/*
    * Copyright (C) 2008 The Guava 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 com.google.common.testing;
  
  import junit.framework.TestCase;
  
  import java.util.logging.Level;
  import java.util.logging.LogRecord;
  import java.util.logging.Logger;
  
  /**
   * Unit test for {@link TestLogHandler}.
   *
   * @author kevinb
   */
  public class TestLogHandlerTest extends TestCase {
  
    private TestLogHandler handler;
    private TearDownStack stack = new TearDownStack();
  
    @Override protected void setUp() throws Exception {
      super.setUp();
  
      handler = new TestLogHandler();
  
      // You could also apply it higher up the Logger hierarchy than this
      ExampleClassUnderTest.logger.addHandler(handler);
  
      ExampleClassUnderTest.logger.setUseParentHandlers(false); // optional
  
      stack.addTearDown(new TearDown() {
        @Override
        public void tearDown() throws Exception {
          ExampleClassUnderTest.logger.setUseParentHandlers(true);
          ExampleClassUnderTest.logger.removeHandler(handler);
        }
      });
    }
  
    public void test() throws Exception {
      assertTrue(handler.getStoredLogRecords().isEmpty());
      ExampleClassUnderTest.foo();
      LogRecord record = handler.getStoredLogRecords().get(0);
      assertEquals(Level.INFO, record.getLevel());
      assertEquals("message", record.getMessage());
      assertSame(EXCEPTION, record.getThrown());
    }
  
    public void testConcurrentModification() throws Exception {
      // Tests for the absence of a bug where logging while iterating over the
      // stored log records causes a ConcurrentModificationException
      assertTrue(handler.getStoredLogRecords().isEmpty());
      ExampleClassUnderTest.foo();
      ExampleClassUnderTest.foo();
      for (LogRecord unused : handler.getStoredLogRecords()) {
        ExampleClassUnderTest.foo();
      }
    }
  
    @Override public final void runBare() throws Throwable {
      try {
        setUp();
        runTest();
      } finally {
        tearDown();
      }
    }
  
    @Override protected void tearDown() {
      stack.runTearDown();
    }
  
    static final Exception EXCEPTION = new Exception();
  
    static class ExampleClassUnderTest {
      static final Logger logger
          = Logger.getLogger(ExampleClassUnderTest.class.getName());
  
      static void foo() {
        logger.log(Level.INFO,  "message", EXCEPTION);
      }
    }
  }