chaos scroll fix

[pimittens]

Description

The intention of the rand method (which is used to determine stat changes when using chaos scrolls) is to return a pseudorandom uniformly distributed int between lbound and ubound (both inclusive). The previous implementation did not work as intended when the lower bound was negative since java rounds up instead of down when casting a negative double to an int. As a result, +0 was twice as likely as any other result, and -lbound was only possible when nextDouble returned exactly 0. Adding the lower bound after the cast rather than before fixes this since the number being cast to an int will always be positive.

Also changed the CHSCROLL_STAT_RANGE from 6 to 5 in the config to be consistent with gms.

Checklist before requesting a review

• I have performed a self-review of my code
• I have tested my changes

[P0nk]

Good fix, just missing a test.

[P0nk]

Could really use a unit test. I wrote one to test out your change so you might as well just take it:

package tools;

import org.junit.jupiter.api.Test;

import java.util.HashMap;
import java.util.Map;

import static org.junit.jupiter.api.Assertions.assertFalse;
import static org.junit.jupiter.api.Assertions.assertTrue;

class RandomizerTest {

@Test
void randShouldIncludeEntireRange() {
    Map<Integer, Integer> rands = new HashMap<>();

    final int rounds = 100_000;
    for (int i = 0; i < rounds; i++) {
        int randomValue = Randomizer.rand(-5, 5);
        rands.compute(randomValue, (k, v) -> v == null ? 0 : v + 1);
    }

    assertFalse(rands.containsKey(-6));
    assertTrue(rands.containsKey(-5));
    assertTrue(rands.containsKey(-4));
    assertTrue(rands.containsKey(-3));
    assertTrue(rands.containsKey(-2));
    assertTrue(rands.containsKey(-1));
    assertTrue(rands.containsKey(0));
    assertTrue(rands.containsKey(1));
    assertTrue(rands.containsKey(2));
    assertTrue(rands.containsKey(3));
    assertTrue(rands.containsKey(4));
    assertTrue(rands.containsKey(5));
    assertFalse(rands.containsKey(6));
}

}