zunit

Generate and run zunit tests for a java-cli-app project using $ARGUMENTS. Apply all rules below strictly.

What is zunit

zunit is a zero-dependency test runner. It discovers *Test.java source files and runs each directly via java --source 25. No compilation step, no JUnit, no framework.

Test Convention

• Test files: name ends with Test.java, placed in test/ directory
• Each test file is a self-contained Java source script with void main()
• Tests run via java --source 25 --class-path <classpath>
• Failure: any thrown exception or non-zero exit = failed
• Success: clean exit with code 0
• All test files run concurrently in separate JVMs

Test File Structure

Every test file follows this pattern:

void main() {
    // arrange
    var input = ...;

    // act
    var result = SomeClass.someMethod(input);

    // assert
    assert expected.equals(result) : "expected %s but got %s".formatted(expected, result);
}

Assertion Style

• No assertion libraries — use the built-in assert statement; zunit runs every test with -ea
• Always attach a descriptive message including expected and actual values: assert condition : message
• One test file can contain multiple assertions — the first failure stops the file
• For testing exceptions, use try/catch and throw AssertionError explicitly:

void main() {
    try {
        SomeClass.methodThatShouldFail(badInput);
        throw new AssertionError("expected exception was not thrown");
    } catch (IllegalArgumentException expected) {
        // success
    }
}

Caveat: assert only executes with assertions enabled. Running a test file directly requires the flag: java -ea FooTest.java.

Test Discovery for java-cli-app Projects

Directory Layout

project-root/
├── src/main/java/          # main source (compiled by zb)
├── test/                   # zunit test sources
│   ├── SomethingTest.java
│   └── AnotherTest.java
├── zbo/app.jar             # zb output (auto-detected as classpath)
└── .zb                     # zb config