Class InputStreams

src/main/java/org/assertj/core/internal/InputStreams.java:32–79

Reusable assertions for InputStream s. @author Matthieu Baechler

 * @author Matthieu Baechler
 */
public class InputStreams {

  private static final InputStreams INSTANCE = new InputStreams();

  /**
   * Returns the singleton instance of this class.
   * @return the singleton instance of this class.
   */
  public static InputStreams instance() {
    return INSTANCE;
  }

  @VisibleForTesting
  Diff diff = new Diff();
  @VisibleForTesting
  Failures failures = Failures.instance();

  @VisibleForTesting
  InputStreams() {}

  /**
   * Asserts that the given InputStreams have equal content.
   * 
   * @param info contains information about the assertion.
   * @param actual the "actual" InputStream.
   * @param expected the "expected" InputStream.
   * @throws NullPointerException if {@code expected} is {@code null}.
   * @throws AssertionError if {@code actual} is {@code null}.
   * @throws AssertionError if the given InputStreams do not have equal content.
   * @throws InputStreamsException if an I/O error occurs.
   */
  public void assertEqualContent(AssertionInfo info, InputStream actual, InputStream expected) {
    if (expected == null) throw new NullPointerException("The InputStream to compare to should not be null");
    assertNotNull(info, actual);
    try {
      List<String> diffs = diff.diff(actual, expected);
      if (diffs.isEmpty()) return;
      throw failures.failure(info, shouldHaveEqualContent(actual, expected, diffs));
    } catch (IOException e) {
      String msg = format("Unable to compare contents of InputStreams:\n  <%s>\nand:\n  <%s>", actual, expected);
      throw new InputStreamsException(msg, e);
    }
  }

  private static void assertNotNull(AssertionInfo info, InputStream stream) {
    Objects.instance().assertNotNull(info, stream);
  }
}