Testing and Debugging

This guide provides information on how to test and debug OpenRocket. It covers unit testing, debugging techniques, and best practices for ensuring code quality.

Unit Testing

OpenRocket uses JUnit 5 (Jupiter) as its testing framework. The test code is organized in separate directories from the main code:

  • core/src/test/java - Tests for the core functionality

  • swing/src/test/java - Tests for the swing UI components

Running Tests

You can run tests using Gradle:

# Run all tests
./gradlew test

# Run tests for a specific module
./gradlew core:test
./gradlew swing:test

# Run a specific test class
./gradlew core:test --tests "info.openrocket.core.util.MathUtilTest"

Test Structure

Tests in OpenRocket follow standard JUnit conventions:

  • Test classes are named with a Test suffix (e.g., MathUtilTest)

  • Test methods are annotated with @Test

  • Many tests extend BaseTestCase which provides common functionality

Example Test

Here’s a simple example of a test class:

package info.openrocket.core.util;

import org.junit.jupiter.api.Test;
import static org.junit.jupiter.api.Assertions.*;

public class ExampleTest extends BaseTestCase {

    @Test
    public void testSomeFeature() {
        // Arrange
        SomeClass instance = new SomeClass();

        // Act
        int result = instance.someMethod();

        // Assert
        assertEquals(42, result);
    }
}

Writing Good Tests

When writing tests for OpenRocket, follow these guidelines:

  1. Test one thing per test method

  2. Use descriptive test method names that explain what is being tested

  3. Structure tests with Arrange-Act-Assert pattern

  4. Mock external dependencies when appropriate

  5. Test edge cases and error conditions

  6. Keep tests independent of each other

Code Coverage

OpenRocket uses the JaCoCo plugin to track and enforce test coverage. Coverage verification is integrated into the build process to ensure code quality.

  • Core module: minimum 60% coverage threshold

  • Swing module: threshold currently disabled (0%) due to limited test coverage

  • Aggregate reports: generated via the jacocoRootReport task

If coverage thresholds are not met, JAR packaging will fail. This prevents deployment of code that does not meet the required quality standards.

Usage

To generate coverage reports:

./gradlew test jacocoRootReport

To build with coverage verification:

./gradlew build

Coverage verification runs automatically during JAR packaging. Detailed HTML reports are available under build/reports/jacoco/ (aggregate report), core/build/reports/jacoco/, and swing/build/reports/jacoco/ for review. Additionally, a GitHub Action publishes coverage reports for easier tracking in CI.

Debugging

The most powerful debugging tool is your IDE’s debugger. Both IntelliJ IDEA and Eclipse provide excellent debugging capabilities:

  1. Set breakpoints in your code

  2. Run OpenRocket in debug mode

  3. Inspect variables and step through code execution