zelador

zelador

A minimalist JUnit 5 extension to register AutoCloseable resources that will be destroyed after tests finish executing.

Features

• Written in pure Java 21.
• OSGi ready.
• JPMS ready.
• ISC license.
• High-coverage automated test suite.

Motivation

For whatever reason, JUnit 5 does not include any utility to register per-test resources and automatically have them cleaned up.

The zelador package provides a tiny JUnit 5 extension that allows for registering AutoCloseable objects that must be closed after tests finish executing.

Building

$ mvn clean verify

Usage

Annotate your test suite with @ExtendWith(ZeladorExtension.class). This will allow tests to get access to an injected CloseableResourcesType instance that can be used to register resources to be closed.

@ExtendWith(ZeladorExtension.class)
public final class ExampleTest
{
  @Test
  public void test0(
    final CloseableResourcesType resources)
  {
    var output = resources.addPerTestResource(Files.newOutputStream(...));
    ...
  }

  @Test
  public void test1(
    final CloseableResourcesType resources)
  {
    var output = resources.addPerTestClassResource(Files.newOutputStream(...));
    ...
  }
}

Resources added with addPerTestResource will be closed after the individual test has finished (as if it had been closed in an @AfterEach method).

Resources added with addPerTestClassResource will be closed after all tests in the class have finished (as if it had been closed in an @AfterAll method).

AutoCloseable is a functional interface and, as such, it's trivial to pass objects to the CloseableResourcesType class that do not implement AutoCloseable by simply using a method reference:

class NotReallyCloseable {
  public void finish() { ... }
}

NotReallyCloseable x;

resources.addPerTestResource(x::finish);