Add filter evaluating unit tests

Introduce unit tests covering the actual evaluation of filters for
beatmaps. Partially covers most scenarios.

osu.Game.Tests/NonVisual/Filtering/FilterMatchingTest.cs

@@ -0,0 +1,136 @@
+// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
+// See the LICENCE file in the repository root for full licence text.
+
+using NUnit.Framework;
+using osu.Game.Beatmaps;
+using osu.Game.Rulesets;
+using osu.Game.Screens.Select;
+using osu.Game.Screens.Select.Carousel;
+
+namespace osu.Game.Tests.NonVisual.Filtering
+{
+    [TestFixture]
+    public class FilterMatchingTest
+    {
+        private readonly BeatmapInfo exampleBeatmapInfo = new BeatmapInfo
+        {
+            Ruleset = new RulesetInfo { ID = 5 },
+            StarDifficulty = 4.0d,
+            BaseDifficulty = new BeatmapDifficulty
+            {
+                ApproachRate = 5.0f,
+                DrainRate = 3.0f,
+                CircleSize = 2.0f,
+            },
+            Metadata = new BeatmapMetadata
+            {
+                Artist = "The Artist",
+                ArtistUnicode = "The Artist",
+                Title = "Title goes here",
+                TitleUnicode = "Title goes here",
+                AuthorString = "Author",
+                Source = "unit tests",
+                Tags = "look for tags too",
+            },
+            Version = "version as well",
+            Length = 2500,
+            BPM = 160,
+            BeatDivisor = 12,
+            Status = BeatmapSetOnlineStatus.Loved
+        };
+
+        [Test]
+        public void TestCriteriaMatchingNoRuleset()
+        {
+            var criteria = new FilterCriteria();
+            var carouselItem = new CarouselBeatmap(exampleBeatmapInfo);
+            carouselItem.Filter(criteria);
+            Assert.IsFalse(carouselItem.Filtered.Value);
+        }
+
+        [Test]
+        public void TestCriteriaMatchingSpecificRuleset()
+        {
+            var criteria = new FilterCriteria
+            {
+                Ruleset = new RulesetInfo { ID = 6 }
+            };
+            var carouselItem = new CarouselBeatmap(exampleBeatmapInfo);
+            carouselItem.Filter(criteria);
+            Assert.IsTrue(carouselItem.Filtered.Value);
+        }
+
+        [Test]
+        public void TestCriteriaMatchingConvertedBeatmaps()
+        {
+            var criteria = new FilterCriteria
+            {
+                Ruleset = new RulesetInfo { ID = 6 },
+                AllowConvertedBeatmaps = true
+            };
+            var carouselItem = new CarouselBeatmap(exampleBeatmapInfo);
+            carouselItem.Filter(criteria);
+            Assert.IsFalse(carouselItem.Filtered.Value);
+        }
+
+        [Test]
+        [TestCase(true)]
+        [TestCase(false)]
+        public void TestCriteriaMatchingRangeMin(bool inclusive)
+        {
+            var criteria = new FilterCriteria
+            {
+                Ruleset = new RulesetInfo { ID = 6 },
+                AllowConvertedBeatmaps = true,
+                ApproachRate = new FilterCriteria.OptionalRange<float>
+                {
+                    IsLowerInclusive = inclusive,
+                    Min = 5.0f
+                }
+            };
+            var carouselItem = new CarouselBeatmap(exampleBeatmapInfo);
+            carouselItem.Filter(criteria);
+            Assert.AreEqual(!inclusive, carouselItem.Filtered.Value);
+        }
+
+        [Test]
+        [TestCase(true)]
+        [TestCase(false)]
+        public void TestCriteriaMatchingRangeMax(bool inclusive)
+        {
+            var criteria = new FilterCriteria
+            {
+                Ruleset = new RulesetInfo { ID = 6 },
+                AllowConvertedBeatmaps = true,
+                BPM = new FilterCriteria.OptionalRange<double>
+                {
+                    IsUpperInclusive = inclusive,
+                    Max = 160d
+                }
+            };
+            var carouselItem = new CarouselBeatmap(exampleBeatmapInfo);
+            carouselItem.Filter(criteria);
+            Assert.AreEqual(!inclusive, carouselItem.Filtered.Value);
+        }
+
+        [Test]
+        [TestCase("artist", false)]
+        [TestCase("artist title author", false)]
+        [TestCase("an artist", true)]
+        [TestCase("tags too", false)]
+        [TestCase("version", false)]
+        [TestCase("an auteur", true)]
+        public void TestCriteriaMatchingTerms(string terms, bool filtered)
+        {
+            var criteria = new FilterCriteria
+            {
+                Ruleset = new RulesetInfo { ID = 6 },
+                AllowConvertedBeatmaps = true,
+                SearchText = terms
+            };
+            var carouselItem = new CarouselBeatmap(exampleBeatmapInfo);
+            carouselItem.Filter(criteria);
+            Assert.AreEqual(filtered, carouselItem.Filtered.Value);
+        }
+    }
+}