/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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 javax.jdo.util;

import java.io.PrintStream;
import javax.jdo.Constants;
import junit.framework.TestCase;

/** */
public abstract class AbstractTest extends TestCase implements Constants {

  /** */
  protected static final PrintStream OUT = System.out;

  /** If true, print extra messages. */
  protected final boolean verbose;

  /** Construct and initialize from properties. */
  protected AbstractTest() {
    super(null);
    verbose = Boolean.getBoolean("verbose");
  }

  /** Determine if a class is loadable in the current environment. */
  protected static boolean isClassLoadable(String className) {
    try {
      Class.forName(className);
      return true;
    } catch (ClassNotFoundException ex) {
      return false;
    }
  }

  /** */
  protected void println(String s) {
    if (verbose) OUT.println(s);
  }

  /** New line. */
  public static final String NL = System.getProperty("line.separator");

  /** A buffer of of error messages. */
  protected static StringBuffer messages;

  /** Appends to error messages. */
  protected static synchronized void appendMessage(String message) {
    if (message != null) {
      if (messages == null) {
        messages = new StringBuffer();
      }
      messages.append(message);
      messages.append(NL);
    }
  }

  /**
   * Returns collected error messages, or <code>null</code> if there are none, and clears the
   * buffer.
   */
  protected static synchronized String retrieveMessages() {
    if (messages == null) {
      return null;
    }
    final String msg = messages.toString();
    messages = null;
    return msg;
  }

  /** Fail the test if there are any error messages. */
  protected void failOnError() {
    String errors = retrieveMessages();
    if (errors != null) {
      fail(errors);
    }
  }
}