Selenium Basics

Getting Started – Choosing Your Selenium Tool

Most people get started with Selenium-IDE. This is what we recommend. It’s an easy way to get familiar with Selenium commands quickly. You can develop your first script in just a few minutes. Selenium-IDE is also very easy to install. See the chapter on Selenium-IDE for specifics.

You may also run your scripts from the Selenium-IDE. It’s simple to use and is recommended for less-technical users. The IDE allows developing and running tests without the need for programming skills as required by Selenium-RC. The Selenium-IDE can serve as an excellent way to train junior-level employees in test automation. Anyone who understands how to conduct manual testing of a website can easily transition to using the Selenium-IDE for running and developing tests.

Some testing tasks are too complex though for the Selenium-IDE. When programming logic is required Selenium-RC must be used. For example, any tests requiring iteration, such as testing each element of a variable length list requires running the script from a programming language. Selenium-IDE does not support iteration or condition statements.

Finally, Selenium-Core is another way of running tests. One can run test scripts from a web-browser using the HTML interface TestRunner.html. This is the original method for running Selenium commands. It has limitations though; similar to Selenium-IDE, it does not support iteration.

Selenium-Core also cannot switch between http and https protocols. Since the development of Selenium-IDE and Selenium-RC, more people are using these tools rather than Selenium-Core. At the time of writing (April 09) it is still available and may be convenient for some. However, the Selenium community is encouraging the use of Selenium-IDE and RC and discouraging the use of Selenium-Core. Support for Selenium-Core is becoming less available and it may even be deprecated in a future release.

Introducing Selenium Commands

Selenium Commands – Selenese

Selenium provides a rich set of commands for fully testing your web-app in virtually any way you can imagine. The command set is often called selenese. These commands essentially create a testing language.

In selenese, one can test the existence of UI elements based on their HTML tags, test for specific content, test for broken links, input fields, selection list options, submitting forms, and table data among other things. In addition Selenium commands support testing of window size, mouse position, alerts, Ajax functionality, pop up windows, event handling, and many other web-application features. The Command Reference lists all the available commands.

A command is what tells Selenium what to do. Selenium commands come in three “flavors”: Actions, Accessors and Assertions.

• Actions are commands that generally manipulate the state of the application. They do things like “click this link” and “select that option”. If an Action fails, or has an error, the execution of the current test is stopped.

  Many Actions can be called with the “AndWait” suffix, e.g. “clickAndWait”. This suffix tells Selenium that the action will cause the browser to make a call to the server, and that Selenium should wait for a new page to load.

• Accessors examine the state of the application and store the results in variables, e.g. “storeTitle”. They are also used to automatically generate Assertions.

• Assertions are like Accessors, but they verify that the state of the application conforms to what is expected. Examples include “make sure the page title is X” and “verify that this checkbox is checked”.

  All Selenium Assertions can be used in 3 modes: “assert”, “verify”, and ” waitFor”. For example, you can “assertText”, “verifyText” and “waitForText”. When an “assert” fails, the test is aborted. When a “verify” fails, the test will continue execution, logging the failure. This allows a single “assert” to ensure that the application is on the correct page, followed by a bunch of “verify” assertions to test form field values, labels, etc.

  “waitFor” commands wait for some condition to become true (which can be useful for testing Ajax applications). They will succeed immediately if the condition is already true. However, they will fail and halt the test if the condition does not become true within the current timeout setting (see the setTimeout action below).

Script Syntax

Selenium commands are simple, they consist of the command and two parameters. For example:

verifyText

//div//a[2]

Login

The parameters are not always required; it depends on the command. In some cases both are required, in others one parameter is required, and in still others the command may take no parameters at all. Here are a couple more examples:

goBackAndWait
verifyTextPresent		Welcome to My Home Page
type	id=phone	(555) 666-7066
type	id=address1	${myVariableAddress}

The command reference describes the parameter requirements for each command.

Parameters vary, however they are typically:

• a locator for identifying a UI element within a page.
• a text pattern for verifying or asserting expected page content
• a text pattern or a selenium variable for entering text in an input field or for selecting an option from an option list.

Locators, text patterns, selenium variables, and the commands themselves are described in considerable detail in the section on Selenium Commands.

Selenium scripts that will be run from Selenium-IDE will be be stored in an HTML text file format. This consists of an HTML table with three columns. The first column identifies the Selenium command, the second is a target, and the final column contains a value. The second and third columns may not require values depending on the chosen Selenium command, but they should be present. Each table row represents a new Selenium command. Here is an example of a test that opens a page, asserts the page title and then verifies some content on the page:

<table>
    <tr><td>open</td><td></td><td>/download/</td></tr>
    <tr><td>assertTitle</td><td></td><td>Downloads</td></tr>
    <tr><td>verifyText</td><td>//h2</td><td>Downloads</td></tr>
</table>

Rendered as a table in a browser this would look like the following:

open		/download/
assertTitle		Downloads
verifyText	//h2	Downloads

The Selenese HTML syntax can be used to write and run tests without requiring knowledge of a programming language. With a basic knowledge of selenese and Selenium-IDE you can quickly produce and run testcases.

Test Suites

A test suite is a collection of tests. Often one will run all the tests in a test suite as one continuous batch-job.

When using Selenium-IDE, test suites also can be defined using a simple HTML file. The syntax again is simple. An HTML table defines a list of tests where each row defines the filesystem path to each test. An example tells it all.

<html>
<head>
<title>Test Suite Function Tests - Priority 1</title>
</head>
<body>
<table>
  <tr><td><b>Suite Of Tests</b></td></tr>
  <tr><td><a href="./Login.html">Login</a></td></tr>
  <tr><td><a href="./SearchValues.html">Test Searching for Values</a></td></tr>
  <tr><td><a href="./SaveValues.html">Test Save</a></td></tr>
</table>
</body>
</html>

A file similar to this would allow running the tests all at once, one after another, from the Selenium-IDE.

Test suites can also be maintained when using Selenium-RC. This is done via programming and can be done a number of ways. Commonly Junit is used to maintain a test suite if one is using Selenium-RC with Java. Additionally, if C# is the chosen language, Nunit could be employed. If using an interpreted language like Python with Selenium-RC than some simple programming would be involved in setting up a test suite. Since the whole reason for using Sel-RC is to make use of programming logic for your testing this usually isn’t a problem.

Commonly Used Selenium Commands

To conclude our introduction of Selenium, we’ll show you a few typical Selenium commands. These are probably the most commonly used commands for building tests.

open

opens a page using a URL.

click/clickAndWait

performs a click operation, and optionally waits for a new page to load.

verifyTitle/assertTitle

verifies an expected page title.

verifyTextPresent

verifies expected text is somewhere on the page.

verifyElementPresent

verifies an expected UI element, as defined by its HTML tag, is present on the page.

verifyText

verifies expected text and it’s corresponding HTML tag are present on the page.

verifyTable

verifies a table’s expected contents.

waitForPageToLoad

pauses execution until an expected new page loads. Called automatically when clickAndWait is used.

waitForElementPresent

pauses execution until an expected UI element, as defined by its HTML tag, is present on the page.

Summary

Now that you’ve seen an introduction to Selenium, you’re ready to start writing your first scripts. We recommend beginning with the Selenium IDE and its context-sensitive, right-click, menu. This will allow you to get familiar with the most common Selenium commands quickly, and you can have a simple script done in just a minute or two. Chapter 3 gets you started and then guides you through all the features of the Selenium-IDE.