This build will always fail because it has 2 examples of failing tests: one because of a defect in the SUT (system under test), and one because of an error in the test itself.

Learning objectives

• Simple hello world example
• Experience with Git source code management
• Building with Gradle
• Automated unit testing with JUnit 5
• Continuous integration with GitHub Actions

System requirements

• Java 21 SDK or later (Java 21 LTS release recommended)
• Gradle (included via wrapper - no separate installation required)

Your Codespace for this repo will already include these tools.

When working on a local workstation, you can conveniently install Java using SDKMAN!.

Migration Note

This project has been migrated from Maven to Gradle 9.3.0. For detailed migration information, see doc/GRADLE-MIGRATION.md.

Running the application

Without command-line arguments:

$ ./gradlew run

You can also run the application with specific command-line arguments:

$ ./gradlew run --args="arg1 arg2 arg3"

Running the tests

To compile and run the tests:

$ ./gradlew test

Generating the test coverage report

The coverage report is automatically generated when you run tests. To view it:

$ ./gradlew test jacocoTestReport

You can view the formatted HTML version of the report. In your Codespace or other VS Code instance, locate

build/reports/jacoco/test/html/index.html

then right-click and choose "show preview" from the context menu. (This requires the Live Preview extension for VS Code to be installed.)

You can also open the report locally through a web browser or on the command line.

On macOS:

$ open build/reports/jacoco/test/html/index.html

On Linux:

$ xdg-open build/reports/jacoco/test/html/index.html

On Windows: please let me know if you know how to do this from the WSL command line. Otherwise you can open the index file in your web browser or VS Code.

Running the application outside Gradle

First, create the standalone executable JAR file containing all dependencies:

$ ./gradlew shadowJar

This creates a "fat JAR" that can be executed anywhere Java is installed.

The JAR can be run on any platform (Linux, macOS, Windows) with:

$ java -jar build/libs/hello-java-1.0-SNAPSHOT-all.jar arg1 arg2 arg3

No classpath configuration is needed - all dependencies are bundled inside the JAR.