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Using WET for Web testing

Table of Contents

Using WET for Web testing 1

1 Introduction 3

2 Why Wet? 3

3 History and Evolution 3

4 Philosophy of WET 4

4.1 Philosophy explained: 6

5 Features / Components of WET 7

5 Testing process using WET 9

5.1 Plan and Organize tests 11

5.2 Use simulated browser to identify objects and create skeleton scripts 11

5.3 Create the basic test definition file 12

5.4 Complete the scripting using the WET API 12

5.5 Enhance and modularize scripts 12

5.6 Enhance the test definition files 12

5.7 Execute tests, analyze results and fix issues 13

6 Conclusion 13

1 Introduction

WET started off as add-on to the Watir Framework and is now a complete Web testing tool by itself although it still uses Watir as the library. WET provides many enhanced features and functions on top of Watir. WET classes inherit from Watir and therefore adds features without removing support for any of the existing feature.The features offered by WET in a nutshell are:

2 Why Wet?

WET is an opensource alternative to commercial and proprietory web testing tools. While WET provides you the freedom that comes built into opensource applications, it retains and in some cases surpasses all the features required by a web automation testing tool. WET was created by a team of expert testers who understand the needs of the testing community. As a result WET comes bundled with some very powerful capabilities that are required for a successful test automation project. WET uses the Proxied UI mechanism to create initial scripts, a concept that allows one to create test scripts with the same ease as in test recorders, but leaves out the issues that come bundled with recorders Finally, Commercial support for WET is available through Thwameva Technologies, which allows your enterprise to buy you peace of mind, while still enjoying all the benefits of opensource.

3 History and Evolution

WET started off as a small extension library for Watir – Watir Extension Toolkit. It has come a long way and is now bundled with many compelling features. As the codebase of WET has grown multiple times, it now uses Watir just as the library to drive IE. WET not only offers you all that Watir offers but many more powerful features to help make your test automation effort a success. With the increased features bundled into the code base, we no longer refer to WET as Watir Extension Toolkit. It is simply called as WET

WET's first release, 0.5 was made to the opensource community on 8th August 2005. In its first release, WET added a few features like Object repository (now rechristened as Object Depot), integrated data table support and slick HTML results. Besides this, WET retained the same philosophy as Watir – perform operations on an IE browser programmatically. WET provided a set of classes which was an extension of the Watir classes. These classes were exposed to the tester as the WET API. A tester could use all the classes from the Watir API directly as WET was nothing else but an extension of Watir

On October 2nd 2006, the final release of WET 0.9.8 was made. The WET 0.9.8 was a major improvement over the previous version. The philosophy of WET itself had a major shakeup with the introduction of the WET UI. Besides this, WET now started using Watir as a library rather than extending the classes, thus allowing WET to pack a lot more power in its hood.

In Mid 2007, WET 1.0 will be released (as of this writing which is on the 27th of May 2007, 1.0 is in its alpha stage) which again has some significant improvements when compared to verison 0.9.8 which will be covered in detail in subsequent sections and in various user guides. One of the most significant change in 1.0 when compared to 0.9.8 was to create new utilities which were meant to demythify a certain wrong message that we sent in WET 0.9.8. The WET UI was created to make certain parts of test development easier – for example, identification of objects and creation of the object depot. However thanks to the WET UI was trying to make things a bit more simpler than it should have – it started giving rise to the belief that the WET UI can be used to create end to end test automation scripts. Nothing can be farther from the truth. Test automation is a serious development like activity which requires its own skills and expertise. In WET 1.0 we have made an effort to correct this misconception by disintegrating the WET UI into different applications. To create WET Test suites, the tester can use the WET UI to identify html objects on the web page being tested, creating the object depot and creating the script skeletons. For the rest of the test automation activity, the tester has to hand-hold most of the activities.

4 Philosophy of WET

The use of test recorders in automation, is a concept that, of late has been advocated against by experts. Instead, they advice the use of scripting tests from the ground up. While recorders offer you a faster development time, scripting allows you to take full control of the application that you are trying to test. The latter obviously is a lot more tedious and time-consuming. WET allows you to take advantage of the best of both worlds.

