core/spi/src/test/java/org/qi4j/spi/metrics/DefaultMetricsTest.java

/*
 * Copyright (c) 2012, Niclas Hedhman. All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file Expect in compliance with the License.
 *
 *     You may obtain a copy of the License at
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.qi4j.spi.metrics;

import java.util.concurrent.TimeUnit;
import org.junit.Test;
import org.qi4j.api.metrics.MetricsCounter;
import org.qi4j.api.metrics.MetricsCounterFactory;
import org.qi4j.api.metrics.MetricsGauge;
import org.qi4j.api.metrics.MetricsGaugeFactory;
import org.qi4j.api.metrics.MetricsHealthCheck;
import org.qi4j.api.metrics.MetricsHealthCheckFactory;
import org.qi4j.api.metrics.MetricsHistogram;
import org.qi4j.api.metrics.MetricsHistogramFactory;
import org.qi4j.api.metrics.MetricsMeter;
import org.qi4j.api.metrics.MetricsMeterFactory;
import org.qi4j.api.metrics.MetricsProvider;
import org.qi4j.api.metrics.MetricsTimer;
import org.qi4j.api.metrics.MetricsTimerFactory;

import static org.junit.Assert.assertNull;

public class DefaultMetricsTest
{
    @Test
    public void givenMetricsProviderWithoutSupportForCounterWhenRequestingCounterExpectDefaultNullImplementation()
    {
        MetricsProvider underTest = new MetricsProviderAdapter();
        MetricsCounterFactory factory = underTest.createFactory( MetricsCounterFactory.class );
        MetricsCounter test = factory.createCounter( getClass(), "test" );
        test.increment();
        test.decrement();
    }

    @Test
    public void givenMetricsProviderWithoutSupportForGaugeWhenRequestingGaugeExpectDefaultNullImplementation()
    {
        MetricsProvider underTest = new MetricsProviderAdapter();
        MetricsGaugeFactory factory = underTest.createFactory( MetricsGaugeFactory.class );
        MetricsGauge<Long> test = factory.registerGauge( getClass(), "test", new MetricsGauge<Long>()
        {
            @Override
            public Long value()
            {
                return System.currentTimeMillis();
            }
        } );
        assertNull( test.value() );
    }

    @Test
    public void givenMetricsProviderWithoutSupportForHealthCheckWhenRequestingHealthCheckExpectDefaultNullImplementation()
        throws Exception
    {
        MetricsProvider underTest = new MetricsProviderAdapter();
        MetricsHealthCheckFactory factory = underTest.createFactory( MetricsHealthCheckFactory.class );
        MetricsHealthCheck test = factory.registerHealthCheck( getClass(), "test", new MetricsHealthCheck()
        {
            @Override
            public Result check()
                throws Exception
            {
                throw new RuntimeException( "Not healthy!!!" );
            }
        } );
        test.check(); // Should not throw an exception, as it should have been replaced by a null implementation.
    }

    @Test
    public void givenMetricsProviderWithoutSupportForHistogramWhenRequestingHistogramExpectDefaultNullImplementation()
    {
        MetricsProvider underTest = new MetricsProviderAdapter();
        MetricsHistogramFactory factory = underTest.createFactory( MetricsHistogramFactory.class );
        MetricsHistogram test = factory.createHistogram( getClass(), "test" );
        test.update( 5L );
        test.update( 5L );
        test.update( 5L );
    }

    @Test
    public void givenMetricsProviderWithoutSupportForMeterWhenRequestingMeterExpectDefaultNullImplementation()
    {
        MetricsProvider underTest = new MetricsProviderAdapter();
        MetricsMeterFactory factory = underTest.createFactory( MetricsMeterFactory.class );
        MetricsMeter test = factory.createMeter( getClass(), "test", "niclas", TimeUnit.MILLISECONDS );
        test.mark();
        test.mark();
        test.mark();
    }

    @Test
    public void givenMetricsProviderWithoutSupportForTimerWhenRequestingTimerExpectDefaultNullImplementation()
    {
        MetricsProvider underTest = new MetricsProviderAdapter();
        MetricsTimerFactory factory = underTest.createFactory( MetricsTimerFactory.class );
        MetricsTimer test = factory.createTimer( getClass(), "test", TimeUnit.MILLISECONDS, TimeUnit.DAYS );
        test.start().stop();
    }
}