Assume NG -- Assumptions for TestNG

Using Assume NG it becomes possible to add JUnit-like assumptions to TestNG.

Usage

Assume NG works using the @Assumption annotation and the AssumptionListener.

The @Assumption annotation is defined on a @Test method, and calls out to one or more assumption methods which decide whether or not the @Test annotated method needs to run in the current context. Only if all of the assumption methods pass, the @Test method will actually be invoked, otherwise it will be marked as skipped.

The AssumptionListener scans for @Assumption annotations and handles the actual invocation of the assumption method.

The assumption method should have the following signature

public boolean checkWhetherXHolds() { ... }

A simple usage example is:

@Listeners(AssumptionListener.class)
public class WeatherTest {
    @Test
    @Assumption(methods = "assumeWeatherIsNice")
    public void shouldNotRunWhenItsRaining() {
        // Do some stuff, like going to the beach...
    }

    public boolean assumeWeatherIsNice() {
        // check the weather bulletin...
    }
}

"Real world" use case

public class HostFactoryItest {
    @Factory
    public Object[] createTestInstances() {
        Object[] instances = new Object[6];
        object[0] = new HostItest("localhost", "local");
        object[1] = new HostItest("unix-host", "sftp");
        object[2] = new HostItest("unix-host", "ssh");
        object[3] = new HostItest("windows-host", "sftp");
        object[4] = new HostItest("windows-host", "cifs-telnet");
        object[5] = new HostItest("windows-host", "cifs-winrm");
    }
}

@Listeners(AssumptionListener.class)
public class HostItest() {
    private String host;
    private String protocol;

    public HostItest(String host, String protocol) {
        ...
    }

    @Test
    @Assumption(methods = "notLocal")
    public void shouldNotConnectUsingWrongPassword() {
        ...
    }

    @Test
    public void shouldGetFileFromHost() {
        ...
    }

    ...more tests...

    public boolean notLocal() {
        return !this.host.equals("localhost");
    }
}