Zero-dependency, single-file Java test runner. Discovers *Test.java and *IT.java source files and runs each directly via java --source 25 in a separate process. No compilation step, no JUnit, no build tool required — just run zunit and go. Each test gets its own JVM — full execution isolation with zero shared state.

zunit

• Unit tests: name ends with Test.java
• Integration tests: name ends with IT.java — run after unit tests
• Each file is a self-contained Java source script with void main()
• Execution isolation: each test runs in its own JVM process — no shared state, no interference between tests
• Failure: any thrown exception or non-zero exit = failed

Example test:

import java.util.Objects;
void main() {
 var greeting = Greeter.greet("World");
 assert Objects.equals("Hello, World!", greeting) : "expected 'Hello, World!' but got: " + greeting;
}

zunit [options]

1. src/test/java/ — Maven layout
2. test/ — simple layout
3. . — fallback

1. .zb config (jar.dir + jar.file.name) — zb configuration
2. zbo/app.jar — zb default
3. target/classes — Maven output
4. classes/ — simple layout
5. . — fallback

zunit # auto-detect and run all tests
zunit -cp:zbo/app.jar # explicit classpath
zunit -tp:test/ # explicit test source path
zunit -verbose # show debug output

zb && zunit

zunit reads the .zb configuration file (if present) to resolve the JAR path from jar.dir and jar.file.name. Falls back to zbo/app.jar if .zb is absent.

A zunit skill is available for AI-assisted generation and execution of zunit tests.

• bce.design — Boundary-Control-Entity architecture
• zcl — Zero-dependency Colour Logger
• zcfg — Zero-dependency Configuration Utility
• zb — Zero-dependency Builder
• airails.dev — AI-powered Development