ExponentialDelayTest.java

package com.lambdaworks.redis.resource;

import static org.assertj.core.api.Assertions.assertThat;

import java.util.concurrent.TimeUnit;

import org.junit.Test;

/**
 * @author Mark Paluch
 */
public class ExponentialDelayTest {

    @Test(expected = IllegalArgumentException.class)
    public void shouldNotCreateIfLowerBoundIsNegative() throws Exception {
        Delay.exponential(-1, 100, TimeUnit.MILLISECONDS, 10);
    }

    @Test(expected = IllegalArgumentException.class)
    public void shouldNotCreateIfLowerBoundIsSameAsUpperBound() throws Exception {
        Delay.exponential(100, 100, TimeUnit.MILLISECONDS, 10);
    }

    @Test(expected = IllegalArgumentException.class)
    public void shouldNotCreateIfPowerIsOne() throws Exception {
        Delay.exponential(100, 1000, TimeUnit.MILLISECONDS, 1);
    }

    @Test
    public void negativeAttemptShouldReturnZero() throws Exception {

        Delay delay = Delay.exponential();

        assertThat(delay.createDelay(-1)).isEqualTo(0);
    }

    @Test
    public void zeroShouldReturnZero() throws Exception {

        Delay delay = Delay.exponential();

        assertThat(delay.createDelay(0)).isEqualTo(0);
    }

    @Test
    public void testDefaultDelays() throws Exception {

        Delay delay = Delay.exponential();

        assertThat(delay.getTimeUnit()).isEqualTo(TimeUnit.MILLISECONDS);

        assertThat(delay.createDelay(1)).isEqualTo(1);
        assertThat(delay.createDelay(2)).isEqualTo(2);
        assertThat(delay.createDelay(3)).isEqualTo(4);
        assertThat(delay.createDelay(4)).isEqualTo(8);
        assertThat(delay.createDelay(5)).isEqualTo(16);
        assertThat(delay.createDelay(6)).isEqualTo(32);
        assertThat(delay.createDelay(7)).isEqualTo(64);
        assertThat(delay.createDelay(8)).isEqualTo(128);
        assertThat(delay.createDelay(9)).isEqualTo(256);
        assertThat(delay.createDelay(10)).isEqualTo(512);
        assertThat(delay.createDelay(11)).isEqualTo(1024);
        assertThat(delay.createDelay(12)).isEqualTo(2048);
        assertThat(delay.createDelay(13)).isEqualTo(4096);
        assertThat(delay.createDelay(14)).isEqualTo(8192);
        assertThat(delay.createDelay(15)).isEqualTo(16384);
        assertThat(delay.createDelay(16)).isEqualTo(30000);
        assertThat(delay.createDelay(17)).isEqualTo(30000);
        assertThat(delay.createDelay(Integer.MAX_VALUE)).isEqualTo(30000);
    }

    @Test
    public void testPow10Delays() throws Exception {

        Delay delay = Delay.exponential(100, 10000, TimeUnit.MILLISECONDS, 10);

        assertThat(delay.createDelay(1)).isEqualTo(100);
        assertThat(delay.createDelay(2)).isEqualTo(100);
        assertThat(delay.createDelay(3)).isEqualTo(100);
        assertThat(delay.createDelay(4)).isEqualTo(1000);
        assertThat(delay.createDelay(5)).isEqualTo(10000);
        assertThat(delay.createDelay(Integer.MAX_VALUE)).isEqualTo(10000);
    }
}