// Protocol Buffers - Google's data interchange format
// Copyright 2008 Google Inc.  All rights reserved.
// http://code.google.com/p/protobuf/
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
//     * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
//     * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
//     * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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package com.google.protobuf;

import junit.framework.TestCase;

/**
 * Tests for {@link LazyStringArrayList}.
 *
 * @author jonp@google.com (Jon Perlow)
 */
public class LazyStringArrayListTest extends TestCase {

  private static String STRING_A = "A";
  private static String STRING_B = "B";
  private static String STRING_C = "C";

  private static ByteString BYTE_STRING_A = ByteString.copyFromUtf8("A");
  private static ByteString BYTE_STRING_B = ByteString.copyFromUtf8("B");
  private static ByteString BYTE_STRING_C = ByteString.copyFromUtf8("C");

  public void testJustStrings() {
    LazyStringArrayList list = new LazyStringArrayList();
    list.add(STRING_A);
    list.add(STRING_B);
    list.add(STRING_C);

    assertEquals(3, list.size());
    assertSame(STRING_A, list.get(0));
    assertSame(STRING_B, list.get(1));
    assertSame(STRING_C, list.get(2));

    list.set(1, STRING_C);
    assertSame(STRING_C, list.get(1));

    list.remove(1);
    assertSame(STRING_A, list.get(0));
    assertSame(STRING_C, list.get(1));
  }

  public void testJustByteString() {
    LazyStringArrayList list = new LazyStringArrayList();
    list.add(BYTE_STRING_A);
    list.add(BYTE_STRING_B);
    list.add(BYTE_STRING_C);

    assertEquals(3, list.size());
    assertSame(BYTE_STRING_A, list.getByteString(0));
    assertSame(BYTE_STRING_B, list.getByteString(1));
    assertSame(BYTE_STRING_C, list.getByteString(2));

    list.remove(1);
    assertSame(BYTE_STRING_A, list.getByteString(0));
    assertSame(BYTE_STRING_C, list.getByteString(1));
  }

  public void testConversionBackAndForth() {
    LazyStringArrayList list = new LazyStringArrayList();
    list.add(STRING_A);
    list.add(BYTE_STRING_B);
    list.add(BYTE_STRING_C);

    // String a should be the same because it was originally a string
    assertSame(STRING_A, list.get(0));

    // String b and c should be different because the string has to be computed
    // from the ByteString
    String bPrime = list.get(1);
    assertNotSame(STRING_B, bPrime);
    assertEquals(STRING_B, bPrime);
    String cPrime = list.get(2);
    assertNotSame(STRING_C, cPrime);
    assertEquals(STRING_C, cPrime);

    // String c and c should stay the same once cached.
    assertSame(bPrime, list.get(1));
    assertSame(cPrime, list.get(2));

    // ByteString needs to be computed from string for both a and b
    ByteString aPrimeByteString = list.getByteString(0);
    assertEquals(BYTE_STRING_A, aPrimeByteString);
    ByteString bPrimeByteString = list.getByteString(1);
    assertNotSame(BYTE_STRING_B, bPrimeByteString);
    assertEquals(BYTE_STRING_B, list.getByteString(1));

    // Once cached, ByteString should stay cached.
    assertSame(aPrimeByteString, list.getByteString(0));
    assertSame(bPrimeByteString, list.getByteString(1));
  }
}
