Selenium automatically accepting alerts

Just the other day i've answered something similar to this so it's still fresh. The reason your code is failing is if the alert is not shown by the time the code is processed it will mostly fail.

Thankfully, the guys from Selenium WebDriver have a wait already implemented for it. For your code is as simple as doing this:

String alertText = "";
WebDriverWait wait = new WebDriverWait(driver, 5);
// This will wait for a maximum of 5 seconds, everytime wait is used

driver.findElement(By.xpath("//button[text() = \"Edit\"]")).click();//causes page to alert() something

wait.until(ExpectedConditions.alertIsPresent());
// Before you try to switch to the so given alert, he needs to be present.

Alert alert = driver.switchTo().alert();
alertText = alert.getText();
alert.accept();

return alertText;

You can find all the API from ExpectedConditions here, and if you want the code behind this method here.

This code also solves the problem because you can't return alert.getText() after closing the alert, so i store in a variable for you.

Before you accept() the alert you need to get the text. What you're doing right now is accepting (clicking "OK") on the alert then trying to get the alerts text after it's out of the screen, i.e. no alert present.

Try the following, I just added a String that retrieves the alert text then return that string instead.

driver.findElement(By.xpath("//button[text() = \"Edit\"]")).click();//causes page to
Alert alert = driver.switchTo().alert();
String alertText = alert.getText();
alert.accept();
return alertText;