private static bool IsValidExtraction(IExtractMethodInput input, SelectionTarget target)
{
if (target.Parents[target.Parents.Length - 1] is ClassDefinition) {
input.CannotExtract("Cannot extract statements from a class definition");
return false;
}
string invalidExtractMsg = target.InvalidExtractionMessage;
if (invalidExtractMsg != null) {
input.CannotExtract(invalidExtractMsg);
return false;
}
var breakContinueWalker = new ContinueBreakWalker();
target.Walk(breakContinueWalker);
if (breakContinueWalker.ContainsBreak) {
input.CannotExtract("The selection contains a \"break\" statement, but not the enclosing loop");
return false;
} else if (breakContinueWalker.ContainsContinue) {
input.CannotExtract("The selection contains a \"continue\" statement, but not the enclosing loop");
return false;
}
var yieldWalker = new YieldWalker();
target.Walk(yieldWalker);
if (yieldWalker.ContainsYield) {
input.CannotExtract("Cannot extract code containing \"yield\" expression");
return false;
}
var importStarWalker = new ImportStarWalker();
target.Walk(importStarWalker);
if (importStarWalker.ContainsImportStar) {
input.CannotExtract("Cannot extract method containing from ... import * statement");
return false;
}
var returnWalker = new ReturnWalker();
target.Walk(returnWalker);
if (returnWalker.ContainsReturn && !returnWalker.Returns) {
input.CannotExtract("When the selection contains a return statement, all code paths must be terminated by a return statement too.");
return false;
}
target.ContainsReturn = returnWalker.ContainsReturn;
return true;
}
