Testing (Part 2)

In the previous post, we've looked at what to test. Now it's time to see how to test. There are several different aspects:

• Regression Testing - Here, we test the result of current test with its previous results. This ensures that the bugs we fixed today didn't break the things that were working yesterday.
• Test data - There are two types of test data: real world data and synthetic data. Both are important, because each of these tests different aspects and behaviour of the system.
• Exercising GUI Systems - Testing GUI required special testing tools. Some of them record the events and play whenever required, while some others are based on a script. Writing code that is decoupled from GUI helps us to write better tests, because we can test the backend without interacting with the GUI.
• Testing the Tests - How do we test the tests? The easiest way is to introduce bugs intentionally in the tests and see if they complain. 
• Testing Thoroughly - How do we know if we have tested our code thoroughtly? The answer is we don't, and we never will. But we can use coverage analysis tools to keep track of it.

- summary of Ruthless Testing, from The Pragmatic Programmer: from Journeyman to Master 

Testing (Part 1)

Generally, developers hate testing. They hate to see their code breaking.

But we don't. We test every bits and pieces in our code. Why? Because we know that this is one place where we can see Butterfly effect in action! One simple mistake can cause large (and very bad, of course) effects in the future.

Test Early, Test Often, Test Automatically

Many teams develop elaborate test plans for their project. But automated tests, which run with every build is far better and successful than test plans that sit on a shelf. The earlier we find the bug, the easier the fix. In fact, a good project may have more test code than production code.

Just writing tests is not enough. We have to make sure that we run that often. We cannot say that coding is done unless all the tests are passing. These are some major types of test we need to perform:

• Unit Testing - Tests a module. Because if the module can't work alone, it cannot work with others as well.
• Integration Testing - Tests how the subsystems play and interact with each other.
• Validation and Verification - Ensures that what is build is what the user needs. Checks the functional requirements.
• Resource Exhaustion, Errors and Recovery - Tests how the system behaves in real world conditions under varying factors like memory, CPU bandwidth etc.
• Performance Testing - Stress testing, in which we tests our system and how it behaves when there is heavy load.
• Usability Testing - Different from all the above tests. Here we test the system with real users. It helps us to know how easy it is for them to use it.

- summary of Ruthless Testing, from The Pragmatic Programmer: from Journeyman to Master

Automation

When the first Model-T car was released, the instructions for starting the car were two pages long! Creeppy!! We get irritated if the car takes more than 5 seconds to start when we turn the key. A great example to show how we realised the importance of automation over the course of time.

Why do we need automation? It ensures consistency and repeatability. Manual procedures ensure consistency up to an extend, but not always repeatability. Because the interpretation varies slightly for different people. People are not repeatable as computers are.

Many tools are available for handling repeated tasks. One such example is cron. It allows us to schedule tasks to run periodically. We use cron to automatically backup data everyday at midnight, or to generate reports at the end of every month. We use makefiles to compile projects. It runs all the tests before build and compiles the project automatically with a single command.

Another great example is build automation. We use Continuous Integration Servers to deploy code to production servers. We use API doc generators to generate documentation automatically from source code.

Automation is inevitable. Let the computer do all the repetitive, mundane tasks. We've got better things to do...


- summary of Ubiquitous Automation, from The Pragmatic Programmer: from Journeyman to Master

Pragmatic Teams (Part 2)

Orthogonality

Traditional team organization is based on the waterfall model. The team includes individuals who are assigned roles based on different job functions. This is more strict in some cases, where one set of people are not allowed to talk to another!

This is a great mistake. It is a misconception that different aspects of development such as analysis, design, coding and testing can happen in isolation. The decisions taken in such cases may not be accurate.

Organize Around Functionality, Not Job Functions

Dividing based on functionality favours in many ways. When there customer wants to change the database, only one team gets affected. The sense of ownership increases when the team is aware of the fact that only they are responsible for that functional aspect.

Automation

A great way to achieve consistency and accuracy. Why do all the work manually when your editor can do a lot of things for you? Automation is an essential part of every process. We'll discuss about that in detail in the coming section


- summary of Pragmatic Teams, from The Pragmatic Programmer: from Journeyman to Master

Pragmatic Teams (Part 1)

So far, we have seen so many techniques that can help you as a better individual. But the value and outcome of these techniques are multiplied manyfold if you are working in a pragmatic team. Here are some of those techniques we already discussed in terms of teams:

No Broken Windows

Remember the broken window which you were too lazy to fix? It can happen to teams also. It is difficult for a pragmatic programmer if she joins a team which doesn't care about the quality. Some teams apply a quality manager, to take care of the issues. This is absolutely ridiculous! Pragmatic teams know that quality is the result of contributions from each and every member in the team.

Boiled Frogs

You might as well remember the frog which doesn't notice the gradual change in the water and ends up cooked. Being concious and mindful about all the varying aspects is not always easy, even for a team. Sometimes occurs from the assumption that someone else is already looking into the issue.

Fight this. Make sure that everyone monitors the change. If not, appoint a chief water tester, who constantly checks for variations. It is not necessary that you have to reject the change. At least, you should be aware of it.

Communicate

Good teams communicate well! Customers love to talk to such teams because their meetings are well organized. Discussions are live and the team speaks with one voice.

Don't Repeat Yourself

Chances of duplication is more in a team. A good project librarian can help in such situations. If a team member is looking for something, she must know that she has to talk to this person first. What if the project is too large for one person to handle? Divide it based on functional aspects so that one person can handle one particular aspect of the entire project.


- summary of Pragmatic Teams, from The Pragmatic Programmer: from Journeyman to Master.