The following illustration will help understand the limitations of recorders, strength of scripting and the advanatage of using WET. There are two broadly used techniques of creating test automation scripts – a) Record / playback and b) pure scripted. WET takes a middle approach between these taking advantage of the best that each of the technique offers:

1. Recorders:

2. Scripting :

3. WET UI :

Illustration 1: The various techniques used in test automation

4.1 Philosophy explained:

To understand the benefits and limitations of each process, let's see each one of them in detail:


There are inherent problems that are associated with this technique. To name a few:

Pure scripted :

To avoid problems seen in recorders, experts advice to totally throw away recorders and use a pure scripted solution from the scratch. Although this is a great technique, it can become extremely tedious to do some of the preliminary tasks like mapping all the test objects. If this has to be done by the tester, then one would have to go into the source of the page (assuming AUT is a web application), identify each tag and then map them to some mnemonic name. Clearly this is a very tedious process.

WET UI's technique :

The WET Script assistant utility offers an innovative solution that lies somewhere in between. We call this as the 'proxied UI' technique. Please note that this is not the same as test recorders that use a http proxy to record the http messages being sent to and from the system under test. WET is a true enduser simulation testing tool and does not use http as the testing mechanism. The script assistant UI comes with the convenience of records, while it overcomes some of their limitations. Using this technique, a skeleton of the scripts is created by executing the manual tests on a simulated browser. The simulated browser is a UI application that is similar to a web browser in its look and feel but works differently. Using this simulated browser you can connect to an IE browser that is already running on your system and recreate the view of the IE browser. The tester can then instruct this simulated browser to perform various operations – which is converted to test scripts. For example, imagine the same web page as the one discussed previously –

Observe the fundamental difference between this technique and the record-playback mechanism. In the record-playback mechanism, the recorder, based on the events, assumes that certain operations were performed and generates scripts accordingly. In the 'proxied UI' technique, the tester explicitly instructs which operations are to be recorded. The second advantage – Using the 'proxied UI' technique, there is a 'review' stage between the 'actual operation' and the 'intended operation'. The tester does not directly perform operations on the simulated browser. Instead, the tester first does a right-click and then chooses the operation. By virtue of this, the scripts generated are far more accurate when compared to a blind record-playback technique.

The proxied UI allows you to perform only a limited set of basic web operations like clicking links, setting text etc., That is the reason that we call the scripts generated by the proxied UI as skeleton scripts. The tester has to extend these skeleton scripts by writing additonal functionality using the WET API / ruby libraries to acheive complete test automation. Right from the beginning of the creation of the WET UI (and we still continue to ) , we would like to emphasise that the scripts generated by the Wet script assistant are NOT the final, ready to use automation suite. To achieve a high degree of automation, you will have to take advantage of the advanced abilities provided by WET and powerful scripting abilities of Ruby. WET does not want to share the platform with those vendors who make the claim that using a script generation tool can instantly convert a novice user into a test automation engineer. We only want to try and achieve these:

To summarize, WET is one of those tools which offers the convenience of recorders, without compromising on the requirements of a true test automation tool – the ability to take control of the application by using a powerful scripting / programming ability.

5 Features / Components of WET

WET can be broadly classified as consisting of two layers :

Wet Core :- This is the engine that drives automation using WET. The WET core is a library written using the Ruby scripting library. Ruby is a powerful object oriented scripting language and therefore WET itself has a great scripting ability. The WET library can be used to drive an Internet Explorer browser and perform various operations like clicking buttons, setting text, etc. on the IE browser.

Wet UI: Various UI utilities that assists the tester to create WET test suites. You may call these utilities as the front end UI for the various features of WET Core. The WET UI utilities have all been written using C#.

5.1 Wet Core

The WET core layer is like the heart of WET with regard to test automation. The core layer offers the following abilities:

API to control a web browser : The WET API is a ruby library using which various operations can be performed on an IE browser. For example, you can set some text on a textfield, turn on selected checkboxes, click buttons, etc., After this you can verify if the resulting pages displayed are as expected. This is nothing else but the same steps that you would be performing in a manual test scenario.

Object depot : When working with test automation, you typically end up writing tens of thousands of lines of test scripts. These scripts typically have operations that need to be performed on various objects (eg. html) of the application under test. Since many of these objects will be common across various pages of this application, there is a great deal of repitition which becomes a maintanance nightmare. To address this, WET uses an XML based object repository, called Object depot. using the Object depot, definitions about the different UI elements to be used in the application under test are stored in a centralized XML file.

