Shows a possible bug in selenium-java: looks like there exists a weird inter-dependency between explicit and implicit wait

ImplicitVsExplicitWaitTest.java

import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.TimeUnit;

import org.openqa.selenium.By;
import org.openqa.selenium.TimeoutException;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.chrome.ChromeDriver;
import org.openqa.selenium.firefox.FirefoxDriver;
import org.openqa.selenium.support.ui.ExpectedCondition;
import org.openqa.selenium.support.ui.ExpectedConditions;
import org.openqa.selenium.support.ui.WebDriverWait;



public class Main {

	public static void main(String[] args) {
		List<int[]> data = new ArrayList<>();
		// each tuple = (explicit_timeout, implicit_timeout)
		data.add(new int[] {27, 27});	// => 27
		data.add(new int[] {16, 52});	// => 52
		data.add(new int[] {52, 16});	// => 65 <-- weird
		data.add(new int[] {12, 4});	// => 13 <-- weird
		data.add(new int[] {61, 29});	// => 88 <-- weird
				
		Main main = new Main();
		System.out.println("explicitWaitTimeout ; implicitWaitTimeout ; actualTimeout");
		System.out.println("Testing on CHROME");
		for(int[] tuple : data) { 
			main.implicitVsExplicitWaitTest(
					new ChromeDriver(), tuple[0], tuple[1]);
		}
		System.out.println("Testing on FIREFOX");
		for(int[] tuple : data) {
			main.implicitVsExplicitWaitTest(
				new FirefoxDriver(), tuple[0], tuple[1]);
		}
		System.exit(0);
	}

	private void implicitVsExplicitWaitTest(WebDriver driver, long explicitWaitTimeout, long implicitWaitTimeout) {
		int actualTimeout = 0;
		// set implicit wait
		driver.manage().timeouts().implicitlyWait(implicitWaitTimeout, TimeUnit.SECONDS);
		Clock clock = null;
		try {
			driver.get("http://www.google.it");
			clock = new Clock();
			clock.start();
			waitUntil(
				ExpectedConditions.visibilityOfElementLocated(By.cssSelector("#asd")),
				driver,
				// set explicit wait
				explicitWaitTimeout
			);
		} catch(TimeoutException e) {
			actualTimeout = clock.getAndStop();
		} finally {
			System.out.println(explicitWaitTimeout + ";" + implicitWaitTimeout + ";" + actualTimeout);
			driver.quit();
			clock.interrupt();
		}
	}
	
	public class Clock extends Thread {
		
		private int secondsPassed = 0;

		@Override
		public void run() {
			while(true) {
				try {
					Thread.sleep(1000);
					secondsPassed++;
				} catch (InterruptedException e) {
					System.out.println("clock was stopped");
				}
			}
		}
		
		/**
		 * @return how many seconds passed since this clock was started
		 */
		public int getAndStop() {
			interrupt();
			return secondsPassed;
		}
		
	}
	

	/**
	 * Generic explicit wait, taking an {@link ExpectedCondition} as a parameter.
	 * Times out after the given number of seconds.
	 *  
	 * @param expectedCondition
	 * @param driver
	 * @param timeOutInSeconds
	 * @see WebDriverWait#until(com.google.common.base.Function)
	 * @throws TimeoutException if the timeout expires
	 */
	public static void waitUntil(ExpectedCondition<?> expectedCondition,
			WebDriver driver, long timeOutInSeconds) {
		new WebDriverWait(driver, timeOutInSeconds)
			.until(expectedCondition);
	}
}