Software testing: methods, types of testing and quality gates
"What's this talk about 'release'? Klingons don't 'release' their software.
We let the software out of its cage to leave a trail of designers and quality controllers in its bloody wake.”
[From: The 11 most common statements made by Klingon software developers]]
Why software testing?
Fortunately, we have no Klingons on the inSyca team! We prefer to check and test our software solutions before we unleash them on mankind – better safe than sorry.
But seriously: in our digital (business) world, software has become an essential part of daily life. Be it enterprise applications or mobile apps and integrated systems – the quality of software plays an important role in the success of companies and the satisfaction of end users.
As a service provider for solutions in areas such as EDI and the integration of systems, applications and data, software testing has always been a high priority for us.
But how do we ensure that the software we develop meets the highest quality standards?
Clearly, software must be carefully and thoroughly tested: during software testing, applications are put through their paces to ensure that they function properly and meet all requirements.
In this blog post, we will take a closer look at the topic of software testing. In particular, we will focus on Test-Driven Development (TDD), various methods, types of testing, and the importance of quality gates.
First things first: the importance of Test Driven Development (TDD)
Unter Test Driven Development (TDD) is a software development paradigm in which tests are written before the actual code The process involves three steps:
- First, a test is created that describes the desired behavior of the function to be developed.
- Then the minimum code necessary to pass the test is written.
- Finally, the code is optimized to make it more readable, efficient and maintainable without changing the functionality.
There are good reasons for Test Driven Development: for one thing, this method requires careful planning and a clear understanding of the requirements before implementation begins. By writing the tests first, we ensure that the code works as intended and that potential errors are detected early.
In addition, TDD improves code quality because the focus is on writing clear, modular and well-structured code. As a result, Test-Driven Development leads to higher productivity and reduces the costs and effort required to correct errors at a later stage.
By the way, it was the American developer and author Kent Beckwho established the test-first approach in software development in the late 1990s.
What software testing methods are there?
Software testing methods include the strategies, processes or environments used to test the quality of software. The two most widespread methods are arguably the Agile and the waterfall model – both approaches differ greatly in their approach.
The waterfall method
The waterfall model is a traditional Software Development Life Cycle (SDLC)model that consists of a linear sequence of phases, with each phase building on the previous one. In the context of software testing, this means that testing is carried out in separate phases after development.
The waterfall model is usually divided into five phases:
- Requirements analysis: defining and documenting the software requirements.
- System design: creating the design for the software architecture and structure.
- Implementation: writing the actual code based on the specifications from the previous phases.
- Testing: testing is done after development; different types of tests are used.
- Maintenance: once all tests have been passed and the software has been released, maintenance including bug fixing and updates is carried out.
Since the waterfall model only allows for software testing at the end of the development process, errors may only be detected and corrected late in the process. This can lead to higher costs and longer development times, especially if errors are only detected in advanced phases.
We therefore recommend this method only for small projects with low complexity and few processes and participants.
Die Agile Methode
As the name suggests, the Agile software testing method is linked to the principles of agile software development. In contrast to the waterfall model, testing in agile development is not carried out in separate phases after development, but is continuously integrated throughout the entire development process.
The main features:
- Continuous testing: testing is done in short iterations or sprints of about one to four weeks.
- Test Driven Development (TDD): tests are written before implementation and define the expected behavior of the software, or serve as specifications for development.
- Automation of tests: promotes a fast development cycle, tests can be carried out efficiently and frequently.
- Continuous Integration and Deployment (CI/CD): Using CI/CD pipelines to integrate, test, and deploy code regularly -> continuous delivery of software and rapid response to changes or issues.
- Collaboration and communication: testers work closely with developers, product managers, and other team members to understand requirements, design tests, and share feedback.
By taking this approach, the Agile testing method ensures faster software delivery, higher quality and flexibility, and better adaptability to changing requirements and customer needs.
The DevOps method
The DevOps model is closely related to the agile approach: the term DevOps is composed of development and operations and describes a method that incorporates both development and operational aspects.
The approach to software testing is basically the same as the Agile method, with continuous testing at sprint intervals, TDD, automation, etc.
However, while Agile focuses on software development itself, DevOps focuses primarily on improving delivery speed and quality by eliminating the separation between development and operations.
Despite, or perhaps because of, the different focuses, the two methods complement each other very well.
What types of software testing are there?
In software testing, there are different types of tests, also known as test procedures, which are used in various areas of software engineering to check the functionality of software. Here, different types of test procedures can be distinguished, including:
Functional testing
The aim of functional software tests or function tests is to check the functional correctness of a software application. Essentially, functional tests are carried out to ensure that the software does what it is supposed to do, and does it in a way that meets the specifications.
This typically involves testing user inputs, executing actions within the application, and checking the results.
The four most common functional tests include:
- Unit testing: : unit testing is the process of testing the individual software modules/components that make up an application. These tests are usually carried out at the smallest level of software development, such as individual methods or functions. The purpose of this type of testing is to ensure that each unit of the software works properly and can be tested independently of other parts of the system.
- Integration tests: in contrast to unit tests, integration tests are used to test the interaction of the various components of an application. Integration tests are usually also referred to as End-to-End Tests (E2E Tests) and can be carried out at different levels, from the integration of classes or modules to the integration of services or systems.