Integrated Datatable support : There are many instances when the same test scripts have to be run against different data. For example, the test script to add 2 numbers will be the same but we may want to run it against different types of numbers. This can be acheived in WET by using the integrated support for Datatables that WET offers. Here, data is organized as rows and columns – The columns representing the fields and the rows representing the different categories of data. WET has support for three types of datatables – a) Excel data table – here WET can read directly from Excel spreadsheets which follow a specified format for the rows / columns, b) XMLdata table – In this case, the fields and categories are defined in an XML file that follows the presecribed xml schema and c) CSV Datatable – In this case the data is defined in a csv file with a pre-defined format. This feature allows users who dont use Microsoft Excel (eg. Openoffice users) to take advantage of datatables.

Test definitions : Test definition is a unique feature of WET, thanks to which tests can be defined in a robust manner. The test definition is a file which describes various artifacts of the test like the name of the test, description, which datatable file to use, which object depot file to use, how many preconditions does the test have?, how many teardowns?, what are the test steps of this test?, and so on. This allows a tester to define a WET test in exactly the same way that manual test cases are written.

Slick HTML Results : After WET tests have been completed, the results that are displayed have complete information about the test and is in HTML format. This allows the results to be shared with anybody – even those who dont have WET installed.

5.2 Wet UI

The WET UI is a collection of various UI utilities that assist the creation of scripts. Typically, each of the UI utility works as a front end for a corresponding WET core feature. The following are the various components of the WET UI:

WET Manager : As the name suggests, the WET manager is the control panel for all other WET UI applications. This control panel can be used to launch and manage each of the WET UI applications

Simulated IE : A proxied UI which looks just like an IE browser. Using this application, you can connect to an open IE browser and simulate various actions like button clicks. These actions are then performed on the real browser. These actions are also used to a) identify objects and generate the object depot file and b) generate WET script lines corresponding to the actions performed.

WET Simulated Browser : A proxied UI which has its own look and feel. Works just like the simulated IE in terms of object identifcation / script line generation but the view here is not same as the real IE browser.

Treeview browser : A proxied UI in which the elements of the 'connected' IE are displayed in the form of a treview. The treeview's hierarchy is the same as the DOM of the actual page being shown. Just like the simulated IE, the actions that are performed on the treeview are converted to object depots and script lines.

Object depot manager : The front-end UI for creating and managing object depot files. Using the object depot manager, you can either create object depots from the scratch or edit existing object depots.

Test definition editor : The front-end UI to create and edit test definitions. Unlike the previous version of WET(0.9.8), starting from version 1.0 onwards, the test definition editor is more of a 'dumb' editor. You can only define values for various parameters using the test definition editor. The underlying changes are not taken care of automatically. For example, if you define a value for the precondition and the precondition does not exist, then WET does not try to create the precondition for you automatically.

Script Editor : A basic editor to edit and create WET test scripts.

Dynamic configuration editor : WET uses a configuration file to control certain parameters. The values in the configuration file is the value that is used as the default. However in some cases, it may be required to use a value different from the default value. The dynamic configuration editor allows you to do this. Again not all configuration parameters can be changed – only a couple of parameters can be edited using the dynamic configuration editor.

The above sections are a brief overview about each of the WET components. Detailed description about each of the above components can be found in individual user guides.

5 Testing process using WET

The process of creating test automation suites using WET is a multi stage process which involves quite a few steps. To derive the best out of the powerful abilities of WET, it is suggested at the minimum, that all the steps mentioned below are followed. The section below is just an overview of the steps required for creating WET test suites. Individual user guides of different components will provide a more detailed description of these steps.

The illustration below gives a graphical overview of the steps involved in creating wet test suites.

Illustration 2: Flowchart of the testing process using WET


5.1 Plan and Organize tests

As in any activity, planning is a critical phase of test automation. This should be your first step before starting any other activity. The various aspects to consider while planning are:

Once you have taken care of these planning items, then you will need to come up with a folder structure to organize your entire test suite. Organize your folders well helps a lot in making sure that tests run more reliably. Although the folder structure that you choose entirely depends on your application and your preferences, the following is a suggestion (One that we use as the baseline for all our tests)


tests/ (the tests folder is where all the wet tests will be saved)


|- test.defs


|- $trans1.wet

|- $trans2.wet

|- ....

|- $transn.wet

|-results |

|- (test will

| create results)

|- data -|

|- data.xls

$test_name2-- //Have same structure as above...

