/*
* Copyright 2002-2016 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.test.context.junit4.rules;
import java.lang.reflect.Field;
import java.lang.reflect.Modifier;
import java.util.Arrays;
import java.util.Map;
import java.util.Optional;
import java.util.concurrent.ConcurrentHashMap;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.junit.Rule;
import org.junit.rules.TestRule;
import org.junit.runner.Description;
import org.junit.runners.model.Statement;
import org.springframework.test.context.TestContextManager;
import org.springframework.test.context.junit4.statements.ProfileValueChecker;
import org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks;
import org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks;
import org.springframework.util.Assert;
import org.springframework.util.ClassUtils;
/**
* {@code SpringClassRule} is a custom JUnit {@link TestRule} that supports
* <em>class-level</em> features of the <em>Spring TestContext Framework</em>
* in standard JUnit tests by means of the {@link TestContextManager} and
* associated support classes and annotations.
*
* <p>In contrast to the {@link org.springframework.test.context.junit4.SpringJUnit4ClassRunner
* SpringJUnit4ClassRunner}, Spring's rule-based JUnit support has the advantage
* that it is independent of any {@link org.junit.runner.Runner Runner} and
* can therefore be combined with existing alternative runners like JUnit's
* {@code Parameterized} or third-party runners such as the {@code MockitoJUnitRunner}.
*
* <p>In order to achieve the same functionality as the {@code SpringJUnit4ClassRunner},
* however, a {@code SpringClassRule} must be combined with a {@link SpringMethodRule},
* since {@code SpringClassRule} only supports the class-level features of the
* {@code SpringJUnit4ClassRunner}.
*
* <h3>Example Usage</h3>
* <pre><code> public class ExampleSpringIntegrationTest {
*
* @ClassRule
* public static final SpringClassRule springClassRule = new SpringClassRule();
*
* @Rule
* public final SpringMethodRule springMethodRule = new SpringMethodRule();
*
* // ...
* }</code></pre>
*
* <p>The following list constitutes all annotations currently supported directly
* or indirectly by {@code SpringClassRule}. <em>(Note that additional annotations
* may be supported by various
* {@link org.springframework.test.context.TestExecutionListener TestExecutionListener} or
* {@link org.springframework.test.context.TestContextBootstrapper TestContextBootstrapper}
* implementations.)</em>
*
* <ul>
* <li>{@link org.springframework.test.annotation.ProfileValueSourceConfiguration @ProfileValueSourceConfiguration}</li>
* <li>{@link org.springframework.test.annotation.IfProfileValue @IfProfileValue}</li>
* </ul>
*
* <p><strong>NOTE:</strong> As of Spring Framework 4.3, this class requires JUnit 4.12 or higher.
*
* @author Sam Brannen
* @author Philippe Marschall
* @since 4.2
* @see #apply(Statement, Description)
* @see SpringMethodRule
* @see org.springframework.test.context.TestContextManager
* @see org.springframework.test.context.junit4.SpringJUnit4ClassRunner
*/
public class SpringClassRule implements TestRule {
private static final Log logger = LogFactory.getLog(SpringClassRule.class);
/**
* Cache of {@code TestContextManagers} keyed by test class.
*/
private static final Map<Class<?>, TestContextManager> testContextManagerCache =
new ConcurrentHashMap<>(64);
static {
Assert.state(ClassUtils.isPresent("org.junit.internal.Throwables", SpringClassRule.class.getClassLoader()),
"SpringClassRule requires JUnit 4.12 or higher.");
}
/**
* Apply <em>class-level</em> features of the <em>Spring TestContext
* Framework</em> to the supplied {@code base} statement.
* <p>Specifically, this method retrieves the {@link TestContextManager}
* used by this rule and its associated {@link SpringMethodRule} and
* invokes the {@link TestContextManager#beforeTestClass() beforeTestClass()}
* and {@link TestContextManager#afterTestClass() afterTestClass()} methods
* on the {@code TestContextManager}.
* <p>In addition, this method checks whether the test is enabled in
* the current execution environment. This prevents classes with a
* non-matching {@code @IfProfileValue} annotation from running altogether,
* even skipping the execution of {@code beforeTestClass()} methods
* in {@code TestExecutionListeners}.
