public static void ComputeRefactoring(RefactoringContext context, SelectedStatementsInfo info)
{
if (info.IsSingleSelected)
{
StatementSyntax[] statements = info.SelectedNodes().ToArray();
StatementSyntax first = statements[0];
if (first.IsKind(SyntaxKind.IfStatement))
{
var ifStatement = (IfStatementSyntax)first;
if (IfElseAnalysis.IsTopmostIf(ifStatement) &&
CanBeReplacedWithSwitch(ifStatement))
{
string title = (IfElseAnalysis.IsIsolatedIf(ifStatement))
? "Replace if with switch"
: "Replace if-else with switch";
context.RegisterRefactoring(
title,
cancellationToken =>
{
return(RefactorAsync(
context.Document,
ifStatement,
cancellationToken));
});
}
}
}
}
private void AnalyzeStatement(SyntaxNodeAnalysisContext context)
{
if (GeneratedCodeAnalyzer?.IsGeneratedCode(context) == true)
{
return;
}
AnalyzeEmbeddedStatement(context);
if (context.Node.IsKind(SyntaxKind.IfStatement) &&
!IfElseAnalysis.IsIsolatedIf((IfStatementSyntax)context.Node))
{
return;
}
StatementSyntax statement = EmbeddedStatementAnalysis.GetEmbeddedStatementThatShouldBeInsideBlock(context.Node);
if (statement != null)
{
context.ReportDiagnostic(
DiagnosticDescriptors.AddBraces,
statement.GetLocation(),
SyntaxHelper.GetNodeTitle(context.Node));
}
}
public override SyntaxNode VisitIfStatement(IfStatementSyntax node)
{
if (node == null)
{
throw new ArgumentNullException(nameof(node));
}
if (_previousIf == null || _previousIf.Equals(IfElseAnalysis.GetPreviousIf(node)))
{
if (node.Statement != null &&
!node.Statement.IsKind(SyntaxKind.Block))
{
IfStatementSyntax ifStatement = node.WithStatement(SyntaxFactory.Block(node.Statement));
_previousIf = ifStatement;
return(base.VisitIfStatement(ifStatement));
}
else
{
_previousIf = node;
}
}
return(base.VisitIfStatement(node));
}
private void AnalyzeStatement(SyntaxNodeAnalysisContext context)
{
if (GeneratedCodeAnalyzer?.IsGeneratedCode(context) == true)
{
return;
}
if (!context.Node.IsKind(SyntaxKind.IfStatement) ||
IfElseAnalysis.IsIsolatedIf((IfStatementSyntax)context.Node))
{
BlockSyntax block = EmbeddedStatementAnalysis.GetBlockThatCanBeEmbeddedStatement(context.Node);
if (block != null &&
!block.OpenBraceToken.IsMissing &&
!block.CloseBraceToken.IsMissing &&
block.OpenBraceToken.LeadingTrivia.All(f => f.IsWhitespaceOrEndOfLineTrivia()) &&
block.OpenBraceToken.TrailingTrivia.All(f => f.IsWhitespaceOrEndOfLineTrivia()) &&
block.CloseBraceToken.LeadingTrivia.All(f => f.IsWhitespaceOrEndOfLineTrivia()) &&
block.CloseBraceToken.TrailingTrivia.All(f => f.IsWhitespaceOrEndOfLineTrivia()))
{
context.ReportDiagnostic(
DiagnosticDescriptors.RemoveBraces,
block.GetLocation(),
SyntaxHelper.GetNodeTitle(context.Node));
context.FadeOutBraces(DiagnosticDescriptors.RemoveBracesFadeOut, block);
}
}
}
private static bool CheckContainingNode(SyntaxNode node)
{
switch (node.Kind())
{
case SyntaxKind.ForEachStatement:
case SyntaxKind.ForStatement:
case SyntaxKind.UsingStatement:
case SyntaxKind.WhileStatement:
case SyntaxKind.DoStatement:
case SyntaxKind.LockStatement:
case SyntaxKind.FixedStatement:
case SyntaxKind.UnsafeStatement:
case SyntaxKind.TryStatement:
case SyntaxKind.CheckedStatement:
case SyntaxKind.UncheckedStatement:
return(true);
case SyntaxKind.IfStatement:
return(IfElseAnalysis.IsTopmostIf((IfStatementSyntax)node));
case SyntaxKind.ElseClause:
return(IfElseAnalysis.IsEndOfChain((ElseClauseSyntax)node));
}
return(false);
}
private static IEnumerable <SwitchSectionSyntax> CreateSwitchSections(IfStatementSyntax ifStatement)
{
foreach (SyntaxNode node in IfElseAnalysis.GetChain(ifStatement))
{
if (node.IsKind(SyntaxKind.IfStatement))
{
ifStatement = (IfStatementSyntax)node;
