Test long running processes

As long as the application under test is expected to terminate by itself, it is fine to use .execute().assertSuccess() as we did in several examples above.

On the other hand, when testing some long running process, such as application server or a docker container, you typically want to

Run the command starting the service
Await it being up and running
Perform some assertions
Shut down the service

Here is a commented snippet suitable for such situations:

import org.cliassured.CliAssured;
import org.cliassured.CommandProcess;
import org.cliassured.await.Await;
import org.cliassured.await.Await.LineAwait;
...

// Define an Await that will wait for first line on stdout matching the given regular expression
final LineAwait<Integer> awaitPort = Await
        .lineMatching("listening on port: (\\d+)")
        .map(Integer::parseInt); // transform the string matching the (\\d+) group to int

try (CommandProcess proc = CliAssured.command(/* Your command for starting the server comes here ... */)
            .then()
                .stdout()
                    .await(awaitPort)
                    .log()
                .stderr()
                    .log()
            .start()) {

    // Wait at most for 10 seconds for the port message on stdout
    int port = awaitPort.await(Duration.ofSeconds(10));

    // Now the server has started - we can perform some tests requiring the port
    RestAssured.get("http://localhost:" + port)
            .then()
            .statusCode(200);

} // proc gets auto-closed here

The default auto-close behavior of CommandProcess can be characterized as follows:

java.lang.Process.destroy() is called on the main process
On Java 9+, any descendant processes returned by process.toHandle().descendants() are also closed using java.lang.ProcessHandle.destroy()
On Java 8, only the main process is destroyed

Use the following methods to customize the auto-closing behavior of org.cliassured.CommandProcess:

CliAssured.command(…).autoCloseWithoutDescendants() to avoid closing descendant processes
CliAssured.command(…).autoCloseForcibly() to close the main and descendant processes using java.lang.Process.destroyForcibly() and java.lang.ProcessHandle.destroyForcibly() respectively
CliAssured.command(…).autoCloseTimeout(Duration) to wait at most for the specified Duration after destroy() or destroyForcibly() was called on main process and possibly on its descendant processes until the main process reports its state as terminated.