What is system testing?

System testing is the level of testing that verifies a completed and integrated system against specified functional and non-functional requirements.

Goals of system testing:

• Determine whether the system meets business requirements.
• Verify the interaction of all system components.
• Ensure overall stability and performance of the system.

System testing is usually performed on a fully integrated system after module and integration testing. It is a "black box" testing, meaning the tester does not have access to the internal code or structure of the system.

Types of system testing:

• Functional Testing: Checking system functions against requirements.
• Non-functional Testing: Checking aspects like performance, security, reliability, usability, etc.
  • Performance Testing: Measuring speed, scalability, and stability under load.
  • Security Testing: Checking for vulnerabilities and threats.
  • Reliability Testing: Assessing the system's ability to perform its functions over a period without failures.
  • Usability Testing: Evaluating how easy and intuitive it is for users to interact with the system.
  • Compatibility Testing: Checking the system's operation in different environments (various operating systems, browsers, etc.).

Example of a test scenario (pseudocode):

# Scenario: User login verification
# Steps:
# 1. Open login page.
# 2. Enter valid username.
# 3. Enter valid password.
# 4. Click "Login" button.
# Expected result: User is successfully redirected to the main page.

def test_user_login_successful():
    open_login_page()
    enter_username("valid_user")
    enter_password("valid_password")
    click_login_button()
    assert current_page_is("main_page")