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));
}