* @param base the base {@code Statement} that this rule should be applied to
* @param description a {@code Description} of the current test execution
* @return a statement that wraps the supplied {@code base} with class-level
* features of the Spring TestContext Framework
* @see #getTestContextManager
* @see #withBeforeTestClassCallbacks
* @see #withAfterTestClassCallbacks
* @see #withProfileValueCheck
* @see #withTestContextManagerCacheEviction
*/
@Override
public Statement apply(Statement base, Description description) {
Class<?> testClass = description.getTestClass();
if (logger.isDebugEnabled()) {
logger.debug("Applying SpringClassRule to test class [" + testClass.getName() + "]");
}
validateSpringMethodRuleConfiguration(testClass);
TestContextManager testContextManager = getTestContextManager(testClass);
Statement statement = base;
statement = withBeforeTestClassCallbacks(statement, testContextManager);
statement = withAfterTestClassCallbacks(statement, testContextManager);
statement = withProfileValueCheck(statement, testClass);
statement = withTestContextManagerCacheEviction(statement, testClass);
return statement;
}
/**
* Wrap the supplied {@link Statement} with a {@code RunBeforeTestClassCallbacks} statement.
* @see RunBeforeTestClassCallbacks
*/
private Statement withBeforeTestClassCallbacks(Statement next, TestContextManager testContextManager) {
return new RunBeforeTestClassCallbacks(next, testContextManager);
}
/**
* Wrap the supplied {@link Statement} with a {@code RunAfterTestClassCallbacks} statement.
* @see RunAfterTestClassCallbacks
*/
private Statement withAfterTestClassCallbacks(Statement next, TestContextManager testContextManager) {
return new RunAfterTestClassCallbacks(next, testContextManager);
}
/**
* Wrap the supplied {@link Statement} with a {@code ProfileValueChecker} statement.
* @see ProfileValueChecker
*/
private Statement withProfileValueCheck(Statement next, Class<?> testClass) {
return new ProfileValueChecker(next, testClass, null);
}
/**
* Wrap the supplied {@link Statement} with a {@code TestContextManagerCacheEvictor} statement.
* @see TestContextManagerCacheEvictor
*/
private Statement withTestContextManagerCacheEviction(Statement next, Class<?> testClass) {
return new TestContextManagerCacheEvictor(next, testClass);
}
/**
* Throw an {@link IllegalStateException} if the supplied {@code testClass}
* does not declare a {@code public SpringMethodRule} field that is
* annotated with {@code @Rule}.
*/
private static void validateSpringMethodRuleConfiguration(Class<?> testClass) {
Field ruleField = findSpringMethodRuleField(testClass).orElseThrow(() ->
new IllegalStateException(String.format(
"Failed to find 'public SpringMethodRule' field in test class [%s]. " +
"Consult the javadoc for SpringClassRule for details.", testClass.getName())));
Assert.state(ruleField.isAnnotationPresent(Rule.class), () -> String.format(
"SpringMethodRule field [%s] must be annotated with JUnit's @Rule annotation. " +
"Consult the javadoc for SpringClassRule for details.", ruleField));
}
private static Optional<Field> findSpringMethodRuleField(Class<?> testClass) {
return Arrays.stream(testClass.getFields())
.filter(field -> !Modifier.isStatic(field.getModifiers()))
.filter(field -> Modifier.isPublic(field.getModifiers()))
.filter(field -> SpringMethodRule.class.isAssignableFrom(field.getType()))
.findFirst();
}
/**
* Get the {@link TestContextManager} associated with the supplied test class.
* @param testClass the test class to be managed; never {@code null}
*/
static TestContextManager getTestContextManager(Class<?> testClass) {
Assert.notNull(testClass, "testClass must not be null");
return testContextManagerCache.computeIfAbsent(testClass, TestContextManager::new);
}
private static class TestContextManagerCacheEvictor extends Statement {
private final Statement next;
private final Class<?> testClass;
TestContextManagerCacheEvictor(Statement next, Class<?> testClass) {
this.next = next;
this.testClass = testClass;
}
@Override
public void evaluate() throws Throwable {
try {
next.evaluate();
}
finally {
testContextManagerCache.remove(testClass);
}
}
}
}