core/src/main/java/com/google/common/truth/PrimitiveByteArraySubject.java

/*
 * Copyright (c) 2014 Google, Inc.
 *
 * 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.truth;

import com.google.common.primitives.Bytes;
import java.util.Arrays;
import java.util.List;
import javax.annotation.Nullable;

/**
 * A Subject to handle testing propositions for {@code byte[]}.
 *
 * @author Kurt Alfred Kluever
 */
public final class PrimitiveByteArraySubject
    extends AbstractArraySubject<PrimitiveByteArraySubject, byte[]> {
  PrimitiveByteArraySubject(FailureStrategy failureStrategy, @Nullable byte[] o) {
    super(failureStrategy, o);
  }

  @Override
  protected String underlyingType() {
    return "byte";
  }

  @Override
  protected List<Byte> listRepresentation() {
    return Bytes.asList(actual());
  }

  /**
   * A proposition that the actual array and {@code expected} are arrays of the same length and
   * type, containing elements such that each element in {@code expected} is equal to each element
   * in the actual array, and in the same position.
   */
  @Override
  public void isEqualTo(Object expected) {
    byte[] actual = actual();
    if (actual == expected) {
      return; // short-cut.
    }
    try {
      byte[] expectedArray = (byte[]) expected;
      if (!Arrays.equals(actual, expectedArray)) {
        failureStrategy.failComparing(
            "Not true that "
                + getDisplaySubject()
                + " is equal to <"
                + Arrays.toString(expectedArray)
                + ">;",
            base16(expectedArray),
            base16(getSubject()));
      }
    } catch (ClassCastException e) {
      failWithBadType(expected);
    }
  }

  // We could add a dep on com.google.common.io, but that seems overkill for base16 encoding
  private static String base16(byte[] bytes) {
    StringBuilder sb = new StringBuilder(2 * bytes.length);
    for (byte b : bytes) {
      sb.append(hexDigits[(b >> 4) & 0xf]).append(hexDigits[b & 0xf]);
    }
    return sb.toString();
  }

  private static final char[] hexDigits = "0123456789ABCDEF".toCharArray();

  /**
   * A proposition that the actual array and {@code expected} are not arrays of the same length and
   * type, containing elements such that each element in {@code expected} is equal to each element
   * in the actual array, and in the same position.
   */
  @Override
  public void isNotEqualTo(Object expected) {
    byte[] actual = actual();
    try {
      byte[] expectedArray = (byte[]) expected;
      if (actual == expected || Arrays.equals(actual, expectedArray)) {
        failWithRawMessage(
            "%s unexpectedly equal to %s.", actualAsString(), Arrays.toString(expectedArray));
      }
    } catch (ClassCastException ignored) {
      // If it's not byte[] then it's not equal and the test passes.
    }
  }

  public IterableSubject asList() {
    return internalCustomName() != null
        ? check().that(listRepresentation()).named(internalCustomName())
        : check().that(listRepresentation());
  }
}