You're sharing a WebDriver instance across multiple threads. As such, one test can try to use the WebDriver after another test's afterMethod has already quit it (hence the session not found exception) or hasn't loaded google.com yet (hence the no such element exception).
If you want to run Selenium WebDriver tests using TestNG in parallel then you can use a ThreadLocal to maintain a WebDriver instance per thread.
e.g.
public class DemoTest {
private static final ThreadLocal<WebDriver> WEB_DRIVER_THREAD_LOCAL = new InheritableThreadLocal<>();
@Test(dataProvider = "dp")
public void f(Integer n, String s) {
WebDriver driver = WEB_DRIVER_THREAD_LOCAL.get();
System.out.println("Driver: " + driver.toString());
driver.get("www.google.com");
driver.findElement(By.id("lst-ib")).sendKeys("1234567");
System.out.println("method f id:" + Thread.currentThread().getId() + " n:" + n + " s:" + s);
}
@BeforeMethod
public void beforeMethod() {
WebDriver driver = new FirefoxDriver();
driver.manage().timeouts().implicitlyWait(10, TimeUnit.SECONDS);
driver.manage().window().maximize();
WEB_DRIVER_THREAD_LOCAL.set(driver);
System.out.println("Before method id:" + Thread.currentThread().getId());
}
@AfterMethod
public void afterMethod() {
WebDriver driver = WEB_DRIVER_THREAD_LOCAL.get();
System.out.println("After method id:" + Thread.currentThread().getId());
if (driver != null) {
driver.quit();
}
}
@DataProvider(parallel = true)
public Object[][] dp() {
return new Object[][]{
new Object[]{1, "a"},
new Object[]{2, "b"},
new Object[]{3, "c"},
new Object[]{4, "d"},
};
}
}
I've omitted wrapping each test with a try-catch block as TestNG already catches exceptions thrown by test/configuration methods and prints stack traces for them, etc.
The above example will create a WebDriver instance associated with the test's thread for each test. i.e. If they were to all run truly in parallel you would have 4 instances of Firefox open (which I think is what you want).
If you have more tests than threads and want to reuse WebDriver instances then you can use a ThreadLocal with an initial value.
e.g.
public class DemoTest {
private static final Set<WebDriver> WEB_DRIVERS = new HashSet<>();
private static final ThreadLocal<WebDriver> WEB_DRIVER_THREAD_LOCAL = InheritableThreadLocal
.withInitial(new Supplier<WebDriver>() {
@Override
public WebDriver get() {
WebDriver driver = new FirefoxDriver();
driver.manage().timeouts().implicitlyWait(10, TimeUnit.SECONDS);
driver.manage().window().maximize();
WEB_DRIVERS.add(driver);
System.out.println("Before thread id:" + Thread.currentThread().getId());
return driver;
}
});
@Test(dataProvider = "dp")
public void f(Integer n, String s) {
WebDriver driver = WEB_DRIVER_THREAD_LOCAL.get();
System.out.println("Driver: " + driver.toString());
driver.get("www.google.com");
driver.findElement(By.id("lst-ib")).sendKeys("1234567");
System.out.println("method f id:" + Thread.currentThread().getId() + " n:" + n + " s:" + s);
}
@AfterClass
public void afterClass() {
for (WebDriver webDriver : WEB_DRIVERS) {
try {
webDriver.quit();
} catch (Exception e) {
e.printStackTrace();
}
}
}
@DataProvider(parallel = true)
public Object[][] dp() {
return new Object[][]{
new Object[]{1, "a"},
new Object[]{2, "b"},
new Object[]{3, "c"},
new Object[]{4, "d"},
};
}
}
And a testng.xml to reduce the total number of threads to demonstrate this:
<suite name="Suite" parallel="methods" thread-count="2" data-provider-thread-count="2">
<test name="prelogin">
<classes>
<class name="DemoTest"/>
</classes>
</test>
</suite>
Example output (see how it only creates 2 FirefoxDriver instances, runs two tests in parallel, and then runs the next two tests in parallel, using all the available threads and reusing the web drivers for each thread):
Before thread id:14
Driver: FirefoxDriver: firefox on WINDOWS (e924b5f1-9ace-46e5-a6b3-d1494de7e94d)
method f id:14 n:2 s:b
Before thread id:13
Driver: FirefoxDriver: firefox on WINDOWS (8dc8a53c-5a96-41e8-9383-e552c7c8f680)
method f id:13 n:1 s:a
Driver: FirefoxDriver: firefox on WINDOWS (8dc8a53c-5a96-41e8-9383-e552c7c8f680)
method f id:13 n:3 s:c
Driver: FirefoxDriver: firefox on WINDOWS (8dc8a53c-5a96-41e8-9383-e552c7c8f680)
method f id:13 n:4 s:d
