Package org.junit.runners

Source Code of org.junit.runners.BlockJUnit4ClassRunner

package org.junit.runners;

import static org.junit.internal.runners.rules.RuleFieldValidator.RULE_VALIDATOR;

import java.util.List;

import org.junit.After;
import org.junit.Before;
import org.junit.Ignore;
import org.junit.Rule;
import org.junit.Test;
import org.junit.Test.None;
import org.junit.internal.runners.model.ReflectiveCallable;
import org.junit.internal.runners.statements.ExpectException;
import org.junit.internal.runners.statements.Fail;
import org.junit.internal.runners.statements.FailOnTimeout;
import org.junit.internal.runners.statements.InvokeMethod;
import org.junit.internal.runners.statements.RunAfters;
import org.junit.internal.runners.statements.RunBefores;
import org.junit.rules.MethodRule;
import org.junit.rules.RunRules;
import org.junit.rules.TestRule;
import org.junit.runner.Description;
import org.junit.runner.notification.RunNotifier;
import org.junit.runners.model.FrameworkMethod;
import org.junit.runners.model.InitializationError;
import org.junit.runners.model.MultipleFailureException;
import org.junit.runners.model.Statement;

/**
* Implements the JUnit 4 standard test case class model, as defined by the
* annotations in the org.junit package. Many users will never notice this
* class: it is now the default test class runner, but it should have exactly
* the same behavior as the old test class runner ({@code JUnit4ClassRunner}).
*
* BlockJUnit4ClassRunner has advantages for writers of custom JUnit runners
* that are slight changes to the default behavior, however:
*
* <ul>
* <li>It has a much simpler implementation based on {@link Statement}s,
* allowing new operations to be inserted into the appropriate point in the
* execution flow.
*
* <li>It is published, and extension and reuse are encouraged, whereas {@code
* JUnit4ClassRunner} was in an internal package, and is now deprecated.
* </ul>
*/
public class BlockJUnit4ClassRunner extends ParentRunner<FrameworkMethod> {
  /**
   * Creates a BlockJUnit4ClassRunner to run {@code klass}
   *
   * @throws InitializationError
   *             if the test class is malformed.
   */
  public BlockJUnit4ClassRunner(Class<?> klass) throws InitializationError {
    super(klass);
  }

  //
  // Implementation of ParentRunner
  //

  @Override
  protected void runChild(final FrameworkMethod method, RunNotifier notifier) {
    Description description= describeChild(method);
    if (method.getAnnotation(Ignore.class) != null) {
      notifier.fireTestIgnored(description);
    } else {
      runLeaf(methodBlock(method), description, notifier);
    }
  }

  @Override
  protected Description describeChild(FrameworkMethod method) {
    return Description.createTestDescription(getTestClass().getJavaClass(),
        testName(method), method.getAnnotations());
  }

  @Override
  protected List<FrameworkMethod> getChildren() {
    return computeTestMethods();
  }

  //
  // Override in subclasses
  //

  /**
   * Returns the methods that run tests. Default implementation returns all
   * methods annotated with {@code @Test} on this class and superclasses that
   * are not overridden.
   */
  protected List<FrameworkMethod> computeTestMethods() {
    return getTestClass().getAnnotatedMethods(Test.class);
  }

  @Override
  protected void collectInitializationErrors(List<Throwable> errors) {
    super.collectInitializationErrors(errors);

    validateConstructor(errors);
    validateInstanceMethods(errors);
    validateFields(errors);
  }

  /**
   * Adds to {@code errors} if the test class has more than one constructor,
   * or if the constructor takes parameters. Override if a subclass requires
   * different validation rules.
   */
  protected void validateConstructor(List<Throwable> errors) {
    validateOnlyOneConstructor(errors);
    validateZeroArgConstructor(errors);
  }

  /**
   * Adds to {@code errors} if the test class has more than one constructor
   * (do not override)
   */
  protected void validateOnlyOneConstructor(List<Throwable> errors) {
    if (!hasOneConstructor()) {
      String gripe= "Test class should have exactly one public constructor";
      errors.add(new Exception(gripe));
    }
  }

  /**
   * Adds to {@code errors} if the test class's single constructor takes
   * parameters (do not override)
   */
  protected void validateZeroArgConstructor(List<Throwable> errors) {
    if (hasOneConstructor()
        && !(getTestClass().getOnlyConstructor().getParameterTypes().length == 0)) {
      String gripe= "Test class should have exactly one public zero-argument constructor";
      errors.add(new Exception(gripe));
    }
  }

  private boolean hasOneConstructor() {
    return getTestClass().getJavaClass().getConstructors().length == 1;
  }

