-
Overview
-Driven Selenium is where the browser is under the the control of an
-adjacent process. That process is either a Java, .Net, Ruby or Python
-application and it is typically run in conjunction with a unit testing
-framework like JUnit or NUnit. Also possible, is a console application
-driving a browser interactively.
-
Selenium & Selenese
-The key to this mode of operation is manner in which the browset-bot
-takes instruction from the driver. If it were possible, the
-browser-bot's javascript would open a server socket and await requests
-from the driver. It is against the rules for browser embedded
-javascript, to open ports for incoking requests as it would be a
-general breach of security for the client-OS that the browser is
-running on. What a browser can do is open addition requests to
-the same server that its source came from. See
http://www.mozilla.org/projects/security/components/same-origin.html
-for more info.
-
-To overcome the limitations of Javascript in a browser page is the page
-continuously requests pages from the driver (which has conveniently
-opened a web server). The pages which are retrieved from the server are
-in fact plain text and each is an individual instruction from the
-driver for what the browser-bot is to do next. E.g. -
-
- | open | /foo/bar.html | |
-
-We refer to this architecture are reply/request rather than the more
-ususal request/reply.
-
-The test script is one that would be recognisable to people adept with
-unit test frameworks :
-
-For Java -
-
- public void testOKClick() {
- selenium.verifyTitle("First Page");
- selenium.open("/TestPage.html");
- selenium.click("OKButton");
- selenium.verifyTitle("Another Page");
- }
-
-The difference from normal unit testing is that as part of the startup,
-three major things have to happen:
-
- - The test framework needs to publish a fresh copy of the
-Application Under Test (AUT).
-Selenium prefers to mount its own web server temporarily for the
-purposes of testing.
- - The test framework needs to publish the static Selenium pages
-(refer selenium dir in TestRunner mode above) in an apparent directory
-on the same web server as (1).
- - The test framework needs to open a browser instance and point it
-to Selenium.html served in (2) above.
-
-As each of these isa fairly time consuming operation, it is best that
-all three of those happen in a one time setup mode. As such, and
-even though these leverage a unit testing framework, this is definately
-for acceptance or functional testing.
-
Example Setup
-
-
For Java -
-
- selenium = new DefaultSelenium("c:\foo\bar-web-app\");
-
-The above will instantiate a web server using
Jetty, and
-publish it at http://localhost:8080. The Selenium pages will appear to
-be run from http://localhost:8080/selenium-driver. The default browser
-for Windows, Linux or Mac will be instantiated and directed to accept
-test instructions from the driver.
-
-The above would ususally be done in a setup method if under unit test
-control. See
http://junit.sourceforge.net/doc/faq/faq.htm#organize_3
-for advice on one time setup for Java.
-
-A more complex case could be -
-
- selenium = new DefaultSelenium(new
-TomcatCommandProcessor("c:\foo\bar-web-app"), new
-MyOperaBrowserLauncher()),
-
Command Reference
- void chooseCancelOnNextConfirmation();
- void click(String field);
- void clickAndWait(String field);
- void open(String path);
- void pause(int duration);
- void selectAndWait(String field, String value);
- void selectWindow(String window);
- void setTextField(String field, String value);
- void storeText(String element, String value);
- void storeValue(String field, String value);
- void testComplete();
- void type(String field, String value);
- void typeAndWait(String field, String value);
- void verifyAlert(String alert);
- void verifyAttribute(String element, String value);
- void verifyConfirmation(String confirmation);
- void verifyElementNotPresent(String type);
- void verifyElementPresent(String type);
- void verifyLocation(String location);
- void verifySelectOptions(String field, String[]
-values);
- void verifySelected(String field, String value);
- void verifyTable(String table, String value);
- void verifyText(String type, String text);
- void verifyTextPresent(String type, String text);
- void verifyTitle(String title);
- void verifyValue(String field, String value);
-
Deployment Choices
-
Embedded Web Server
-
-
-The best way to deply the driven form of Selenium is where an embedded
-web server is used. With the Java version, this could be Jetty or Tomcat.
-
-In advance of a series of selenese instructions being issued to the
-browser, a web server containing the AUT and some static pages for
-Selenium itself will be programmatically started and used to
-communicate selenese instructions to the browser. When the driver
-process is complete the web server will be programmatically stopped.
-
-
[ For release 0.2 - this is the only
-mode that really works. Those below will be fine for 0.3 and above ]
-
-
Adjacent Web Server
-
-By adjacent we mean a process on the same machine as the driver. As
-such it would appear as localhost to browsers.
-
-For the .Net driver embedded is very unlikely as Internet Information
-Server is running in its own process. For the Java driver, this could
-simple be a necessary choice - i.e. the deployment target is WebLogic
-or
-WebSphere which are not too embeddable.
-
-In this scenario we suggest you deploy a small web-app alongside the
-AUT that will liase between the driver process and the browser. Of
-course, there is less fine grained control over the starting and
-stopping of the server and indeed the version of the AUT. If the web
-server supports it, it is best to copy a fresh version of the AUT to
-the underlying directory that the web-app is mapped to. We call the
-small web-app the selenese proxy. It does of course slow things down a
-fraction.
-
-Selenese-proxy
-
-If you can deploy a copy of the selenese proxy to remote web server,
-and configure it to forward requests to your machine, then you can
-essentially script that remote web app. The downside of this is that
-that remote machine can essentially only be driven from the machine
-that is configured to drive it. i.e. it would need to be reconfigured
-to be driven from elsewhere. The upside is that you can to a great
-extent mix and match your technologies to achieve this proxying (a Java
-driver could use a Python selenese-proxy script a web-app).
-
Nearby Web Server
-
-This is where the AUT is running on a nearby testing stack or dedicated
-development box (not the developer's own workstation).
-
-To achieve this the selenese proxy needs to be deployed again, this
-time to that nearby machine. It will need to be reconfigured to
-indicate that selenese traffic is either forwarded to a particular
-machine.
-
-
Remote Web Server
-
-This is where the AUT is running on a remote machine, which you have no
-control over. A good example would be www.google.com. It is
-worth pointing out that this is of more interest to hackers or data
-harvesters than testing professionals, as what self respecting
-development group would prevent you from deploying at least the
-Selenese Proxy webapp to a testing stack.
-
-Funnel
-
-We are writing an application called the funnel that can help us
-overcome the
same
-origin issue that is key to Selenium. It essentially makes a
-selenium-driver/ directory appear on a remote web site for the purposes
-of the browser.
-
-
-