Did you know that Delphi compiler warning "W1035 Return value of function ''%s'' might be undefined" works only with simple types like integers, but never work for managed types like strings or interfaces?

Using FixInsight''s rule W521 you can handle ANY type:

function TForm1.TestInteger: Integer;
begin

end;

Delphi Compiler: W1035 Return value of function ''TForm1.TestInteger'' might be undefined
FixInsight: W521 Return value of function ''TForm1.TestInteger'' might be undefined

function TForm1.TestString: string;
begin

end;
Delphi Compiler: NOTHING
FixInsight: W521 Return value of function ''TForm1.TestString'' might be undefined