  /**
   * Adds to {@code errors} for each method annotated with {@code @Test},
   * {@code @Before}, or {@code @After} that is not a public, void instance
   * method with no arguments.
   *
   * @deprecated unused API, will go away in future version
   */
  @Deprecated
  protected void validateInstanceMethods(List<Throwable> errors) {
    validatePublicVoidNoArgMethods(After.class, false, errors);
    validatePublicVoidNoArgMethods(Before.class, false, errors);
    validateTestMethods(errors);

    if (computeTestMethods().size() == 0)
      errors.add(new Exception("No runnable methods"));
  }

  private void validateFields(List<Throwable> errors) {
    RULE_VALIDATOR.validate(getTestClass(), errors);
  }

  /**
   * Adds to {@code errors} for each method annotated with {@code @Test}that
   * is not a public, void instance method with no arguments.
   */
  protected void validateTestMethods(List<Throwable> errors) {
    validatePublicVoidNoArgMethods(Test.class, false, errors);
  }

  /**
   * Returns a new fixture for running a test. Default implementation executes
   * the test class's no-argument constructor (validation should have ensured
   * one exists).
   */
  protected Object createTest() throws Exception {
    return getTestClass().getOnlyConstructor().newInstance();
  }

  /**
   * Returns the name that describes {@code method} for {@link Description}s.
   * Default implementation is the method's name
   */
  protected String testName(FrameworkMethod method) {
    return method.getName();
  }

  /**
   * Returns a Statement that, when executed, either returns normally if
   * {@code method} passes, or throws an exception if {@code method} fails.
   *
   * Here is an outline of the default implementation:
   *
   * <ul>
   * <li>Invoke {@code method} on the result of {@code createTest()}, and
   * throw any exceptions thrown by either operation.
   * <li>HOWEVER, if {@code method}'s {@code @Test} annotation has the {@code
   * expecting} attribute, return normally only if the previous step threw an
   * exception of the correct type, and throw an exception otherwise.
   * <li>HOWEVER, if {@code method}'s {@code @Test} annotation has the {@code
   * timeout} attribute, throw an exception if the previous step takes more
   * than the specified number of milliseconds.
   * <li>ALWAYS run all non-overridden {@code @Before} methods on this class
   * and superclasses before any of the previous steps; if any throws an
   * Exception, stop execution and pass the exception on.
   * <li>ALWAYS run all non-overridden {@code @After} methods on this class
   * and superclasses after any of the previous steps; all After methods are
   * always executed: exceptions thrown by previous steps are combined, if
   * necessary, with exceptions from After methods into a
   * {@link MultipleFailureException}.
   * <li>ALWAYS allow {@code @Rule} fields to modify the execution of the
   * above steps. A {@code Rule} may prevent all execution of the above steps,
   * or add additional behavior before and after, or modify thrown exceptions.
   * For more information, see {@link TestRule}
   * </ul>
   *
   * This can be overridden in subclasses, either by overriding this method,
   * or the implementations creating each sub-statement.
   */
  protected Statement methodBlock(FrameworkMethod method) {
    Object test;
    try {
      test= new ReflectiveCallable() {
        @Override
        protected Object runReflectiveCall() throws Throwable {
          return createTest();
        }
      }.run();
    } catch (Throwable e) {
      return new Fail(e);
    }

    Statement statement= methodInvoker(method, test);
    statement= possiblyExpectingExceptions(method, test, statement);
    statement= withPotentialTimeout(method, test, statement);
    statement= withBefores(method, test, statement);
    statement= withAfters(method, test, statement);
    statement= withRules(method, test, statement);
    return statement;
  }

  //
  // Statement builders
  //

  /**
   * Returns a {@link Statement} that invokes {@code method} on {@code test}
   */
  protected Statement methodInvoker(FrameworkMethod method, Object test) {
    return new InvokeMethod(method, test);
  }

  /**
   * Returns a {@link Statement}: if {@code method}'s {@code @Test} annotation
   * has the {@code expecting} attribute, return normally only if {@code next}
   * throws an exception of the correct type, and throw an exception
   * otherwise.
   *
   * @deprecated Will be private soon: use Rules instead
   */
  @Deprecated
  protected Statement possiblyExpectingExceptions(FrameworkMethod method,
      Object test, Statement next) {
    Test annotation= method.getAnnotation(Test.class);
    return expectsException(annotation) ? new ExpectException(next,
        getExpectedException(annotation)) : next;
  }

