Command Line Runner accepts negative int arguments

[Daniel Mitterdorfer]

Hi,

the other day I've run a benchmark where I've defined the number of
iterations by a command line parameter. Instead of e.g. "-i 5" I've
mistyped it as "-i -5" (which is obviously not a good idea ;)).

However, JMH happily accepted the negative iteration count but did not run
any benchmark iterations and printed funny ETAs like "Run progress: -0,00%
complete, ETA 00:-1:-15".

I've looked at org.openjdk.jmh.runner.options.CommandLineOptions and indeed
there is no check on any of the int arguments for negative values.

To stick with my iteration example, instead of:

iterations = Optional.eitherOf(optMeasureCount.value(set));

I'd expect something along the lines of:

if (set.has(optMeasureCount)) {
  Integer value = optMeasureCount.value(set);
  if (value <= 0) {
      throw new CommandLineOptionException("Encountered " + value + " but
expected a positive value");
  }
  iterations = Optional.of(value);
}

To be honest, I don't think that it is such a big problem but fixing it
would make for a more robust user experience.

Bye,

Daniel