var condition = ifStatement.Condition as BinaryExpressionSyntax;
List <SwitchLabelSyntax> labels = CreateSwitchLabels(condition, new List <SwitchLabelSyntax>());
labels.Reverse();
SwitchSectionSyntax section = SwitchSection(
List(labels),
AddBreakStatementIfNecessary(ifStatement.Statement));
yield return(section);
}
else
{
var elseClause = (ElseClauseSyntax)node;
yield return(DefaultSwitchSection(AddBreakStatementIfNecessary(elseClause.Statement)));
}
}
}
private static SyntaxNode GetContainingBlock(SyntaxNode node)
{
if (node.IsKind(SyntaxKind.ElseClause))
{
return(IfElseAnalysis.GetTopmostIf((ElseClauseSyntax)node)?.Parent);
}
else
{
return(node.Parent);
}
}
internal IfElseAnalysisResult(IfStatementSyntax ifStatement)
{
if (ifStatement == null)
{
throw new ArgumentNullException(nameof(ifStatement));
}
bool anyHasEmbedded = false;
bool anyHasBlock = false;
bool allSupportsEmbedded = true;
int cnt = 0;
foreach (SyntaxNode node in IfElseAnalysis.GetChain(ifStatement))
{
cnt++;
StatementSyntax statement = GetStatement(node);
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)
{
AddBraces = true;
return;
}
}
if (cnt > 1 &&
allSupportsEmbedded &&
anyHasBlock)
{
RemoveBraces = true;
if (anyHasEmbedded)
{
AddBraces = true;
}
}
}
public static bool CanRefactor(
IfStatementSyntax ifStatement,
SemanticModel semanticModel,
CancellationToken cancellationToken = default(CancellationToken))
{
if (IfElseAnalysis.IsTopmostIf(ifStatement))
{
ElseClauseSyntax elseClause = ifStatement.Else;
if (elseClause != null)
{
ExpressionSyntax condition = ifStatement.Condition;
if (condition != null)
{
ITypeSymbol typeSymbol = semanticModel.GetTypeSymbol(condition, cancellationToken);
if (typeSymbol?.IsBoolean() == true)
{
AssignmentExpressionSyntax trueExpression = GetSimpleAssignmentExpression(ifStatement.Statement);
ExpressionSyntax trueRight = trueExpression?.Right;
if (trueRight?.IsBooleanLiteralExpression() == true)
{
AssignmentExpressionSyntax falseExpression = GetSimpleAssignmentExpression(elseClause.Statement);
ExpressionSyntax falseRight = falseExpression?.Right;
if (falseRight?.IsBooleanLiteralExpression() == true)
{
var trueBooleanLiteral = (LiteralExpressionSyntax)trueRight;
var falseBooleanLiteral = (LiteralExpressionSyntax)falseRight;
if (trueBooleanLiteral.IsKind(SyntaxKind.TrueLiteralExpression) != falseBooleanLiteral.IsKind(SyntaxKind.TrueLiteralExpression) &&
trueExpression.Left?.IsEquivalentTo(falseExpression.Left, topLevel: false) == true)
{
return(true);
}
}
}
}
}
}
}
return(false);
}
private static IfStatementSyntax GetTopmostIf(BlockSyntax block)
{
SyntaxNode parent = block.Parent;
switch (parent?.Kind())
{
case SyntaxKind.IfStatement:
return(IfElseAnalysis.GetTopmostIf((IfStatementSyntax)parent));
case SyntaxKind.ElseClause:
return(IfElseAnalysis.GetTopmostIf((ElseClauseSyntax)parent));
default:
return(null);
}
}
private static SyntaxNode GetNewRoot(StatementSyntax statement, SyntaxNode oldRoot, IEnumerable <StatementSyntax> newNodes)
{
if (statement.Parent.IsKind(SyntaxKind.ElseClause))
{
IfStatementSyntax ifStatement = IfElseAnalysis.GetTopmostIf((ElseClauseSyntax)statement.Parent);
var block = (BlockSyntax)ifStatement.Parent;
int index = block.Statements.IndexOf(ifStatement);
BlockSyntax newBlock = block.RemoveNode(statement.Parent, SyntaxRemoveOptions.KeepNoTrivia);
newBlock = newBlock.WithStatements(newBlock.Statements.InsertRange(index + 1, newNodes));
return(oldRoot.ReplaceNode(block, newBlock));
}
else
{
return(oldRoot.ReplaceNode(statement.Parent, newNodes));
}
}
public static void Analyze(SyntaxNodeAnalysisContext context, IfStatementSyntax ifStatement)
{
if (IfElseAnalysis.IsIsolatedIf(ifStatement) &&
