According to research conducted by AIMultiple, a developer of AI solutions, in 2022, 45% of surveyed companies used automation to facilitate unit testing. While automation of unit testing is becoming increasingly popular, it is important to note that unit testing and automated testing are not the same, as they represent two distinct testing concepts. To understand why these terms should not be used interchangeably, let’s delve into a detailed comparison of unit testing vs automated testing.
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What is automated testing?
Automated testing is a broad term that does not specify any particular testing methodology. Instead, it defines a testing approach based on the use of tools and frameworks to complete testing tasks without human assistance. The primary goal of automation in testing is to reduce manual effort, while the specific objectives of automated testing can vary depending on the chosen methodology.
What components of testing can be automated?
The core functionality of tools used for test automation primarily involves automating test execution. However, many test automation solutions offer additional features that allow the automation of various associated tasks. Here are some of them:
- Test scheduling;
- Test scenario generation;
- Assistance in test cases and test data generation;
- Script creation;
- Data-driven testing;
- Integration with Continuous Integration (CI) and Continuous Deployment (CD);
- Defect reporting;
- Security scanning;
- Test reporting, test result analysis, as well as test metrics and dashboard generation;
- Test coverage analysis;
- Test script maintenance;
- Test execution on multiple platforms;
- Compliance reporting.
What types of tests can be automated?
Repetitive and rule-based testing processes are commonly automated in various testing types. While unit testing is one of them, the list includes many other testing methodologies, such as:
- Integration testing;
- Regression testing;
- Functional testing;
- Performance testing;
- Compatibility testing;
- Security testing;
- And others.
At the same time, most testing types that require subjective evaluation, creativity, and human judgment, including exploratory testing, usability testing, and user experience testing, have not been successfully automated yet.
What is unit testing?
Unlike automated testing, which is a general approach that involves using tools to streamline testing processes instead of relying on manual work, unit testing is a specific methodology. Its primary goal is to break down code into isolated units and assess their performance. It does not specify whether testing must be performed manually or with a test automation tool. However, as mentioned earlier, unit testing is one of the tests that can be effectively automated.
Let’s explore the core features of unit testing below to gain a better understanding of this methodology and compare unit testing vs automated testing.
1. Isolation
As mentioned earlier, code is broken down into units, which should be separated from any external dependencies that are not subjects of testing. Unit testing also requires test data independence to ensure that tests do not rely on external data sources. Additionally, a common practice is to utilize test doubles as controlled test data.
2. Granularity
Unit testing is known for its narrow focus, with units under testing typically being small sections of code, often reduced to a single function or method.
3. Independence
Unit testing aims to achieve independence in the results of testing separate units. This means the outcome of testing one unit cannot affect the test results of another one, and the order of test execution is also of no importance.
4. Repeatability
If the code does not change, unit tests are expected to produce the same results if repeated.
5. Fast execution
Unit tests are designed to be executed quickly and are frequently used during the development stage, allowing developers to catch and fix bugs early.
6. High code coverage
Unit tests are intended to execute virtually every line of code within a unit, contributing to high code coverage.
7. Documentation
The design of unit test scripts allows companies to use them as a form of documentation that can provide insights into code behavior.
8. Regression support
Unit testing can be a useful component of regression testing practices, as it helps testers detect negative impacts on units caused by code changes.
9. Maintenance support
Unit tests can also assist in code maintenance by helping with detecting code changes and refactoring.
10. Test-Driven Development (TDD)
TDD, the methodology of writing tests before the code to guide the software development process, relies on unit tests.
11. Automation
As mentioned earlier, unit testing can be successfully automated. However, manual test execution is also possible.
Automating unit testing
The market offers a range of solutions for automated unit testing, from open-source frameworks adaptable for unit testing in virtually any application to proprietary tools designed specifically for testing particular applications. Additionally, some development teams provide dedicated solutions for testing their own software.
Some of these tools, particularly those distributed as libraries and frameworks like Selenium, may require significant manual work to set up a testing environment, create and maintain test scripts, and generate reports. In contrast, more user-friendly no-code solutions, such as Executive Automats for Microsoft Dynamics 365, support testers with a graphical interface, reducing the time required for test script preparation significantly.
Unit testing vs automated testing – the bottom line
Unit testing and automated testing are two distinct testing concepts. Unit testing is a specific methodology that involves breaking down code into independent units for testing, while automated testing encompasses any type of testing supported by an automation tool.
However, these two concepts can overlap because the nature of unit testing makes it a perfect candidate for automation. At the same time, many other types of testing, including performance testing and functional testing, can also be effectively automated.