[js] Add support for the alert credentials

Author: jleyba

javascript/node/selenium-webdriver/CHANGES.md

@@ -21,6 +21,8 @@
    The top-level `error` module will be removed in v3.0.
 * Moved `until.Condition` and `until.WebElementCondition` to the webdriver
    module to break a circular dependency.
+* Added support for setting the username and password in basic auth pop-up
+   dialogs (currently IE only).
 * FIXED: `io.findInPath()` will no longer match against directories that have
    the same basename as the target file.
 * FIXED: `phantomjs.Driver` now takes a third argument that defines the path to

javascript/node/selenium-webdriver/http/index.js

@@ -189,6 +189,7 @@ const COMMAND_MAP = new Map([
     [cmd.Name.DISMISS_ALERT, post('/session/:sessionId/dismiss_alert')],
     [cmd.Name.GET_ALERT_TEXT, get('/session/:sessionId/alert_text')],
     [cmd.Name.SET_ALERT_TEXT, post('/session/:sessionId/alert_text')],
+    [cmd.Name.SET_ALERT_CREDENTIALS, post('/session/:sessionId/alert/credentials')],
     [cmd.Name.GET_LOG, post('/session/:sessionId/log')],
     [cmd.Name.GET_AVAILABLE_LOG_TYPES, get('/session/:sessionId/log/types')],
     [cmd.Name.GET_SESSION_LOGS, post('/logs')],

javascript/node/selenium-webdriver/lib/command.js

@@ -159,6 +159,7 @@ const Name = {
   DISMISS_ALERT: 'dismissAlert',
   GET_ALERT_TEXT: 'getAlertText',
   SET_ALERT_TEXT: 'setAlertValue',
+  SET_ALERT_CREDENTIALS: 'setAlertCredentials',
 
   EXECUTE_SQL: 'executeSQL',
   GET_LOCATION: 'getLocation',

javascript/node/selenium-webdriver/lib/webdriver.js

@@ -2253,6 +2253,23 @@ class Alert {
     return this.text_;
   }
 
+  /**
+   * Sets the username and password in an alert prompting for credentials (such
+   * as a Basic HTTP Auth prompt). This method will implicitly
+   * {@linkplain #accept() submit} the dialog.
+   *
+   * @param {string} username The username to send.
+   * @param {string} password The password to send.
+   * @return {!promise.Promise<void>} A promise that will be resolved when this
+   *     command has completed.
+   */
+  authenticateAs(username, password) {
+    return this.driver_.schedule(
+        new command.Command(command.Name.SET_ALERT_CREDENTIALS),
+        'WebDriver.switchTo().alert()'
+            + `.authenticateAs("${username}", "${password}")`);
+  }
+
   /**
    * Accepts this alert.
    *
@@ -2347,6 +2364,16 @@ class AlertPromise extends Alert {
       });
     };
 
+    /**
+     * Defers action until the alert has been located.
+     * @override
+     */
+    this.authenticateAs = function(username, password) {
+      return alert.then(function(alert) {
+        return alert.authenticateAs(username, password);
+      });
+    };
+
     /**
      * Defers action until the alert has been located.
      * @override