private static bool CanBeMergedWithParent(
ISyntaxFactsService syntaxFacts,
IIfLikeStatementGenerator ifGenerator,
SyntaxNode ifOrElseIf,
out SyntaxNode parentIfOrElseIf)
{
return(ifGenerator.IsElseIfClause(ifOrElseIf, out parentIfOrElseIf) &&
ContainEquivalentStatements(syntaxFacts, ifOrElseIf, parentIfOrElseIf, out _));
}
private static async Task <bool> CanBeSeparateStatementsAsync(
Document document,
ISyntaxFactsService syntaxFacts,
IIfLikeStatementGenerator ifGenerator,
SyntaxNode ifOrElseIf,
CancellationToken cancellationToken
)
{
// In order to make separate statements, ifOrElseIf must be an if statement, not an else-if clause.
if (ifGenerator.IsElseIfClause(ifOrElseIf, out _))
{
return(false);
}
// If there is an else clause, we *could* in theory separate these and move the current else clause to the second
// statement, but we won't. It would break the else-if chain in an odd way. We'll insert an else-if instead.
if (ifGenerator.GetElseIfAndElseClauses(ifOrElseIf).Length > 0)
{
return(false);
}
var insideStatements = syntaxFacts.GetStatementContainerStatements(ifOrElseIf);
if (insideStatements.Count == 0)
{
// Even though there are no statements inside, we still can't split this into separate statements
// because it would change the semantics from short-circuiting to always evaluating the second condition,
// breaking code like 'if (a == null || a.InstanceMethod())'.
return(false);
}
else
{
// There are statements inside. We can split this into separate statements and leave out the 'else' if
// control flow can't reach the end of these statements (otherwise, it would continue to the second 'if'
// and in the case that both conditions are true, run the same statements twice).
// This will typically look like a single return, break, continue or a throw statement.
var semanticModel = await document
.GetSemanticModelAsync(cancellationToken)
.ConfigureAwait(false);
var controlFlow = semanticModel.AnalyzeControlFlow(
insideStatements[0],
insideStatements[insideStatements.Count - 1]
);
return(!controlFlow.EndPointIsReachable);
}
}