1 /* 2 * Copyright 2018, OpenCensus Authors 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package io.opencensus.metrics; 18 19 import static com.google.common.truth.Truth.assertThat; 20 21 import io.opencensus.metrics.export.ExportComponent; 22 import org.junit.Rule; 23 import org.junit.Test; 24 import org.junit.rules.ExpectedException; 25 import org.junit.runner.RunWith; 26 import org.junit.runners.JUnit4; 27 28 /** Unit tests for {@link Metrics}. */ 29 @RunWith(JUnit4.class) 30 public class MetricsTest { 31 @Rule public ExpectedException thrown = ExpectedException.none(); 32 33 @Test loadMetricsComponent_UsesProvidedClassLoader()34 public void loadMetricsComponent_UsesProvidedClassLoader() { 35 final RuntimeException toThrow = new RuntimeException("UseClassLoader"); 36 thrown.expect(RuntimeException.class); 37 thrown.expectMessage("UseClassLoader"); 38 Metrics.loadMetricsComponent( 39 new ClassLoader() { 40 @Override 41 public Class<?> loadClass(String name) { 42 throw toThrow; 43 } 44 }); 45 } 46 47 @Test loadMetricsComponent_IgnoresMissingClasses()48 public void loadMetricsComponent_IgnoresMissingClasses() { 49 ClassLoader classLoader = 50 new ClassLoader() { 51 @Override 52 public Class<?> loadClass(String name) throws ClassNotFoundException { 53 throw new ClassNotFoundException(); 54 } 55 }; 56 assertThat(Metrics.loadMetricsComponent(classLoader).getClass().getName()) 57 .isEqualTo("io.opencensus.metrics.MetricsComponent$NoopMetricsComponent"); 58 } 59 60 @Test defaultExportComponent()61 public void defaultExportComponent() { 62 assertThat(Metrics.getExportComponent()) 63 .isInstanceOf(ExportComponent.newNoopExportComponent().getClass()); 64 } 65 66 @Test defaultMetricRegistry()67 public void defaultMetricRegistry() { 68 assertThat(Metrics.getMetricRegistry()) 69 .isInstanceOf(MetricRegistry.newNoopMetricRegistry().getClass()); 70 } 71 } 72