Releasing software products without using automated testing is like writing code without using a compiler. Sure you can do it but it’s time consuming and error prone. Automated testing is something you should definitely keep in your toolbox, it aids in both system level and regression testing, and once it’s in place it’s trivial to run repeatedly. Here are six benefits of automated testing that will convince you to start using it on all of your software projects. It can even be used retroactively on legacy projects to address issues like bugs or refactoring.
The concept is very straightforward, use a host running an automated testing framework to act as a user with the intent of testing a piece of software. This can be anything from a bespoke script to a full blown automation and deployment server capable of running multiple simultaneous test clients. In either case using this testing methodology will end up saving time and money for a number of reasons.
The best part about automated testing is the write once, run multiple times aspect of it. With manual testing a tester must follow a script to perform a test every single time. With automated testing, a developer writes a test once and can run it whenever necessary with the click of a button.
What’s more is that you can be sure the test will be run the exact same way every time. No more wondering if timing issues are throwing off a test, or losing track of which step you are working on. Automated testing performs the exact same steps in the same order with the same timing every time. And if you suspect timing of events is something that could be causing different responses from the system, that’s just another parameter you can add to your test!
Automation makes it easier to provide better test coverage of more functionality and data inputs for your software project. This gives a tremendous advantage over manual testing by ensuring that more of your software project is actually tested. It builds confidence in the suitability of the software to perform as expected under all conditions.
Implementing a single test case for a function can be leveraged into testing all possible inputs for that function by running the test multiple times with different data inputs. Plus various functional tests can be grouped together to perform system level tests using a library of test cases. This gives more complete and more rapid functional test coverage that can be achieved by manual testing alone.
Long Term Testing
A major drawback of manual testing is that any tests longer than a few minutes, or even hours, are not possible to do. The reality is that no one wants to sit and watch a test run for that long, automated testing can help with this.
Once an automated test has been written, that test can be run continuously without any further user intervention. Furthermore test cases can be extended longer than a manual test. Tests can be run back to back in an endless loop and randomized to ensure there are no dependencies between cases.
Another aspect of long term testing is the ability to run stress tests. For example a web app may function correctly with a single user, but fails when multiple users are using it. Automated testing can easily uncover these kinds of deficiencies, just by running several tests in parallel.
It can also test how well the software being tested scales up. Instead of waiting for the popularity of the app to increase to the point where it breaks, testing can uncover exactly how much capacity is available before it does so. A very useful metric to minimize downtime for mission critical software.
Agile methods espouse the virtues of short development cycles, which include testing at the end for all new features. But how can we be sure that our new work didn’t break some of the old features? Enter automated testing.
Every time a new feature is added an automated test should be written for it, and it should go without saying that the feature isn’t “done” until the test passes. That same test can and should be run any time another feature is added. This way your testing can uncover any interactions between the old and new features that might cause a problem.
Ideally with testing no bugs should ever make it into production code, however it does happen. Whenever a bug is found in the wild an automated test can be written for it which fails, then when the bug is fixed it should be tested again to verify that the fix works as expected.
Writing an automated test case and perfecting it will probably take longer than performing a manual test. Despite having to set up a test framework and writing test cases, automated testing can actually save time during development though.
The main time saver is during development, tests will probably need to be run multiple times to get the software working correctly. Running a single manual test is faster than writing an automated test and running it. But running an automated test multiple times is trivially longer than running the same test once.
Automated tests can produce reports which prove that tests have been run and pass on a software project. This may not be of much interest to developers but the ability to show managers or customers a report that shows the software they have invested in is complete and works as expected.