How do you define test levels and types in agile methodology?

In my experience , a Test Driven Software development of any product is the key to its Quality and outcome of product. Early Testing and strategies need to be introduced while the product is under design and development. In addition to the regular requirements translations at a functional level, one has to also develop Test requirements and ensure a traceability chart to each Functional requirement. Then the regular Test strategy travel from Unit-acceptance-functional-early system-system testing to production needs to be iterated. This also involves the negative and performance to measure at scale. E2E testing plays a vital role that has a similar actual topology where the product or component is integrated and interop testing is vital

In my perspective, test levels are an essential aspect of the software testing process. Each test level has its specific objectives, techniques, and deliverables. Unit testing, integration testing, system testing, and acceptance testing are the 4 test levels. Unit testing involves testing individual units or components of the software to ensure they work as expected. Integration testing is checking the integration between different components works together as expected. System testing involves testing the entire system to ensure that it meets the business requirements and functional specifications. Acceptance testing is done at the highest level and involves ensuring that the system meets the user's needs and expectations.

In Agile, testing is seamlessly integrated throughout development. Unit testing by developers ensures individual components function as intended, while integration testing validates their interactions. System testing assesses the entire system, and acceptance testing ensures alignment with business requirements. Various test types include functional, non-functional, regression, UI, and exploratory testing. Automation, using tools like Selenium and JUnit, is emphasized for efficiency. Agile's iterative approach promotes continuous testing within short development cycles, fostering collaboration and proactive quality assurance.

Agile test levels ensure thorough software testing at different stages: unit (individual components), integration (collaboration), system (entire system), and acceptance (end-user validation). These levels adapt to the iterative nature of agile, enhancing overall product quality.

Test driven approach can be taken up by adding maximum unit testing test cases using tools like selenium nunit , junit.. etc, parallely manual test cases should be created and reviewed for the story ,once the deliverables are ready to test the Dev demo should be conducted to get early feedbacks from the stakeholders , Functional test approach either by automating test cases with tools like selenium for Ui and Api testing can be conducted with tools like postman or SoapUi and automated Regression suite should be run on Dev env as well as staging env for integration test, Non functional test can be conducted every release once code is freezed.

In agile, the adaptability of test types reflects the dynamic nature of software development. From ensuring functionality through functional testing to exploring system behavior with exploratory testing, each type serves a specific purpose. The flexibility to tailor these tests to project needs, alongside tools like Postman, JMeter, and Selenium, contributes to an agile testing approach that aligns closely with evolving requirements, fostering resilience and reliability in the software.

Testing is the process of executing a program to find errors. To make our software perform well it should be error-free. If testing is done successfully it will remove all the errors from the software. There are basically 10 types of Testing in general. Unit Testing Integration Testing System Testing Functional Testing Acceptance Testing Smoke Testing Regression Testing Performance Testing Security Testing User Acceptance Testing

Don't get bogged down with massive amounts of documentation. But and its a bug but please still document when it clearly adds value such as defect reports.

Working software as the primary measure of progress Self-organizing teams for optimal results Early and continuous testing throughout the development cycle Daily collaboration among all team members Continuous technical improvement and good design