Why Unit Testing to be Automated?

Unit Testing

An automated unit test suite gives you a number of unique advantages in comparison to other testing strategies; let us take a quick look at some of the possible reasons why unit testing is to be automated:

  1. Automated unit testing fixes issues effectively as early as it can, long before the customer gets to use the software, and even before the QA team eliminates them. Most issues in new code are uncovered before now the developers/coders check code into source control.
  2. An automated unit test suite keeps watch over the code in two dimensions: space and time. In time dimension, it ensures that code written works now as well as in the future: With respect to the space dimension, the unit test that you write for some other feature guarantees the new code doesn’t infringe upon them; similarly it ensures that the coding done for other features doesn’t adversely impact the code written for this feature.
  3. Refactoring a code is altering some code without affecting its behaviour, whilst at the same time integrating new features to the software. Automated unit testing should be set up before refactoring or cleaning up the current code to achieve a clean code structure.
  4. When you run the unit tests applying the fixes, they will uncover unwanted sideeffects. Releasing quick fixes is neither the solution, nor is publishing hotfixes – only an automated unit test can reduce such things, whilst without causing new problems.
  5. Automated unit testing can improve the project’s truck factor, nothing but the number of coders that if, supposing, hit by a truck would bring the project to a standstill. By improving the truck factor of the project, the developer would find it easier to take over and work on a piece of code he/she is not thoroughly familiar with. Remember if your project’s truck factor is ‘1’, then it is under higher risk.
  6. Last but not least, automated unit test brings down the need for a project’s manual testing. Though some manual testing will be required, running an automated unit testing is not only costeffective but critical to perform the mundane testing, while the QA team can deal with the hardtofind bugs.

The combined effects of the benefits discussed above will transform the area of software engineering to be more repeatable and predictable, similar to an engineering discipline, while not putting the ‘art’ in design and coding phases completely out of context. What automated unit testing can do, at best, is to remove the shortcomings of the adhoc approach in software development which is the major reason for several problems that confront software projects.

Importance of Writing Unit Tests

Unit testing, a key area of agile software development process, is excellent for designing robust software, thereby maintaining code and eliminating the glitches in code units. The QA team should never accept any build for verification in the case of any of the failure of the unit tests. This, when made into a standard process, can help catch defects in the early project development cycle, saving valuable time.


  • Testing can be conducted right at the beginning phase of the software development lifecycle.
  • Bug fixing in unit testing can solve several other issues occurring in the testing and later development cycle.
  • Cost involved in fixing a defect and the number of bugs is lower than of acceptance or system testing.
  • Code coverage can be effectively measured.
  • Code completeness can be achieved running unit tests.
  • Robust design and developers, as coders, write test cases only by taking in the specifications first.
  • Easy to identify who disrupted the build.
  • Shortened development time due to reduced defect count

How will you write good unit tests?

A unit test should be written for the verification of a single unit of code and not the integration. Smaller chunks and isolated unit tests with well defined naming would render it easily maintainable and simple to write. If one part of the software is changed, it shouldn’t affect the unit test if those are small and isolated and developed for a particular unit of code. It should run fast and the unit test must be reusable.

Myths and Truths:

1. Myth: Writing code with unit test cases is time consuming

     Truth: Saves up development time , as a matter of fact.

2. Myth: Unit testing will find every single bug 

     Truth: It is aimed at building robust software component having less number of defects in the later phases of SDLC.

3. Myth: 100 percent code coverage means 100 percent test coverage

     Truth: No guarantee for errorfree code

How unit testing improves manageability?

Unit testing can help managers control and manage projects better. Functional managers and project managers are focussed on the core activities of the developers. Unit testing can enhance management in a gamut of areas such as reporting and visibility, control and course correction, speed and efficiency, predictability and planning, and customer satisfaction.

How automated testing can help?

Automated testing is an excellent way to check if the code is functional and continues to do so as intended. Here are specific objectives that must be met:

The developer should be able to run the collective efforts of all the developer’s tests. The CI (continuous integration) server must run the complete range of tests sans any manual intervention. The test outcome must be iterative and unambiguous.

The primary objective is a range of automated unit tests that help any coder to verify that their current set of changes don’t disrupt existing code under test, thereby eliminating undesirable or accidental outcomes.

The second objective is vital in that the CI server can run these tests integrated as part of the thorough and full build cycle, thereby allowing it to verify the efficiency of the system. If you’re a developer you can run the complete automated test suite with zero configurations or setups.

The third objective demands the tests be correct, consistent and clear. This means whether a change in the code necessities the tests were through before or if the tests will prove successful if tests are rerun.

The Bottom Line

Unit testing requires proper execution and consistency. Software projects are quite effective at offering the correct solution in a managed and predictable way. Three objectives to bear in mind when you begin to write your unit tests:

Readability – Writing test code that communicates for itself and simple to understand

Maintainability–Writing test code that are consistent over time and robust

Automation– Writing test code that need zero to little configuration and setup  

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