Add too short sliders check and tests

osu.Game.Rulesets.Osu.Tests/Editor/Checks/CheckTooShortSlidersTest.cs

@@ -0,0 +1,145 @@
+// 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 System.Collections.Generic;
+using System.Linq;
+using NUnit.Framework;
+using osu.Game.Beatmaps;
+using osu.Game.Beatmaps.ControlPoints;
+using osu.Game.Rulesets.Edit;
+using osu.Game.Rulesets.Objects;
+using osu.Game.Rulesets.Osu.Edit.Checks;
+using osu.Game.Rulesets.Osu.Objects;
+using osu.Game.Tests.Beatmaps;
+using osuTK;
+
+namespace osu.Game.Rulesets.Osu.Tests.Editor.Checks
+{
+    [TestFixture]
+    public class CheckTooShortSlidersTest
+    {
+        private CheckTooShortSliders check;
+
+        [SetUp]
+        public void Setup()
+        {
+            check = new CheckTooShortSliders();
+        }
+
+        [Test]
+        public void TestLongSlider()
+        {
+            Slider slider = new Slider
+            {
+                StartTime = 0,
+                RepeatCount = 0,
+                Path = new SliderPath(new[]
+                {
+                    new PathControlPoint(new Vector2(0, 0)),
+                    new PathControlPoint(new Vector2(100, 0))
+                })
+            };
+
+            slider.ApplyDefaults(new ControlPointInfo(), new BeatmapDifficulty());
+
+            assertOk(new List<HitObject> { slider });
+        }
+
+        [Test]
+        public void TestShortSlider()
+        {
+            Slider slider = new Slider
+            {
+                StartTime = 0,
+                RepeatCount = 0,
+                Path = new SliderPath(new[]
+                {
+                    new PathControlPoint(new Vector2(0, 0)),
+                    new PathControlPoint(new Vector2(25, 0))
+                })
+            };
+
+            slider.ApplyDefaults(new ControlPointInfo(), new BeatmapDifficulty());
+
+            assertOk(new List<HitObject> { slider });
+        }
+
+        [Test]
+        public void TestTooShortSliderExpert()
+        {
+            Slider slider = new Slider
+            {
+                StartTime = 0,
+                RepeatCount = 0,
+                Path = new SliderPath(new[]
+                {
+                    new PathControlPoint(new Vector2(0, 0)),
+                    new PathControlPoint(new Vector2(10, 0))
+                })
+            };
+
+            slider.ApplyDefaults(new ControlPointInfo(), new BeatmapDifficulty());
+
+            assertOk(new List<HitObject> { slider }, DifficultyRating.Expert);
+        }
+
+        [Test]
+        public void TestTooShortSlider()
+        {
+            Slider slider = new Slider
+            {
+                StartTime = 0,
+                RepeatCount = 0,
+                Path = new SliderPath(new[]
+                {
+                    new PathControlPoint(new Vector2(0, 0)),
+                    new PathControlPoint(new Vector2(10, 0))
+                })
+            };
+
+            slider.ApplyDefaults(new ControlPointInfo(), new BeatmapDifficulty());
+
+            assertTooShort(new List<HitObject> { slider });
+        }
+
+        [Test]
+        public void TestTooShortSliderWithRepeats()
+        {
+            // Would be ok if we looked at the duration, but not if we look at the span duration.
+            Slider slider = new Slider
+            {
+                StartTime = 0,
+                RepeatCount = 2,
+                Path = new SliderPath(new[]
+                {
+                    new PathControlPoint(new Vector2(0, 0)),
+                    new PathControlPoint(new Vector2(10, 0))
+                })
+            };
+
+            slider.ApplyDefaults(new ControlPointInfo(), new BeatmapDifficulty());
+
+            assertTooShort(new List<HitObject> { slider });
+        }
+
+        private void assertOk(List<HitObject> hitObjects, DifficultyRating difficultyRating = DifficultyRating.Easy)
+        {
+            Assert.That(check.Run(getContext(hitObjects, difficultyRating)), Is.Empty);
+        }
+
+        private void assertTooShort(List<HitObject> hitObjects, DifficultyRating difficultyRating = DifficultyRating.Easy)
+        {
+            var issues = check.Run(getContext(hitObjects, difficultyRating)).ToList();
+
+            Assert.That(issues, Has.Count.EqualTo(1));
+            Assert.That(issues.First().Template is CheckTooShortSliders.IssueTemplateTooShort);
+        }
+
+        private BeatmapVerifierContext getContext(List<HitObject> hitObjects, DifficultyRating difficultyRating)
+        {
+            var beatmap = new Beatmap<HitObject> { HitObjects = hitObjects };
+
+            return new BeatmapVerifierContext(beatmap, new TestWorkingBeatmap(beatmap), difficultyRating);
+        }
+    }
+}

osu.Game.Rulesets.Osu/Edit/Checks/CheckTooShortSliders.cs

@@ -0,0 +1,48 @@
+// 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 System.Collections.Generic;
+using osu.Game.Beatmaps;
+using osu.Game.Rulesets.Edit;
+using osu.Game.Rulesets.Edit.Checks.Components;
+using osu.Game.Rulesets.Osu.Objects;
+
+namespace osu.Game.Rulesets.Osu.Edit.Checks
+{
+    public class CheckTooShortSliders : ICheck
+    {
+        /// <summary>
+        /// The shortest acceptable duration between the head and tail of the slider (so ignoring repeats).
+        /// </summary>
+        private const double span_duration_threshold = 125; // 240 BPM 1/2
+
+        public CheckMetadata Metadata { get; } = new CheckMetadata(CheckCategory.Spread, "Too short sliders");
+
+        public IEnumerable<IssueTemplate> PossibleTemplates => new IssueTemplate[]
+        {
+            new IssueTemplateTooShort(this)
+        };
+
+        public IEnumerable<Issue> Run(BeatmapVerifierContext context)
+        {
+            if (context.InterpretedDifficulty > DifficultyRating.Easy)
+                yield break;
+
+            foreach (var hitObject in context.Beatmap.HitObjects)
+            {
+                if (hitObject is Slider slider && slider.SpanDuration < span_duration_threshold)
+                    yield return new IssueTemplateTooShort(this).Create(slider);
+            }
+        }
+
+        public class IssueTemplateTooShort : IssueTemplate
+        {
+            public IssueTemplateTooShort(ICheck check)
+                : base(check, IssueType.Problem, "This slider is too short ({0:0} ms), expected at least {1:0} ms.")
+            {
+            }
+
+            public Issue Create(Slider slider) => new Issue(slider, this, slider.SpanDuration, span_duration_threshold);
+        }
+    }
+}