“Test what you write before it goes live” has become legendary and essential for preserving a company’s reputation and retaining users over time. After all, neglecting or overlooking software testing may have a significant negative impact on your company.
To provide a perfect user experience, successful businesses have traditionally spent a significant amount of money in software testing. SoundCloud, for example, has enhanced its testing infrastructure and built a well-balanced test pyramid to address issues such as test flakiness and pipeline wait times. It allowed them to save time, money, and their reputation.
To prevent potential software issues, world-class development teams follow a well-established testing cycle, which is a no-brainer. When it comes to quality assurance, however, there is no one-size-fits-all solution. As a result, it’s essential to choose the appropriate software testing method and approach for your product and development team.
Several kinds of testing are often done throughout the software development cycle, although functional testing and integration testing are the most common. However, owing to erroneous definitions for each on many developer forums, both of these are often mistaken with other testing techniques such as system testing, performance testing, and security testing.
The key distinction between functional and integrated testing is when, why, and how they were conducted. Our goal with this blog is to clarify the differences between functional and integration testing using various use case examples.
What's the Difference Between the Two?
Despite their similarities, there are some significant distinctions between functional and integration testing. Functional testing verifies that the program meets functional requirements, while integration testing verifies that components work together. Here’s a comparison chart to help you grasp the major differences between the two.
What is Functional Testing and How Does It Work?
Functional testing ensures that the application’s functions, features, and modules are performing as expected. It is an useful testing technique for businesses to improve software quality by removing faults or mistakes.
Experts’ Opinion: Functional testing has the advantage of evaluating a complete range of potential faults that unit testing does not cover.
Consider an eCommerce application in which a user makes a purchase. Developers send the build to the QA team for testing once they finish creating the feature. The QA team examines the build and creates test cases to verify the following:
- Is the database’s transaction history properly stored?
- Is the transaction information shown on the user’s screen in a timely manner?
- Is there anything obstructing or terminating the transaction in the middle?
What is Integration Testing and How Does It Work?
Integration testing focuses on evaluating several modules as a single unit, as well as their interactions. It is carried out after the integration of several components or modules in order to identify faults related to the interfacing of such components or modules.
Consider a web application that consists of two modules: a login page and a home page. After the modules have been integrated, testers must look for flaws in the interface between them. Integration testing will look for the following:
- What is the connection between the login page and the home page?
- Is the welcome message shown when the user logs in to the web app?
- After signing in, will the user be sent to the welcome page or the home page?
Integration testing examines the database’s performance, data flow, and any changes that occur.
Functional Testing vs Integration Testing: What's the Difference?
Why are various kinds of testing so important in the software testing lifecycle? Let’s look at the differences in their objectives that distinguish both kinds of testing.
What is the purpose of functional testing?
This testing will look at the user interface, end-to-end processes, database, APIs, security, and client/server connectivity, among other things. Each feature is tested by giving particular inputs to ensure that the program behaves as anticipated. To guarantee software quality, the test result is compared to the anticipated output.
Integration Testing's Purpose
The main goal of integration testing is to ensure that a system’s functionality and performance are not compromised when several modules are combined. It checks the performance of various modules once they’ve been integrated. It is carried out by a dedicated test group that focuses on the application interface and data flow between modules rather than overall functioning. This testing is usually started after unit testing.
Pros & Cons – Functional Testing vs Integration Testing
The Benefits of Functional Testing:
- User satisfaction: Ensures that end-users get at least acceptable program performance.
- No defect assurance: This kind of testing streamlines all software functions by identifying and eliminating defects that arise during the test.
- Ensures security: Functionality testing looks after the software’s security and ensures that major flaws are discovered and prevented.
- Simulate real user behavior: Functional tests are performed based on actual user behavior rather to making assumptions about the system’s structure.
- Risk-free tests: By assessing the key functions and features first, it minimizes the risk and loss associated with the program.
- Customization of Test Cases: This testing allows you to build several kinds of functionality-based test cases to meet your specific needs.
Functional Testing's Drawbacks:
- Logical errors: It’s easy to overlook the possibility of logical interlinking between programs, libraries, and so on.
- Expensive: This testing necessitates the repetition of certain test cases, resulting in duplication and potentially increasing the testing cost.
- Complexity: If the features are closely linked, a minor change in one function may impact the whole program, making the testing circumstances complicated.
- Time-consuming: Functional performance may be assessed by creating time-consuming context-specific tests.
- No assurance of deployment: There is no guarantee that the product is fully bug-free and ready to go live.
The Benefits of Integration Testing
- Testing flexibility: Instead of waiting for all of the modules to be put together for testing, testers may start integration testing anytime any relevant module is ready.
- Less Risky: Reduces the likelihood of software failure by reducing the total number of defects and the negative impact of code modifications.
- Easily detects errors: Detects flaws with interfaces, data formatting, and third-party services that were overlooked during unit testing.
- It encourages engagement by validating the integrated modules’ and third-party APIs’ functional and non-functional behavior.
- Maximum Test Coverage: Integration testing has a broad scope since it may test many modules, improving the findings’ dependability.
Integration Testing's Drawbacks
- Faults in Program: Testing takes longer, and test cases that aren’t addressed may lead to faults and malfunctions in the software being missed.
- Failure of the testing process: Any error or omission in the testing strategy may turn the whole testing process into a catastrophe.
- Time-consuming: Integration testing flaws are tough to correct and require a long time.
- Dependency on Stubs and Drivers: To conduct this testing, you must create stubs and drivers properly. If not, it may lead to insufficient testing.
Functional Testing vs. Integration Testing Challenges
From collecting requirements through developing and running test cases that evaluate the whole program for flaws, the software testing process is broken down into many stages. There are many unexpected difficulties that may emerge throughout the procedure. Let’s have a look at the dangers you may encounter when conducting functional and integration tests to prevent irreversible consequences:
Functional Testing Challenges
- Because test requirements include comprehensive and quantifiable information, it’s difficult to properly specify test requirements for each change.
- Because this test divides reporting in terms of features-based and defects-based, maintaining a simple report to identify go/no go choices with functional tests may not be completely feasible.
- During the test, it was difficult to overcome the mismatch between the needed functionality and the test strategy.
- Resolving recurrent problems and building up the test environment took a long time.
- It’s possible that re-planning the first test approach for various functions may result in confusion.
- Due to software complexity and variety in test needs, creating test metrics to examine and enhance a program is not completely feasible.
Integration Testing Challenges
- When mocked data is replaced with actual modules, additional problems may emerge.
- Because programs and data required for testing are mocked, writing integration tests takes time and needs strong programming expertise.
- Because the software code is developed by different teams independently, it is difficult to comprehend the rationale.
- Testing integrated modules is difficult due to the impact of many variables such as the database, platform, and software environment on the testing process.
- Following a variety of testing methods and combinations makes it more difficult to choose the best one for testing.
- When externally integrated features, tools, and libraries affect the application and are developed by various businesses with distinct dependencies, integration testing becomes more complicated.