Software Testing and JUnit and Best Practices

Software Testing and JUnit and Best Practices

• 1.
  Software Testing Tung ThanhNguyen, PhD Department of Computer Science Fulbright University Vietnam
• 2.
  Introduction to SoftwareTesting • Software testing ensures software quality • Detecting bugs and verifying functionality. • Validating that software meets requirements and behaves as expected. • JUnit is a popular testing framework for Java applications.
• 3.
  Types of SoftwareTesting • Manual Testing - Performed by humans without automation. • Automated Testing - Uses software tools to run tests automatically. • Unit Testing - Tests individual components of code. • Integration Testing - Verifies interactions between components. • System Testing - Tests all system’s functionality. • User Acceptance Testing - Validates software requirements from user perspective.
• 4.
  Junit – Testingframrwork for Java • Provides a structured way to write and execute tests. • Supports test automation. • Integrates well with build tools (e.g., Maven, Gradle). • Helps ensure code reliability and maintainability.
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  Installing JUnit • AddJUnit dependency to Maven: <dependency> <groupId>org.junit.jupiter</groupId> <artifactId>junit-jupiter-api</artifactId> <version>5.7.1</version> <scope>test</scope> </dependency>
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  Writing a BasicJUnit Test import org.junit.jupiter.api.Test; import static org.junit.jupiter.api.Assertions.*; class CalculatorTest { @Test void testAddition() { assertEquals(5, 2 + 3); } }
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  JUnit Annotations • @Test- Marks a test method. • @BeforeEach - Runs before each test. • @AfterEach - Runs after each test. • @BeforeAll - Runs once before all tests. • @AfterAll - Runs once after all tests.
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  Setup and TeardownMethods import org.junit.jupiter.api.*; class TestLifecycle { @BeforeEach void setUp() { System.out.println("Setting up test"); } @AfterEach void tearDown() { System.out.println("Cleaning up test"); } @Test void exampleTest() { assertTrue(true); } }
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  Testing Exceptions import staticorg.junit.jupiter.api.Assertions.*; class ExceptionTest { @Test void testException() { assertThrows(ArithmeticException.class, () -> { int result = 10 / 0; }); } }
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  Parameterized Tests import org.junit.jupiter.params.ParameterizedTest; importorg.junit.jupiter.params.provider.ValueSource; class ParameterizedExample { @ParameterizedTest @ValueSource(ints = {1, 2, 3}) void testNumbers(int number) { assertTrue(number > 0); } }
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  Test Coverage Metrics •Statement Coverage - Tests if each line is executed. • Branch Coverage - Ensures all branches in control structures execute. • Path Coverage - Tests all possible paths in a function.
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  Assertions in JUnit importstatic org.junit.jupiter.api.Assertions.*; class AssertionsExample { @Test void testAssertions() { assertEquals(4, 2 + 2); assertNotNull("Hello"); assertTrue(5 > 3); } }
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  Running JUnit Tests •Use mvn test for Maven projects. • Use gradle test for Gradle projects. • Run tests directly in IDE (e.g., IntelliJ, Eclipse).
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  Continuous Integration withJUnit • Use Jenkins, GitHub Actions, or GitLab CI/CD. • Automate test execution on code commits.
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  Handling Test Failures •Check error messages and stack traces. • Debug using breakpoints. • Improve test reliability with proper setup.
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  Best Practices inUnit Testing • Keep tests independent. • Use meaningful test names. • Cover edge cases. • Run tests frequently.
• 17.
  Summary • Software testingis crucial for code quality. • JUnit simplifies unit testing. • Use assertions and CI/CD for robust testing.