/*
* Copyright 2015-2016 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except 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.springframework.cloud.stream.test.junit;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.junit.Assume;
import org.junit.Rule;
import org.junit.rules.TestRule;
import org.junit.runner.Description;
import org.junit.runners.model.Statement;
import org.springframework.util.Assert;
import static org.junit.Assert.fail;
/**
* Abstract base class for JUnit {@link Rule}s that detect the presence of some external
* resource. If the resource is indeed present, it will be available during the test
* lifecycle through {@link #getResource()}. If it is not, tests will either fail or be
* skipped, depending on the value of system property
* {@value #SCS_EXTERNAL_SERVERS_REQUIRED}.
*
* @author Eric Bottard
* @author Gary Russell
*/
public abstract class AbstractExternalResourceTestSupport<R> implements TestRule {
public static final String SCS_EXTERNAL_SERVERS_REQUIRED = "SCS_EXTERNAL_SERVERS_REQUIRED";
protected R resource;
private String resourceDescription;
protected final Log logger = LogFactory.getLog(getClass());
protected AbstractExternalResourceTestSupport(String resourceDescription) {
Assert.hasText(resourceDescription, "resourceDescription is required");
this.resourceDescription = resourceDescription;
}
@Override
public Statement apply(final Statement base, Description description) {
try {
obtainResource();
}
catch (Exception e) {
maybeCleanup();
return failOrSkip(e);
}
return new Statement() {
@Override
public void evaluate() throws Throwable {
try {
base.evaluate();
}
finally {
try {
cleanupResource();
}
catch (Exception ignored) {
logger.warn("Exception while trying to cleanup proper resource",
ignored);
}
}
}
};
}
private Statement failOrSkip(final Exception e) {
String serversRequired = System.getenv(SCS_EXTERNAL_SERVERS_REQUIRED);
if ("true".equalsIgnoreCase(serversRequired)) {
logger.error(resourceDescription + " IS REQUIRED BUT NOT AVAILABLE", e);
fail(resourceDescription + " IS NOT AVAILABLE");
// Never reached, here to satisfy method signature
return null;
}
else {
logger.error(resourceDescription + " IS NOT AVAILABLE, SKIPPING TESTS", e);
return new Statement() {
@Override
public void evaluate() throws Throwable {
Assume.assumeTrue("Skipping test due to " + resourceDescription
+ " not being available " + e, false);
}
};
}
}
private void maybeCleanup() {
if (resource != null) {
try {
cleanupResource();
}
catch (Exception ignored) {
logger.warn("Exception while trying to cleanup failed resource", ignored);
}
}
}
public R getResource() {
return resource;
}
/**
* Perform cleanup of the {@link #resource} field, which is guaranteed to be non null.
*
* @throws Exception any exception thrown by this method will be logged and swallowed
*/
protected abstract void cleanupResource() throws Exception;
/**
* Try to obtain and validate a resource. Implementors should either set the
* {@link #resource} field with a valid resource and return normally, or throw an
* exception.
*/
protected abstract void obtainResource() throws Exception;
}