7 Common Types of Software Bugs Every Tester Should Know
By Jash Unadkat, Community Contributor - March 21, 2023
Software bugs are an inevitable part of the software development life cycle. No code is perfectly crafted at its first go. Bugs, anomalies, and errors need to be identified, recorded, and resolved. Therefore, creating a robust software product requires comprehensive testing and optimizations.
Throughout the testing process, teams are bound to encounter specific bugs that obstruct the development and testing process. If these bugs are not resolved in the early stages, they will disrupt the workflow in the later stages, and fixing them becomes far more challenging and time-consuming.
However, if testers are aware of the most common types of bugs or defects they are likely to encounter, they can tackle them earlier, faster, and more effectively.
Different Types of Software Bugs
This article discusses the most common types of software bugs or defects encountered in software testing so that developers and testers can deal with them better.
1. Functional Bugs
Functional bugs are associated with the functionality of a specific software component. For example, a Login button doesn’t allow users to login, an Add to cart button that doesn’t update the cart, a search box not responding to a user’s query, etc.
In simple terms, any component in an app or website that doesn’t function as intended is a functional bug.
Such bugs are often detected when testers conduct comprehensive functional testing for their apps or websites in real user conditions. Teams need to ensure that all the functional bugs are resolved in the early stages so as to avoid delivering bad user experiences in the production environment.
2. Logical Bugs
A logical bug disrupts the intended workflow of software and causes it to behave incorrectly. These bugs can result in unexpected software behavior and even sudden crashes. Logical bugs primarily take place due to poorly written code or misinterpretation of business logic. Example of logical bugs include:
- Assigning a value to the wrong variable
- Dividing two numbers instead of adding them together resulting in unexpected output
3. Workflow Bugs
Workflow bugs are associated with the user journey (navigation) of a software application. Let’s consider an example of a website where a user needs to fill up a form regarding their medical history. After filling the form, the user has three options to choose from:
- Save and Exit
- Previous Page
From the available options, if the user clicks on “Save and Exit,” the user intends to save the entered information and then exit. However, if clicking on the Save and Exit button leads to an exit from the form without saving the information, it leads to a workflow bug.
4. Unit Level Bugs
Unit level bugs are very common, and they are typically easier to fix. Once the initial modules of software components are developed, developers perform unit testing to ensure that the small batches of code are functioning as expected. Here’s where developers encounter various bugs that get overlooked in the coding stages.
Unit level bugs are easier to isolate as developers deal with a comparatively small amount of code. Moreover, replicating these bugs takes less time, so developers can track the exact bug and fix it in no time.
For example, if a developer creates a single page form, a unit test will verify whether all the input fields are accepting appropriate inputs and validate buttons for functionality. In case a field doesn’t accept the appropriate characters or numbers, developers encounter a unit-level bug.
Also Read: Popular Unit Testing Frameworks in Selenium
5. System-Level Integration Bugs
System-level integration bugs primarily pop up when two or more units of code written by different developers fail to interact with each other. These bugs primarily occur due to inconsistencies or incompatibility between two or more components. Such bugs are difficult to track and fix as developers need to examine a larger chunk of code. They are also time-consuming to replicate.
Memory overflow issues and inappropriate interfacing between the application UI and the database are common examples of system-level integration bugs.
6. Out of Bound Bugs
Out of Bound Bugs show up when the system user interacts with the UI in an unintended manner. These bugs occur when an end-user enters a value or a parameter outside the limits of unintended use — for example, entering a significantly larger or a smaller number or entering an input value of an undefined data type. These bugs often pop up in form validations during functional testing of web or mobile apps.
Must Read: A Detailed Guide on Bug Tracking
7. Security Bugs
Security is a major concern for software development. Security Bugs are a major risk for users and should be taken very seriously and resolved. Due to their high severity and vulnerable nature, security bugs are considered among the most sensitive bugs of all types and should handled with criticality and urgency. These bugs might not hinder the operation but can compromise the whole system. These should be checked thoroughly at regular intervals.
The Role of Real Devices in Bug Identification
For any software product (mobile app or web app) to be successful in a highly fragmented environment, it needs to be thoroughly tested in real user conditions. This helps in detecting and resolving the maximum bugs an end-user might encounter in the real world.
Extensive testing requires a comprehensive device lab that enables testers to test their web and mobile apps across diverse device-browser-OS combinations. Bear in mind that setting up a comprehensive testing digital lab requires significant financial investment and maintenance effort. Naturally, this is not feasible for all organizations.
Interesting Read: Understanding Browser, OS and Device Fragmentation
Cloud-based testing platforms like BrowserStack help teams of all sizes by providing them the necessary test infrastructure for comprehensive testing. One can test on a wide range of devices (mobile and desktop) running on unique operating systems like Android, iOS, Windows, or macOS.
Needless to say, the entire QA process hinges on the use of a real device cloud. This is true for manual testing and automation testing. QA’s can also choose to conduct Cypress testing on 30+ real browser versions.
Use BrowserStack’s cloud Selenium grid of 2000+ real browsers and devices to run all requisite tests in real user conditions. Manual testing is also easily accomplished on the BrowserStack cloud. Sign Up for free, choose the requisite device-browser combinations, and start testing.
Additionally, BrowserStack also offers a debugging toolkit that makes it easy to verify, debug and fix errors.
Listed below are the range of debugging tools offered by BrowserStack’s Mobile and Web testing products:
- Live: Pre-installed developer tools for desktop browsers and Chrome developer tools on real mobile devices.
- Automate: Video Recording, Screenshots, Text Logs, Network Logs, Selenium Logs, and a few others.
- App Live: Real-time Device Logs from Logcat or Console
- App Automate: Video Recording, Text Logs, Screenshots, Network Logs, Appium Logs, App Profiling, and others.
With such an inclusive test infrastructure, teams don’t need to worry about taking any additional efforts to set up a complex device lab. Simply sign-up for free -> select the desired test environment, -> start testing remotely from anywhere in the world.
As mentioned earlier, developing flawless software needs comprehensive testing, debugging, and optimizations. Regardless of the bug type, testers must ensure that the majority of bugs are identified and resolved in the early stages to avoid rework in later phases. Naturally, having clarity on the most common types of bugs will help developers avoid mistakes in the development process.