ConditionAllowsMerging(ifStatement.Condition))
{
IfStatementSyntax nestedIf = GetNestedIfStatement(ifStatement);
if (nestedIf != null &&
nestedIf.Else == null &&
ConditionAllowsMerging(nestedIf.Condition) &&
TriviaAllowsMerging(ifStatement, nestedIf))
{
context.ReportDiagnostic(
DiagnosticDescriptors.MergeIfStatementWithNestedIfStatement,
ifStatement.GetLocation());
FadeOut(context, ifStatement, nestedIf);
}
}
}
private static bool CanBeReplacedWithSwitch(IfStatementSyntax ifStatement)
{
foreach (SyntaxNode node in IfElseAnalysis.GetChain(ifStatement))
{
if (node.IsKind(SyntaxKind.IfStatement))
{
ifStatement = (IfStatementSyntax)node;
var condition = ifStatement.Condition as BinaryExpressionSyntax;
if (condition == null ||
!IsValidCondition(condition, null))
{
return(false);
}
}
}
return(true);
}
public sealed override async Task RegisterCodeFixesAsync(CodeFixContext context)
{
SyntaxNode root = await context.Document.GetSyntaxRootAsync(context.CancellationToken).ConfigureAwait(false);
IfStatementSyntax ifStatement = root
.FindNode(context.Span, getInnermostNodeForTie: true)?
.FirstAncestorOrSelf <IfStatementSyntax>();
if (ifStatement == null)
{
return;
}
ifStatement = IfElseAnalysis.GetTopmostIf(ifStatement);
CodeAction codeAction = CodeAction.Create(
"Add braces to if-else",
cancellationToken => AddBracesToIfElseRefactoring.RefactorAsync(context.Document, ifStatement, cancellationToken),
DiagnosticIdentifiers.AddBracesToIfElse + EquivalenceKeySuffix);
context.RegisterCodeFix(codeAction, context.Diagnostics);
}
private static IfStatementSyntax GetTopmostIf(StatementSyntax statement)
{
SyntaxNode parent = statement.Parent;
if (parent != null)
{
if (parent.IsKind(SyntaxKind.ElseClause))
{
return(IfElseAnalysis.GetTopmostIf((ElseClauseSyntax)parent));
}
else
{
var parentStatement = parent as IfStatementSyntax;
if (parentStatement != null)
{
return(IfElseAnalysis.GetTopmostIf(parentStatement));
}
}
}
return(null);
}
public static async Task ComputeRefactoringsAsync(RefactoringContext context, IfStatementSyntax ifStatement)
{
if (context.IsAnyRefactoringEnabled(
RefactoringIdentifiers.SwapStatementsInIfElse,
RefactoringIdentifiers.ReplaceIfElseWithConditionalExpression) &&
IfElseAnalysis.IsTopmostIf(ifStatement) &&
context.Span.IsBetweenSpans(ifStatement))
{
if (context.IsRefactoringEnabled(RefactoringIdentifiers.ReplaceIfElseWithConditionalExpression))
{
ReplaceIfElseWithConditionalExpressionRefactoring.ComputeRefactoring(context, ifStatement);
}
if (context.IsRefactoringEnabled(RefactoringIdentifiers.SwapStatementsInIfElse) &&
SwapStatementInIfElseRefactoring.CanRefactor(ifStatement))
{
context.RegisterRefactoring(
"Swap statements in if-else",
cancellationToken =>
{
return(SwapStatementInIfElseRefactoring.RefactorAsync(
context.Document,
ifStatement,
cancellationToken));
});
}
}
if (context.IsRefactoringEnabled(RefactoringIdentifiers.AddBooleanComparison) &&
ifStatement.Condition != null &&
ifStatement.Condition.Span.Contains(context.Span) &&
context.SupportsSemanticModel)
{
await AddBooleanComparisonRefactoring.ComputeRefactoringAsync(context, ifStatement.Condition).ConfigureAwait(false);
}
}
private static IEnumerable <StatementSyntax> GetEmbeddedStatements(IfStatementSyntax topmostIf)
{
foreach (SyntaxNode node in IfElseAnalysis.GetChain(topmostIf))
{
switch (node.Kind())
{
case SyntaxKind.IfStatement:
{
var ifStatement = (IfStatementSyntax)node;
StatementSyntax statement = ifStatement.Statement;
if (statement?.IsKind(SyntaxKind.Block) == false)
{
yield return(statement);
}
break;
}
case SyntaxKind.ElseClause:
{
var elseClause = (ElseClauseSyntax)node;
