[FIXED] how to stop our mocked MongoDb in applicationContext for just 1 negative testCase?

Issue

How to simulate "DB down" condition for negative integration test of application ?

Have to write the negative integration test of application with mocked Db in context as follows:

    @Bean
public MongoDb mongoDb() throws URISyntaxException {
        return new MongoDb(new URI(String.format("mongodb://localhost:%s/", mongoDbPort)), databaseName);
    }

The class MongoDb being:

public class MongoDb {

    private final MongoClient mongo;
    private final String databaseName;

    public MongoDb(URI url, String databaseName) {
        log.debug("Mongodb url:" + url);
        mongo = new MongoClient(url.getHost(), url.getPort());
        this.databaseName = databaseName;
    }

    @PreDestroy
    public void shutdown() {
        log.debug("Tearing down mongo.");
        final MongoDatabase db = mongo.getDatabase(databaseName);
        if (db != null) {
            db.drop();
        }
    }
}

How to simulate "DB down" condition here for negative test case (with same context bean)?

Tried Stopping the mongo in my testCase: mongoDb.getMongo().dropDatabase(dbnameValue); but it didn't raise any exception

Any clue is appreciated!

Solution

There is an old post about using PowerMockito with MongoDB: Unit testing with MongoDB

The API has changed but the way of mocking should still be usable.

MongoClient mongo = PowerMockito.mock(MongoClient.class);
PowerMockito.when(mongo.getDatabase("DBDownForTest")).doThrow(new MongoClientException("Test DB is down"));

This will only work if you are calling getDatabase with the argument DBDownForTest. Otherwise you will have to use anyString().

Maybe you can even use Mockito without PowerMockito with current MongoDB versions.

Answered By - Jens Dibbern
Answer Checked By - Clifford M. (JavaFixing Volunteer)