private static IEnumerable <SwitchSectionSyntax> CreateSwitchSections(IfStatementSyntax ifStatement)
{
foreach (IfStatementOrElseClause ifOrElse in ifStatement.GetChain())
{
if (ifOrElse.IsIf)
{
ifStatement = ifOrElse.AsIf();
var condition = ifStatement.Condition.WalkDownParentheses() as BinaryExpressionSyntax;
List <SwitchLabelSyntax> labels = CreateSwitchLabels(condition, new List <SwitchLabelSyntax>());
labels.Reverse();
SwitchSectionSyntax section = SwitchSection(
List(labels),
AddBreakStatementIfNecessary(ifStatement.Statement));
yield return(section);
}
else
{
yield return(DefaultSwitchSection(AddBreakStatementIfNecessary(ifOrElse.Statement)));
}
}
}
private static HashSet <AwaitExpressionSyntax> GetAwaitExpressionsFromIfStatement(
IfStatementSyntax ifStatement,
bool endsWithElse)
{
HashSet <AwaitExpressionSyntax> awaitExpressions = null;
foreach (IfStatementOrElseClause ifOrElse in ifStatement.GetChain())
{
if (ifOrElse.IsElse &&
!endsWithElse)
{
return(null);
}
AwaitExpressionSyntax awaitExpression = GetLastReturnAwaitExpressionOfDefault(ifOrElse.Statement);
if (awaitExpression != null)
{
(awaitExpressions ?? (awaitExpressions = new HashSet <AwaitExpressionSyntax>())).Add(awaitExpression);
}
else
{
return(null);
}
}
return(awaitExpressions);
}
public static async Task ComputeRefactoringAsync(RefactoringContext context, IfStatementSyntax ifStatement)
{
if (!ifStatement.IsTopmostIf())
{
return;
}
SemanticModel semanticModel = await context.GetSemanticModelAsync().ConfigureAwait(false);
foreach (IfStatementOrElseClause ifOrElse in ifStatement.GetChain())
{
if (ifOrElse.IsIf)
{
if (!IsFixable(ifOrElse.AsIf(), semanticModel, context.CancellationToken))
{
return;
}
}
else if (ContainsBreakStatementThatBelongsToParentLoop(ifOrElse.AsElse().Statement))
{
return;
}
}
string title = (ifStatement.IsSimpleIf())
? "Replace if with switch"
: "Replace if-else with switch";
context.RegisterRefactoring(
title,
cancellationToken => RefactorAsync(context.Document, ifStatement, cancellationToken));
}
public static BracesAnalysisResult AnalyzeBraces(IfStatementSyntax ifStatement)
{
if (ifStatement == null)
{
throw new ArgumentNullException(nameof(ifStatement));
}
bool anyHasEmbedded = false;
bool anyHasBlock = false;
bool allSupportsEmbedded = true;
int cnt = 0;
foreach (IfStatementOrElseClause ifOrElse in ifStatement.GetChain())
{
cnt++;
StatementSyntax statement = ifOrElse.Statement;
if (!anyHasEmbedded && !statement.IsKind(SyntaxKind.Block))
{
anyHasEmbedded = true;
}
if (!anyHasBlock && statement.IsKind(SyntaxKind.Block))
{
anyHasBlock = true;
}
if (allSupportsEmbedded && !SupportsEmbedded(statement))
{
allSupportsEmbedded = false;
}
if (cnt > 1 && anyHasEmbedded && !allSupportsEmbedded)
{
return(BracesAnalysisResult.AddBraces);
}
}
if (cnt > 1 &&
allSupportsEmbedded &&
anyHasBlock)
{
if (anyHasEmbedded)
{
return(BracesAnalysisResult.AddBraces | BracesAnalysisResult.RemoveBraces);
}
else
{
return(BracesAnalysisResult.RemoveBraces);
}
}
return(BracesAnalysisResult.None);
}
private static IEnumerable <IfStatementSyntax> GetIfStatements(IfStatementSyntax ifStatement)
{
foreach (IfStatementOrElseClause ifOrElse in ifStatement.GetChain())
{
if (ifOrElse.IsIf)
{
yield return(ifOrElse.AsIf());
}
}
}
private static Task <Document> RefactorAsync(
Document document,
IfStatementSyntax ifStatement,
CancellationToken cancellationToken)
{
return(document.ReplaceNodeAsync(ifStatement, GetNewStatements(), cancellationToken));
IEnumerable <StatementSyntax> GetNewStatements()
{
ElseClauseSyntax parentElse = null;
foreach (IfStatementOrElseClause ifOrElse in ifStatement.GetChain())
{
if (ifOrElse.IsIf)
{
IfStatementSyntax newIfStatement = ifOrElse.AsIf();
ElseClauseSyntax elseClause = newIfStatement.Else;
newIfStatement = newIfStatement.WithElse(null);
if (parentElse != null)
{
newIfStatement = newIfStatement.PrependToLeadingTrivia(parentElse.GetLeadingTrivia());
}
if (elseClause != null)
{
newIfStatement = newIfStatement.AppendToTrailingTrivia(CSharpFactory.NewLine());
}
yield return(newIfStatement.WithFormatterAnnotation());
parentElse = ifStatement.Else;
}
else
{
StatementSyntax statement = ifOrElse.Statement;
if (statement is BlockSyntax block)
{
foreach (StatementSyntax newStatement in block.Statements.Select(f => f.WithFormatterAnnotation()))
{
yield return(newStatement);
}
}
else
{
yield return(statement);
}
}
}
}
}
private static IEnumerable <BlockSyntax> GetBlockStatements(IfStatementSyntax ifStatement)
{
foreach (IfStatementOrElseClause ifOrElse in ifStatement.GetChain())
{
StatementSyntax statement = ifOrElse.Statement;
if (statement?.IsKind(SyntaxKind.Block) == true)
{
yield return((BlockSyntax)statement);
}
}
}
private static IEnumerable <StatementSyntax> GetEmbeddedStatements(IfStatementSyntax topmostIf)
{
foreach (IfStatementOrElseClause ifOrElse in topmostIf.GetChain())
{
StatementSyntax statement = ifOrElse.Statement;
if (statement?.IsKind(SyntaxKind.Block) == false)
{
yield return(statement);
}
}
}
public static void ComputeRefactoring(RefactoringContext context, IfStatementSyntax ifStatement)
{
if (ifStatement.IsParentKind(SyntaxKind.ElseClause))
{
return;
}
if (ifStatement.Else == null)
{
return;
}
foreach (IfStatementOrElseClause ifOrElse in ifStatement.GetChain())
{
StatementSyntax statement = ifOrElse.Statement;
if (statement is BlockSyntax block)
{
statement = block.Statements.LastOrDefault();
}
if (statement == null)
{
return;
}
if (!statement.IsKind(
SyntaxKind.ReturnStatement,
SyntaxKind.ContinueStatement,
SyntaxKind.BreakStatement,
SyntaxKind.ThrowStatement))
{
return;
}
}
context.RegisterRefactoring(
"Split if-else",
cancellationToken => RefactorAsync(context.Document, ifStatement, cancellationToken));
}