//and you could have any number of tests like

//$test_name3, etc.

libs/ (place for precondition / teardown tests)

$lib_test1 --|- test.defs


|- $trans1.wet

|- $trans2.wet

repository/ (place for object depot)



ruby_libs/ (place for customized ruby libraries)



5.2 Use simulated browser to identify objects and create skeleton scripts

Now that you have planned the scenarios that have to be automated, you can start creating the scripts skeleton and the object depot. The simulated browser helps in both these activities. Although you are free to choose whichever simulated browser suits you the most (Simulated IE, Wet Simulated browser or Wet treeview), we recommend the usage of the Wet Treeview as the most reliable one.

Once the script skeletons and the object depot have been created, then save the scripts and the object depot to the appropriate locations

Tips :

  • If you are planning to use a common object depot file for various scripts, then you should first open this object depot file and associate your simulated browser with this object depot manager

  • In case you are using the same object depot in most of your scenarios then consider setting the object_depot parameter in the WetUI.cfg:
    object_depot= <path_to_your_commonly_used_object_depot>

5.3 Create the basic test definition file

Using the test definition editor, create the basic test definition file. In this basic test definition file, the object definition path and the transaction script have to be added. This will allow easy testing of the developed scripts before enhancing the scripts further. After the test scripts have been further enhanced and other modularizing techniques applied, you'll have to come back and modify the test definitions further to set the datatable path, add preconditons, add teardowns and add additional transactions if required.

5.4 Complete the scripting using the WET API

As mentioned earlier, scripts generated using the simulated browser can only be considered to be a 'skeleton' or 'placeholder' scripts. This will not exploit the full power of what WET has to offer. To exploit this, you will have to enhance the scripts by hand using the WET API library refrerence as a guide.

5.5 Enhance and modularize scripts

To increase the test coverage and to improve the reliability of scripts, tests should be modularized. The techniques used in this area are:

Parametrize tests and use datatables :- The use of datatables allows the same test script to be easily reused against multiple data inputs. These data inputs are specified in either a excel datasheet, an xml file or in a csv format. To allow a script to use datatables, these scripts must be designed such that they can accept parameters.

Parametrize and customize object depot :- WET's object depot has some pretty powerful features. A couple of them are a) The attribute value can be defined as a regular expression instead of a string literal. b) The object depot itself can be parametrized – that is, can be designed to accept parameters at run time. This feature is very handy when you want to write scripts for those pages in which the elements change at runtime based on the input passed. (For example, the number of messages in the inbox depends on how many messages were deposited). The simulated browser, while creating object depots automatically, cannot take advantage of these advanced features. This customization has to be done manually by the tester.

Write specialized ruby libraries :- WET is written in ruby, which is a full-fledged Object oriented scripting language. A tester can write specialized libraries using Ruby and plug them into the Wet test suite. These ruby libraries are typically used to move beyond 'gui automation' so that the test scripts can also verify other reactions (for ex. checking database or checking the backend file system, etc.)

5.6 Enhance the test definition files

The test definitions created in step 5.3 was a bare bones test definition which wasn't taking the full advantage of the powerful features offered by WET. After completing the test script enhancement and modularization of object depot / parametrization, you should now go back and edit the test definition so that these advanced features are harnessed. The test definition enhancements that can be done are:

5.7 Execute tests, analyze results and fix issues

Test automation is just like any development activity. The final step, therefore, would be to execute the developed test scripts and run them against the application under test. After running these tests, analyze the results and based on the results either fix issues, if any, or if required, make enhancements to the tests.

6 Conclusion

This user guide provides an insight into WET and the process of test automation using WET. This is not supposed to be a detailed guide for web testing using WET. For a more detailed explanation about each of the features, refer to the individual user guide for that feature.


WET is a opensource automated web testing tool which uses Watir as the library to drive web pages. WET drives an IE Browser directly and so the automated testing done using WET is equivalent to how a user would drive the web pages. WET extends the scripting abilities of Watir and also offers the convenience of recorders. It is licensed under LGPL and BSD style open source licenses.

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