001 /*
002 * Created on Jan 26, 2011
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
005 * the License. You may obtain a copy of the License at
006 *
007 * http://www.apache.org/licenses/LICENSE-2.0
008 *
009 * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
010 * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
011 * specific language governing permissions and limitations under the License.
012 *
013 * Copyright @2011 the original author or authors.
014 */
015 package org.fest.assertions.internal;
016
017 import static java.lang.String.format;
018
019 import static org.fest.assertions.error.ShouldHaveEqualContent.shouldHaveEqualContent;
020
021 import java.io.IOException;
022 import java.io.InputStream;
023 import java.util.List;
024
025 import org.fest.assertions.core.AssertionInfo;
026 import org.fest.util.VisibleForTesting;
027
028 /**
029 * Reusable assertions for <code>{@link InputStream}</code>s.
030 *
031 * @author Matthieu Baechler
032 */
033 public class InputStreams {
034
035 private static final InputStreams INSTANCE = new InputStreams();
036
037 /**
038 * Returns the singleton instance of this class.
039 * @return the singleton instance of this class.
040 */
041 public static InputStreams instance() {
042 return INSTANCE;
043 }
044
045 @VisibleForTesting
046 Diff diff = new Diff();
047 @VisibleForTesting
048 Failures failures = Failures.instance();
049
050 @VisibleForTesting
051 InputStreams() {}
052
053 /**
054 * Asserts that the given InputStreams have equal content.
055 *
056 * @param info contains information about the assertion.
057 * @param actual the "actual" InputStream.
058 * @param expected the "expected" InputStream.
059 * @throws NullPointerException if {@code expected} is {@code null}.
060 * @throws AssertionError if {@code actual} is {@code null}.
061 * @throws AssertionError if the given InputStreams do not have equal content.
062 * @throws InputStreamsException if an I/O error occurs.
063 */
064 public void assertEqualContent(AssertionInfo info, InputStream actual, InputStream expected) {
065 if (expected == null) throw new NullPointerException("The InputStream to compare to should not be null");
066 assertNotNull(info, actual);
067 try {
068 List<String> diffs = diff.diff(actual, expected);
069 if (diffs.isEmpty()) return;
070 throw failures.failure(info, shouldHaveEqualContent(actual, expected, diffs));
071 } catch (IOException e) {
072 String msg = format("Unable to compare contents of InputStreams :<%s> and:<%s>", actual, expected);
073 throw new InputStreamsException(msg, e);
074 }
075 }
076
077 private static void assertNotNull(AssertionInfo info, InputStream stream) {
078 Objects.instance().assertNotNull(info, stream);
079 }
080 }