private static ImmutableArray <IfAnalysis> ToImmutableArray(IfAnalysis refactoring1, IfAnalysis refactoring2)
{
if (refactoring1 != null)
{
if (refactoring2 != null)
{
return(ImmutableArray.Create(refactoring1, refactoring2));
}
else
{
return(refactoring1.ToImmutableArray());
}
}
else if (refactoring2 != null)
{
return(refactoring2.ToImmutableArray());
}
return(Empty);
}
private static ImmutableArray <IfAnalysis> Analyze(
IfStatementSyntax ifStatement,
ExpressionSyntax condition,
ExpressionSyntax expression1,
ExpressionSyntax expression2,
IfAnalysisOptions options,
bool isYield,
SemanticModel semanticModel,
CancellationToken cancellationToken)
{
if (expression1?.IsMissing != false)
{
return(Empty);
}
if (expression2?.IsMissing != false)
{
return(Empty);
}
if (options.UseCoalesceExpression ||
options.UseExpression)
{
SyntaxKind kind1 = expression1.Kind();
SyntaxKind kind2 = expression2.Kind();
if (IsBooleanLiteralExpression(kind1) &&
IsBooleanLiteralExpression(kind2) &&
kind1 != kind2)
{
if (options.UseExpression)
{
if (ifStatement.IsSimpleIf() &&
(ifStatement.PreviousStatement() is IfStatementSyntax previousIf) &&
previousIf.IsSimpleIf() &&
(previousIf.SingleNonBlockStatementOrDefault() is ReturnStatementSyntax returnStatement) &&
returnStatement.Expression?.WalkDownParentheses().Kind() == kind1)
{
return(Empty);
}
return(new IfToReturnWithExpressionAnalysis(ifStatement, condition, isYield, negate: kind1 == SyntaxKind.FalseLiteralExpression, semanticModel: semanticModel).ToImmutableArray());
}
return(Empty);
}
NullCheckExpressionInfo nullCheck = SyntaxInfo.NullCheckExpressionInfo(condition, semanticModel: semanticModel, cancellationToken: cancellationToken);
if (nullCheck.Success)
{
IfAnalysis refactoring = CreateIfToReturnStatement(
ifStatement,
(nullCheck.IsCheckingNull) ? expression2 : expression1,
(nullCheck.IsCheckingNull) ? expression1 : expression2,
nullCheck,
options,
isYield,
semanticModel,
cancellationToken);
if (refactoring != null)
{
return(refactoring.ToImmutableArray());
}
}
}
IfToReturnWithBooleanExpressionAnalysis ifToReturnWithBooleanExpression = null;
if (options.UseBooleanExpression &&
(IsBooleanLiteralExpression(expression1.Kind()) || IsBooleanLiteralExpression(expression2.Kind())) &&
semanticModel.GetTypeSymbol(expression1, cancellationToken)?.SpecialType == SpecialType.System_Boolean &&
semanticModel.GetTypeSymbol(expression2, cancellationToken)?.SpecialType == SpecialType.System_Boolean)
{
ifToReturnWithBooleanExpression = IfToReturnWithBooleanExpressionAnalysis.Create(ifStatement, expression1, expression2, semanticModel, isYield);
}
IfToReturnWithConditionalExpressionAnalysis ifToReturnWithConditionalExpression = null;
if (options.UseConditionalExpression &&
(!IsBooleanLiteralExpression(expression1.Kind()) || !IsBooleanLiteralExpression(expression2.Kind())) &&
!IsNullLiteralConvertedToNullableOfT(expression1, semanticModel, cancellationToken) &&
!IsNullLiteralConvertedToNullableOfT(expression2, semanticModel, cancellationToken))
{
ifToReturnWithConditionalExpression = IfToReturnWithConditionalExpressionAnalysis.Create(ifStatement, expression1, expression2, semanticModel, isYield);
}
return(ToImmutableArray(ifToReturnWithBooleanExpression, ifToReturnWithConditionalExpression));
}
private static ImmutableArray <IfAnalysis> Analyze(
IfStatementSyntax ifStatement,
ExpressionSyntax condition,
ExpressionStatementSyntax expressionStatement1,
ExpressionStatementSyntax expressionStatement2,
IfAnalysisOptions options,
SemanticModel semanticModel,
CancellationToken cancellationToken)
{
SimpleAssignmentStatementInfo assignment1 = SyntaxInfo.SimpleAssignmentStatementInfo(expressionStatement1);
if (!assignment1.Success)
{
return(Empty);
}
SimpleAssignmentStatementInfo assignment2 = SyntaxInfo.SimpleAssignmentStatementInfo(expressionStatement2);
if (!assignment2.Success)
{
return(Empty);
}
ExpressionSyntax left1 = assignment1.Left;
ExpressionSyntax left2 = assignment2.Left;
ExpressionSyntax right1 = assignment1.Right;
ExpressionSyntax right2 = assignment2.Right;
if (!AreEquivalent(left1, left2))
{
return(Empty);
}
if (options.UseCoalesceExpression ||
options.UseExpression)
{
SyntaxKind kind1 = right1.Kind();
SyntaxKind kind2 = right2.Kind();
if (IsBooleanLiteralExpression(kind1) &&
IsBooleanLiteralExpression(kind2) &&
kind1 != kind2)
{
if (options.UseExpression)
{
return(new IfElseToAssignmentWithConditionAnalysis(ifStatement, left1, condition, semanticModel, negate: kind1 == SyntaxKind.FalseLiteralExpression).ToImmutableArray());
}
return(Empty);
}
NullCheckExpressionInfo nullCheck = SyntaxInfo.NullCheckExpressionInfo(condition, semanticModel: semanticModel, cancellationToken: cancellationToken);
if (nullCheck.Success)
{
IfAnalysis refactoring = CreateIfToAssignment(
ifStatement,
left1,
(nullCheck.IsCheckingNull) ? right2 : right1,
(nullCheck.IsCheckingNull) ? right1 : right2,
nullCheck,
options,
semanticModel,
cancellationToken);
if (refactoring != null)
{
return(refactoring.ToImmutableArray());
}
}
}
if (options.UseConditionalExpression &&
!IsNullLiteralConvertedToNullableOfT(right1, semanticModel, cancellationToken) &&
!IsNullLiteralConvertedToNullableOfT(right2, semanticModel, cancellationToken))
{
return(new IfElseToAssignmentWithConditionalExpressionAnalysis(ifStatement, left1, right1, right2, semanticModel).ToImmutableArray());
}
return(Empty);
}