Using watir-webdriver, I am trying to set the value for a text field.
browser.text_field(:id, \"phoneNumbers_value_input\").set(\"5555551234\")
The problem has to do with focusing on the text field. Even with a .click() somehow webdriver ends up with the cursor at the end if the input field (see issue 2377). Pressing the HOME key moves the cursor to the beginning and allows you to type in the input field, and still have the mask functionality.
In Java:
WebElement txtPhone = getDriver().findElement(By.id("phoneNumbers_value_input"));
txtPhone.sendKeys(org.openqa.selenium.Keys.HOME);
txtPhone.sendKeys(phoneNumber);