  /**
   * Returns a {@link Statement}: if {@code method}'s {@code @Test} annotation
   * has the {@code timeout} attribute, throw an exception if {@code next}
   * takes more than the specified number of milliseconds.
   *
   * @deprecated Will be private soon: use Rules instead
   */
  @Deprecated
  protected Statement withPotentialTimeout(FrameworkMethod method,
      Object test, Statement next) {
    long timeout= getTimeout(method.getAnnotation(Test.class));
    return timeout > 0 ? new FailOnTimeout(next, timeout) : next;
  }

  /**
   * Returns a {@link Statement}: run all non-overridden {@code @Before}
   * methods on this class and superclasses before running {@code next}; if
   * any throws an Exception, stop execution and pass the exception on.
   *
   * @deprecated Will be private soon: use Rules instead
   */
  @Deprecated
  protected Statement withBefores(FrameworkMethod method, Object target,
      Statement statement) {
    List<FrameworkMethod> befores= getTestClass().getAnnotatedMethods(
        Before.class);
    return befores.isEmpty() ? statement : new RunBefores(statement,
        befores, target);
  }

  /**
   * Returns a {@link Statement}: run all non-overridden {@code @After}
   * methods on this class and superclasses before running {@code next}; all
   * After methods are always executed: exceptions thrown by previous steps
   * are combined, if necessary, with exceptions from After methods into a
   * {@link MultipleFailureException}.
   *
   * @deprecated Will be private soon: use Rules instead
   */
  @Deprecated
  protected Statement withAfters(FrameworkMethod method, Object target,
      Statement statement) {
    List<FrameworkMethod> afters= getTestClass().getAnnotatedMethods(
        After.class);
    return afters.isEmpty() ? statement : new RunAfters(statement, afters,
        target);
  }

  private Statement withRules(FrameworkMethod method, Object target,
      Statement statement) {
    Statement result= statement;
    result= withMethodRules(method, target, result);
    result= withTestRules(method, target, result);
    return result;
  }

  @SuppressWarnings("deprecation")
  private Statement withMethodRules(FrameworkMethod method, Object target,
      Statement result) {
    List<TestRule> testRules= getTestRules(target);
    for (org.junit.rules.MethodRule each : getMethodRules(target))
      if (! testRules.contains(each))
        result= each.apply(result, method, target);
    return result;
  }

  @SuppressWarnings("deprecation")
  private List<org.junit.rules.MethodRule> getMethodRules(Object target) {
    return rules(target);
  }

  /**
   * @param target
   *            the test case instance
   * @return a list of MethodRules that should be applied when executing this
   *         test
   * @deprecated {@link org.junit.rules.MethodRule} is a deprecated interface. Port to
   *             {@link TestRule} and
   *             {@link BlockJUnit4ClassRunner#getTestRules(Object)}
   */
  @Deprecated
  protected List<org.junit.rules.MethodRule> rules(Object target) {
    return getTestClass().getAnnotatedFieldValues(target, Rule.class,
        org.junit.rules.MethodRule.class);
  }

  /**
   * Returns a {@link Statement}: apply all non-static {@link Value} fields
   * annotated with {@link Rule}.
   *
   * @param statement The base statement
   * @return a RunRules statement if any class-level {@link Rule}s are
   *         found, or the base statement
   */
  private Statement withTestRules(FrameworkMethod method, Object target,
      Statement statement) {
    List<TestRule> testRules= getTestRules(target);
    return testRules.isEmpty() ? statement :
      new RunRules(statement, testRules, describeChild(method));
  }

  /**
   * @param target
   *            the test case instance
   * @return a list of TestRules that should be applied when executing this
   *         test
   */
  protected List<TestRule> getTestRules(Object target) {
    return getTestClass().getAnnotatedFieldValues(target,
        Rule.class, TestRule.class);
  }

  private Class<? extends Throwable> getExpectedException(Test annotation) {
    if (annotation == null || annotation.expected() == None.class)
      return null;
    else
      return annotation.expected();
  }

  private boolean expectsException(Test annotation) {
    return getExpectedException(annotation) != null;
  }

  private long getTimeout(Test annotation) {
    if (annotation == null)
      return 0;
    return annotation.timeout();
  }
}
TOP

Related Classes of org.junit.runners.BlockJUnit4ClassRunner

TOP
Copyright © 2018 www.massapi.com. All rights reserved.
All source code are property of their respective owners. Java is a trademark of Sun Microsystems, Inc and owned by ORACLE Inc. Contact coftware#gmail.com.