- System testing: finally, system testing involves comprehensive testing of a system in its entirety. Ideally, the software and hardware components involved will have already successfully passed unit and integration tests. This type of software testing is based on the black box test method, in which the software is tested under real user conditions and under special exception scenarios.
- Acceptance testing: This focuses on the end user of a software and the user-friendliness of an application. These tests simulate typical user scenarios and check whether the software meets user expectations and is intuitive to use, for example. Acceptance testing is usually carried out after development is complete to ensure that the application is ready to be accepted and used by the customer.
Non-functional testing
Not only the functionalities of a software should be thoroughly tested, but also non-functional parameters such as performance, security, usability and scalability should be given attention.
With non-functional tests, we determine whether the software meets user expectations and industry standards. Without this type of testing, potential problems such as slow performance, security vulnerabilities or an inadequate user experience could go unnoticed and thus affect the acceptance of the software.
Examples of non-functional tests:
- Performance testing: the performance of the software is tested, including response times, scalability and resilience under various load conditions.
- Security testing: the security of the software is the focus here, to protect it from threats such as hacking, data leaks or unauthorized access.
- Usability testing: The user-friendliness of the software is evaluated, including the user interface, navigation and general user experience – similar to acceptance testing.
- Compatibility testing: here, you test if the software works properly on different platforms, operating systems, browsers or device types.
- Reliability testing: The reliability of the software is tested, including its ability to function stably and avoid unexpected failures.
- Accessibility testing: It is also important to ensure that the software is accessible and that users with disabilities can access it.
Regression testing
Regression testing is used to determine how new changes or updates to a software application affect existing functionality. It is important to perform regression testing to ensure that parts of the software that have already been tested and found to work continue to function properly after a change.
Regression testing can be both functional and non-functional, depending on which aspects of the software are being checked:
- Functional regression testing: this refers to the software's existing functionalities and that it continues to work correctly after a change. This also includes re-running test cases that have already been executed to ensure that no new errors have been introduced.
- Non-functional regression testing: this type of testing checks the aspects of software quality that are not necessarily counted among the functional requirements of the software (performance, security, usability and scalability). In this case, changes to the software are tested to ensure that they meet the existing non-functional requirements and have no negative impact on these aspects.
What types of software errors are there?
After we have dealt in detail with the different types of software testing, it is also worth taking a look at the various sources of error. In connection with software errors, the term Bug is often used – bug, like beetle :)
Bugs appeared in the early days of the first computers. At that time, computers still existed as huge calculating machines in which insects could easily get lost and cause errors in the system.
A vivid example is provided by a logbook entry from 1947 – complete with a glued-in bug – when a bug was found in the Mark II Aiken Relay Calculator .
But legend has it, that Thomas Edison is said to have spoken of bugs as early as 1878, when he complained about difficulties with his inventions.
But let's take a closer look at the most common software bugs:
- Logical errors: logic errors occur when the code does not produce the expected results or behave as expected. They are also tricky: they often arise from errors in the algorithm or in the logic of the program and can be difficult to find as they do not necessarily cause the application to crash.
- Syntax errors: syntax errors occur when code violates the rules and structures of the programming language. These errors are often detected during compilation and prevent the code from being executed.
- Runtime errors: by contrast, runtime errors occur during program execution and are not detected during compilation. They can be caused by unexpected input, missing resources or unexpected conditions in the program flow and often lead to program crashes or unexpected application behavior.
- Interface errors: these errors occur when communication between different modules or components of the software is not working correctly. They cause data to be transferred or interpreted incorrectly, resulting in application malfunction.
- Performance issues: these occur when software does not perform as expected, for example, long loading times, high memory usage or poor response times. These problems may be due to inefficient code, inadequate resource allocation or scalability issues.
Software testing and quality gates
What are quality gates?
Quality gates are defined milestones or criteria in the software development process that determine when certain phases are completed or when a production release can be approved.
They serve as important checkpoints to ensure that certain quality standards are met before a project or phase is continued.
The role of quality gates in software testing
- Quality control: quality gates ensure that the software meets the defined quality standards and requirements.
- Risk management: Quality gates allow potential risks to be identified and addressed at an early stage, before they develop into larger problems.
- Decision-making: they provide clear criteria for making informed decisions about whether to continue a project or release a product.
- Increased efficiency: implementing quality gates can help to avoid unnecessary costs and delays by identifying and resolving issues early on.
- Stakeholder communication: quality gates are also a useful tool for communicating with stakeholders about the progress of the project and the quality of the software.
As we see, the use of quality gates goes a long way towards improving the quality and reliability of software products so that they meet the requirements of users and the organization.
Conclusion
Software testing will be important in the future because software technologies and requirements are constantly evolving – and the challenges and demands are not diminishing.
With the advent of artificial intelligence, machine learning, the Internet of Things (IoT) and other innovations, software testing challenges are also becoming more complex. It is important that software testing practices and tools keep pace with these developments and evolve to meet growing demands.
Automation, continuous integration and continuous delivery (CI/CD), DevOps practices and Agile testing will keep on playing a major role in increasing the efficiency and speed of software development processes.
In addition, non-functional testing, such as performance, security and usability testing, will become more important to ensure that software not only works smoothly but also meets performance, security and user experience requirements.
It is therefore worth investing in comprehensive software testing: for more quality and reliability in software products and ultimately more success in development projects, both today and in the future.
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