement,
CancellationToken cancellationToken)
{
var statement = (ExpressionStatementSyntax)ifStatement.GetSingleStatementOrDefault();
MemberInvocationStatementInfo invocationInfo = SyntaxInfo.MemberInvocationStatementInfo(statement);
int insertIndex = invocationInfo.Expression.Span.End - statement.FullSpan.Start;
StatementSyntax newStatement = SyntaxFactory.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 &&
ifStatement.TryGetContainingList(out SyntaxList <StatementSyntax> statements) &&
!IsPartOfLazyInitialization(ifStatement, statements))
{
NullCheckExpressionInfo nullCheck = SyntaxInfo.NullCheckExpressionInfo(ifStatement.Condition, semanticModel: context.SemanticModel, cancellationToken: context.CancellationToken);
if (nullCheck.Success)
{
SimpleAssignmentStatementInfo assignmentInfo = SyntaxInfo.SimpleAssignmentStatementInfo(ifStatement.GetSingleStatementOrDefault());
if (assignmentInfo.Success &&
SyntaxComparer.AreEquivalent(assignmentInfo.Left, nullCheck.Expression) &&
assignmentInfo.Right.IsSingleLine() &&
!ifStatement.SpanContainsDirectives())
{
int index = statements.IndexOf(ifStatement);
if (index > 0)
{
StatementSyntax previousStatement = statements[index - 1];
if (!previousStatement.ContainsDiagnostics &&
CanRefactor(previousStatement, ifStatement, nullCheck.Expression, ifStatement.Parent))
{
context.ReportDiagnostic(DiagnosticDescriptors.UseCoalesceExpression, previousStatement);
}
}
if (index < statements.Count - 1)
{
StatementSyntax nextStatement = statements[index + 1];
if (!nextStatement.ContainsDiagnostics)
{
MemberInvocationStatementInfo invocationInfo = SyntaxInfo.MemberInvocationStatementInfo(nextStatement);
if (invocationInfo.Success &&
SyntaxComparer.AreEquivalent(nullCheck.Expression, invocationInfo.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)
{
NullCheckExpressionInfo nullCheck = SyntaxInfo.NullCheckExpressionInfo(ifStatement.Condition, allowedKinds: NullCheckKind.NotEqualsToNull);
if (nullCheck.Success)
{
MemberInvocationStatementInfo invocationInfo = SyntaxInfo.MemberInvocationStatementInfo(ifStatement.GetSingleStatementOrDefault());
if (invocationInfo.Success &&
SyntaxComparer.AreEquivalent(nullCheck.Expression, invocationInfo.Expression) &&
!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)
{
StatementsInfo statementsInfo = SyntaxInfo.StatementsInfo(ifStatement);
SyntaxList <StatementSyntax> statements = statementsInfo.Statements;
int index = statements.IndexOf(ifStatement);
StatementSyntax expressionStatement = (ExpressionStatementSyntax)statements[index + 1];
MemberInvocationStatementInfo invocationInfo = SyntaxInfo.MemberInvocationStatementInfo((ExpressionStatementSyntax)expressionStatement);
ExpressionSyntax expression = invocationInfo.Expression;
SimpleAssignmentStatementInfo assignmentInfo = SyntaxInfo.SimpleAssignmentStatementInfo((ExpressionStatementSyntax)ifStatement.GetSingleStatementOrDefault());
BinaryExpressionSyntax coalesceExpression = CSharpFactory.CoalesceExpression(expression.WithoutTrivia(), ParenthesizedExpression(assignmentInfo.AssignmentExpression));
ParenthesizedExpressionSyntax newExpression = ParenthesizedExpression(coalesceExpression)
.WithTriviaFrom(expression);
StatementSyntax newExpressionStatement = expressionStatement.ReplaceNode(expression, newExpression);
IEnumerable <SyntaxTrivia> trivia = statementsInfo.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.ReplaceStatementsAsync(statementsInfo, newStatements, cancellationToken));
}