The 3-tier architecture is a typical software testing approach followed by most development and software testing teams. Among the three layers or tiers of logical computing that this architecture consists of, the first one is the client tier, more popularly known as the presentation layer. The second tier is the business layer or application tier, and the third tier is the database or data layer. Each of these tiers undergoes thorough software testing to validate the quality of an application or product. The testing procedure that is conducted at the first or client tier is known as Front-end testing. Whereas, the testing procedure conducted at the second and the third layers are called back-end testing.
Each of these two testing types has some distinct features of their own. Let’s discover how.
Front-end vs. Back-end Testing
As the name suggests, front-end testing is done for the first, presentation stage of the 3-tier architecture system, while back-end testing is carried out to check the second and the third tiers.
Kind of testing
Front-end testing: The Graphical User Interface (GUI) is mandatory for testing to be performed.
Back-end testing: It may or may not use the GUI for the test and involves the testing of business logic and databases. It is instead performed on AUI (Application User Interface) and the database stages.
Necessary software testing skills
Front-end testing: Apart from sound knowledge about the requirements of the business, to conduct this test, the software tester must have experience in managing and working with tools and frameworks related to automation.
Back-end testing: For performing proper back-end testing, the software tester requires strong database skills along with proper knowledge of the concepts of SQL or Structured Query Language.
Front-end testing: For front-end testing, no information needs to be stored in the database.
Back-end testing: It is necessary for back-end testing, that information is stored into the database.
Purpose of the tests
Front-end testing: The importance of front-end testing lies in the fact that the application’s complete functionality is checked through this testing process.
Back-end testing: This software testing type is mainly necessary as it checked for the corruption of data, deadlocks, and loss of data.
The types of testing
Front-end testing: The varieties of tests that are conducted during the front-end testing include acceptance testing, unit testing, regression testing, and accessibility testing.
Back-end testing: The most commonly used testing types during back-end testing include API testing and SQL testing.
Commonly used tools
Front-end testing tools:
The most popular front-end testing tools include –
- LiveReload – A web protocol that is simple enough; one of the primary functions of LiveReload is triggering events to clients every time there is a modification in files.
Back-end testing tools:
The most preferred tools used for back-end testing are –
- Data Generator – The DTM Data generator tool is a popular back-end testing tool. In database testing, it is used to schema objects apart from generating data rows. With the help of this tool, you can conduct load testing, performance testing, as well as usability testing to check the database.
- Data Factory – A tool for database testing, Data Factory works as a data manager, as well as a data generator. The interface of this tool is quite easy to use, and this tool is also accomplished in the handling of complicated data relationships.
- Mockupdata – This is a software tool, which is utilized to generate test data along with foreign keys. With the help of this tool, you can use SQL commands like Updates, Select, and Delete. Numerous relational databases and sequential files are also supported by this tool.
The benefits of each type
Pros of Front-end Testing:
- In the case of website testing, while detecting the proper bottlenecks in the server is essential, it is equally essential to identify the issues in the client-facing performance. Since this has a significant impact on the user experience, front-end testing benefits in providing a positive impression
- By an increase of 50% in the front-end performance, the cumulative performance of the application gets enhanced by 40%.
- This is easier and more cost-effective than other testing processes.
Back-end testing benefits:
- Unlike black-box testing, back-end testing is based on the level of data integration and its significance to the organization.
- Since this is an in-depth testing procedure, this testing provides maximum test coverage
- In this process, defects can be easily detected in the early phase of testing, that is at the development stage
Although the above pointers reveal that there are many differences between front-end and back-end testing, to make an application or product completely risk-free, both front-end and back-end testing processes need to be combined to achieve the holistic result.