StatementSyntax statement = elseClause.Statement;
if (statement?.IsKind(SyntaxKind.Block) == false)
{
yield return(statement);
}
break;
}
}
}
}
private static StatementSyntax GetStatement(
RefactoringContext context,
BlockSyntax block,
SyntaxNode parent)
{
switch (parent?.Kind())
{
case SyntaxKind.WhileStatement:
case SyntaxKind.DoStatement:
case SyntaxKind.ForStatement:
case SyntaxKind.ForEachStatement:
case SyntaxKind.FixedStatement:
case SyntaxKind.CheckedStatement:
case SyntaxKind.UncheckedStatement:
case SyntaxKind.UnsafeStatement:
case SyntaxKind.UsingStatement:
case SyntaxKind.LockStatement:
{
if (block.OpenBraceToken.Span.Contains(context.Span) ||
block.CloseBraceToken.Span.Contains(context.Span))
{
if (parent.IsKind(SyntaxKind.UsingStatement))
{
var usingStatement = (UsingStatementSyntax)parent;
while (usingStatement.Parent?.IsKind(SyntaxKind.UsingStatement) == true)
{
usingStatement = (UsingStatementSyntax)usingStatement.Parent;
}
return(usingStatement);
}
return((StatementSyntax)parent);
}
break;
}
case SyntaxKind.TryStatement:
{
var tryStatement = (TryStatementSyntax)parent;
if (tryStatement.Block?.OpenBraceToken.Span.Contains(context.Span) == true)
{
return((StatementSyntax)parent);
}
break;
}
case SyntaxKind.IfStatement:
{
var ifStatement = (IfStatementSyntax)parent;
if (IfElseAnalysis.IsTopmostIf(ifStatement) &&
block.OpenBraceToken.Span.Contains(context.Span))
{
return(ifStatement);
}
if (ifStatement.Else == null &&
block.CloseBraceToken.Span.Contains(context.Span))
{
return(ifStatement);
}
break;
}
case SyntaxKind.ElseClause:
{
var elseClause = (ElseClauseSyntax)parent;
if (block.CloseBraceToken.Span.Contains(context.Span))
{
return(IfElseAnalysis.GetTopmostIf(elseClause));
}
break;
}
case SyntaxKind.CatchClause:
{
var catchClause = (CatchClauseSyntax)parent;
if (catchClause.Parent?.IsKind(SyntaxKind.TryStatement) == true)
{
var tryStatement = (TryStatementSyntax)catchClause.Parent;
if (tryStatement.Finally == null &&
catchClause.Block?.CloseBraceToken.Span.Contains(context.Span) == true)
{
return(tryStatement);
}
}
break;
}
case SyntaxKind.FinallyClause:
{
var finallyClause = (FinallyClauseSyntax)parent;
if (finallyClause.Parent?.IsKind(SyntaxKind.TryStatement) == true)
{
var tryStatement = (TryStatementSyntax)finallyClause.Parent;
if (finallyClause.Block?.CloseBraceToken.Span.Contains(context.Span) == true)
{
return(tryStatement);
}
}
break;
}
}
return(null);
}
public static void ComputeRefactoring(RefactoringContext context, IfStatementSyntax ifStatement)
{
if (IfElseAnalysis.IsTopmostIf(ifStatement))
{
ElseClauseSyntax elseClause = ifStatement.Else;
if (elseClause != null)
{
StatementSyntax statement2 = elseClause.Statement;
if (statement2?.IsKind(SyntaxKind.IfStatement) == false)
{
StatementSyntax statement1 = GetStatementOrDefault(ifStatement.Statement);
if (statement1 != null)
{
statement2 = GetStatementOrDefault(statement2);
if (statement2 != null)
{
SyntaxKind kind1 = statement1.Kind();
SyntaxKind kind2 = statement2.Kind();
if (kind1 == SyntaxKind.ReturnStatement)
{
if (kind2 == SyntaxKind.ReturnStatement)
{
ComputeRefactoring(
context,
ifStatement,
(ReturnStatementSyntax)statement1,
(ReturnStatementSyntax)statement2);
}
}
else if (kind1 == SyntaxKind.YieldReturnStatement)
{
if (kind2 == SyntaxKind.YieldReturnStatement)
{
ComputeRefactoring(
context,
ifStatement,
(YieldStatementSyntax)statement1,
(YieldStatementSyntax)statement2);
}
}
else if (kind1 == SyntaxKind.ExpressionStatement)
{
if (kind2 == SyntaxKind.ExpressionStatement)
{
ComputeRefactoring(
context,
ifStatement,
(ExpressionStatementSyntax)statement1,
(ExpressionStatementSyntax)statement2);
}
}
}
}
}
}
}
}
