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Monday, 8 July 2013

Test Automation - Object Identification


There are about 30 students in a class; you need to find out whether the person you want to talk to, is there or not; assume you have not seen him. You first go and ask "Is John here? I have a parcel to deliver". So, you use the first name to identify a person. If there are 2 Johns in the same class, then you will ask "John Bosco". So you use last name also as additional qualifier to uniquely identify that person, among 30 other students. As a rare case, if both are John Bosco, what will you do? You may say "John Bosco, son of  David P Bosco". The goal is to deliver the parcel to the right person. Testing tools also work on very similar way to carry out click or type actions, on the exact objects on the application UI.

If one has a very good grasp on object identification concepts, 80% of the automation problems are already solved. An object means an item on the user interface, on which you either click or type or you read it and infer some information; e.g. first name text box, state combo box, save button, etc. Recording feature in every tool, internally does this object identification. Most of the tools use a way of storing the details of objects in a separate file. In HP QTP it is called Object Repository, in IBM Rational Functional Tester it is called Object Map, in Borland SilkTest it is called frames.inc, and so on. 

Every object has a type, aka class. The most common types are text box, check button, radio button, combo box, push button, menu bar, tool bar, label, link, image, grid (rows, columns, cell), scroll bar, status bar, progress bar. These are the typical items we see in every application. But the exact way, every technology calls these classes will be different; for example, native Windows C++ will say Push Button, Java will say JButton, Turbo C++ may say TButton, for the same push button you see on screen. This specific text is called nativeclass. 

They also have a name associated with them. This is not mandatory, but preferable. The objects may display a name on screen for the user to read, but it may internally use another name. This is like the nick name we use for people. Tools understand the internal name of the objects, rather than the display name of the objects. Ideally developers of the screens must use same, meaningful names for display as well as internal purposes. 

The best way to identify an object is to use the type/class of the object and its internal name. e.g. button/OK, combobox/States, textbox/ZIP code etc. Sometimes, the same display name may appear 2 times on the UI. Consider a screen that takes your personal and office addresses; both will have street/city/state text boxes. So the display name is same; the humans understand this well; but for the tools to understand two objects with same display name, it is better to use the internal name given by developers. 

When we need additional details to uniquely identify an object, there are other properties such as location (x, y coordinates), index of the object (nth object from top of the screen) are usually used. But position based identification is a risky option; this may fail when screen is updated with new objects or a few objects are removed, that may affect the relative position of this field on the screen. 

To understand the objects and their properties, tools provide object spy or object inspector utilities. Before you start automating, spend a few hours to see the class, name and other properties of every object on every single screen. If you see objects with confusing properties or non-unique properties, negotiate with development team to have consistent naming of objects.

Remember: Proper naming of objects reduces the time to automate significantly. This simple process discipline is required by the dev team to make test automation is easy.

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