Does Selenium implicit wait always take the entire wait time or can it finish sooner?

Question

Does Selenium implicit wait always take the entire wait time or can it finish sooner? If I set the implicit wait to 10 seconds, could a call to .findElement finish in a few

Answer 1

To my knowledge polling period is not 0.5 seconds with implicit wait. It is the case with explicit wait. Explicit wait polls the DOM every 500ms. Implicit wait, if the element is not found on page load waits for the specified time and then checks again after time is run out. If not found it throws an error

Answer 2

It can finish once it was able to find the element. If not it does throws the error and stops. The poll time is again very specific to the driver implementation ( not Java bindings , but the driver part, example: FireFox extension, Safari Extension etc.)

As I have mentioned here, these are very specific to the driver implementation. All driver related calls goes via execute method.

I'm putting up the gist over of the execute method (you can find the full source here):

protected Response execute(String driverCommand, Map<String, ?> parameters) {
    Command command = new Command(sessionId, driverCommand, parameters);
    Response response;

    long start = System.currentTimeMillis();
    String currentName = Thread.currentThread().getName();
    Thread.currentThread().setName(
        String.format("Forwarding %s on session %s to remote", driverCommand, sessionId));
    try {
      log(sessionId, command.getName(), command, When.BEFORE);
      response = executor.execute(command);
      log(sessionId, command.getName(), command, When.AFTER);

      if (response == null) {
        return null;
      }
      //other codes 
}

The line:

response = executor.execute(command);

says the whole story. executor is of type CommandExecutor, so all calls goes to the specific driver class like ChromeCommandExecutor,SafariDriverCommandExecutor, which has their own handling.

So the polling is upto the driver implementation.

If you want to specify the polling time, then you should probably start using Explicit Waits.

Answer 3

As mentioned the code comment:

 * When searching for a single element, the driver should poll the page until the 
 * element has been found, or this timeout expires before throwing a 
 * {@link NoSuchElementException}.

Its going to wait till that element present, or timeout occurs.

For example, If you set Implicit wait as 10 seconds, .findElement is going to wait maximum of 10 seconds for that element. Suppose that element available in the DOM in 5 seconds, then it will come out of "wait" and start executing next step.

Hope this clarifies.