package org.junit.runner.notification;

import java.io.PrintWriter;

import java.io.StringWriter;

import org.junit.runner.Description;

/**

 * A <code>Failure</code> holds a description of the failed test and the 

 * exception that was thrown while running it. In most cases the {@link org.junit.runner.Description}

 * will be of a single test. However, if problems are encountered while constructing the

 * test (for example, if a {@link org.junit.BeforeClass} method is not static), it may describe

 * something other than a single test.

 */

public class Failure {

	private final Description fDescription;

	private Throwable fThrownException;

	/**

	 * Constructs a <code>Failure</code> with the given description and exception.

	 * @param description a {@link org.junit.runner.Description} of the test that failed

	 * @param thrownException the exception that was thrown while running the test

	 */

	public Failure(Description description, Throwable thrownException) {

		fThrownException = thrownException;

		fDescription= description;

	}

	/**

	 * @return a user-understandable label for the test

	 */

	public String getTestHeader() {

		return fDescription.getDisplayName();

	}

	/**

	 * @return the raw description of the context of the failure.

	 */

	public Description getDescription() {

		return fDescription;

	}

	/**

	 * @return the exception thrown

	 */

	public Throwable getException() {

	    return fThrownException;

	}

	@Override

	public String toString() {

	    StringBuffer buffer= new StringBuffer();

	    buffer.append(getTestHeader() + ": "+fThrownException.getMessage());

	    return buffer.toString();

	}

	/**

	 * Convenience method

	 * @return the printed form of the exception

	 */

	public String getTrace() {

		StringWriter stringWriter= new StringWriter();

		PrintWriter writer= new PrintWriter(stringWriter);

		getException().printStackTrace(writer);

		StringBuffer buffer= stringWriter.getBuffer();

		return buffer.toString();

	}

	/**

	 * Convenience method

	 * @return the message of the thrown exception

	 */

	public String getMessage() {

		return getException().getMessage();

	}

}