LongestCommonSubsequenceCalculator_Tests.cs

using System.Collections.Generic;
using System.Linq;
using NUnit.Framework;

namespace Antiplagiarism
{
    [TestFixture]
    public class LongestCommonSubsequenceCalculator_Tests
    {
        private const string Ax10 = "a a a a a a a a a a";
        private const string Bx10 = "b b b b b b b b b b";

        [TestCase("a", "a", 1)]
        [TestCase("a", "b", 0)]
        [TestCase("a", "", 0)]
        [TestCase("", "b", 0)]
        [TestCase("a", "a a", 1)]
        [TestCase("a a", "a b", 1)]
        [TestCase("a b", "a a b b", 2)]
        [TestCase("a a b b", "a b", 2)]
        public void TestSimple(string first, string second, int expectedSubsequenceLength)
            => DoTest(first, second, expectedSubsequenceLength);

        [TestCase("к о т", "к л о н", 2)]
        [TestCase("y a b x", "a b c d", 2)]
        [TestCase("с т у д е н т", "с о л д а т", 3)]
        public void TestWords(string first, string second, int expectedSubsequenceLength)
            => DoTest(first, second, expectedSubsequenceLength);

        [TestCase(Ax10, Bx10, 0)]
        [TestCase(Ax10, "a", 1)]
        [TestCase(Ax10, "a a", 2)]
        [TestCase(Ax10 + " " + Bx10, "a a a a a b b b b b", 10)]
        [TestCase("a b b b a b a", "a a b b b a b b", 6)]
        [TestCase("a b b b a b a", "a a a a a a a", 3)]
        [TestCase("a b b b a b a", "b b b b b b", 4)]
        [TestCase("a b b b a b a", "a b b a b b a", 6)]
        [TestCase("b b b b a a b b b a", "a a a b b b a a a b", 6)]
        [TestCase("b a a b a b b a b b a b b a b", "b b b a b a b b b b a a a b b", 11)]
        [TestCase(
            "b b a b b a a b b b b a a a a a a b a b",
            "a a b a b b b b a b a a b a a b b a a a", 14)]
        [TestCase(
            "a b a a b b b b b b b b b b a a a a b b b a b b a",
            "a b b b b a b a a b b a a a b a a b a a b b a a a", 17)]
        [TestCase(
            "b a a b b a a b a b b b a a b a a a a a b a b b b a b b a a",
            "a a b b a a b a a a b b b a a a b a a b a b a b b b a b a a", 26)]
        [TestCase(
            "a b b b a b a a b a b b a b b a a b a b b b a b a b a b b a b a b b a b a",
            "a a a b b b b b b b a a a b a b a a b a a b b a b b a", 24)]
        [TestCase(
            "b a b a a b b b a b b a b b b b a a a b a b b b b a b b b a a a b a b b b b a a b a b a b b a b b b",
            "b a b a b b b b b b b b b a b a a a b b a b b b b a b b b a a a b b a a b a b b b a a b b b a a a a b b",
            43)]
        public void TestBig(string first, string second, int expectedSubsequenceLength)
            => DoTest(first, second, expectedSubsequenceLength);

        [TestCase("aa bb", "aa ab", 1)]
        [TestCase("abb cbaa ca", "ccb ca", 1)]
        [TestCase("aa bbcc aa bba", "aa cc aa cc bba", 3)]
        [TestCase("ab cr e f", "abf jjc a re", 0)]
        [TestCase("abc bca cab bba", "abc xx bca cab ba ca cab bba", 4)]
        [TestCase("hrc ** &) + 129x", "rc& 123 987 + - ** + << 129x", 3)]
        public void TestMultiLetter(string first, string second, int expectedSubsequenceLength)
            => DoTest(first, second, expectedSubsequenceLength);

        private void DoTest(
            string first, string second,
            int expectedSubsequenceLength)
        {
            var firstSequence = first.Split(' ').ToList();
            var secondSequence = second.Split(' ').ToList();
            var actual = LongestCommonSubsequenceCalculator.Calculate(firstSequence, secondSequence);

            Assert.AreEqual(expectedSubsequenceLength, actual.Count);
            AssertSubsequence(actual, firstSequence);
            AssertSubsequence(actual, secondSequence);
            Assert.IsTrue(actual.All(firstSequence.Contains), // Contains будет сравнивать токены по ссылкам
                nameof(LongestCommonSubsequenceCalculator) + " должен возвращать токены первого документа");
        }

        private void AssertSubsequence(IList<string> subsequence, IList<string> sequence)
        {
            var i = 0;
            foreach (var token in sequence)
            {
                if (i == subsequence.Count) break;
                if (token == subsequence[i]) ++i;
            }

            if (i != subsequence.Count)
            {
                Assert.Fail(
                    $"Expected to be subsequence.\nSequence: <{string.Join(" ", sequence)}>, expected subsequence <{string.Join(" ", subsequence)}>");
            }
        }
    }
}