Add example checks

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

@@ -0,0 +1,86 @@
+// 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 osu.Game.Beatmaps;
+using osu.Game.Rulesets.Objects;
+using osu.Game.Rulesets.Osu.Objects;
+using osu.Game.Screens.Edit.Verify;
+using osu.Game.Screens.Edit.Verify.Components;
+
+namespace osu.Game.Rulesets.Osu.Edit.Checks
+{
+    public class CheckConsecutiveCircles : BeatmapCheck
+    {
+        private const double consecutive_threshold = 3;
+        private const double delta_time_min_expected = 300;
+        private const double delta_time_min_threshold = 100;
+
+        public override CheckMetadata Metadata() => new CheckMetadata
+        (
+            category: CheckMetadata.CheckCategory.Spread,
+            description: "Too many or fast consecutive circles."
+        );
+
+        private IssueTemplate templateManyInARow = new IssueTemplate
+        (
+            type: IssueTemplate.IssueType.Problem,
+            unformattedMessage: "There are {0} circles in a row here, expected at most {1}."
+        );
+
+        private IssueTemplate templateTooFast = new IssueTemplate
+        (
+            type: IssueTemplate.IssueType.Warning,
+            unformattedMessage: "These circles are too fast ({0:0} ms), expected at least {1:0} ms."
+        );
+
+        private IssueTemplate templateAlmostTooFast = new IssueTemplate
+        (
+            type: IssueTemplate.IssueType.Negligible,
+            unformattedMessage: "These circles are almost too fast ({0:0} ms), expected at least {1:0} ms."
+        );
+
+        public override IEnumerable<IssueTemplate> Templates() => new[]
+        {
+            templateManyInARow,
+            templateTooFast,
+            templateAlmostTooFast
+        };
+
+        public override IEnumerable<Issue> Run(IBeatmap beatmap)
+        {
+            List<HitCircle> prevCircles = new List<HitCircle>();
+
+            foreach (HitObject hitobject in beatmap.HitObjects)
+            {
+                if (!(hitobject is HitCircle circle) || hitobject == beatmap.HitObjects.Last())
+                {
+                    if (prevCircles.Count > consecutive_threshold)
+                    {
+                        yield return new Issue(
+                            prevCircles,
+                            templateManyInARow,
+                            prevCircles.Count, consecutive_threshold
+                        );
+                    }
+
+                    prevCircles.Clear();
+                    continue;
+                }
+
+                double? prevDeltaTime = circle.StartTime - prevCircles.LastOrDefault()?.StartTime;
+                prevCircles.Add(circle);
+
+                if (prevDeltaTime == null || prevDeltaTime >= delta_time_min_expected)
+                    continue;
+
+                yield return new Issue(
+                    prevCircles.TakeLast(2),
+                    prevDeltaTime < delta_time_min_threshold ? templateTooFast : templateAlmostTooFast,
+                    prevDeltaTime, delta_time_min_expected
+                );
+            }
+        }
+    }
+}

osu.Game/Checks/CheckMetadataVowels.cs

@@ -0,0 +1,65 @@
+// 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 osu.Game.Beatmaps;
+using osu.Game.Screens.Edit.Verify;
+using osu.Game.Screens.Edit.Verify.Components;
+
+namespace osu.Game.Checks
+{
+    public class CheckMetadataVowels : BeatmapCheck
+    {
+        private static readonly char[] vowels = { 'a', 'e', 'i', 'o', 'u' };
+
+        public override CheckMetadata Metadata() => new CheckMetadata
+        (
+            category: CheckMetadata.CheckCategory.Metadata,
+            description: "Metadata fields contain vowels"
+        );
+
+        public override IEnumerable<IssueTemplate> Templates() => new[]
+        {
+            templateArtistHasVowels
+        };
+
+        private IssueTemplate templateArtistHasVowels = new IssueTemplate
+        (
+            type: IssueTemplate.IssueType.Warning,
+            unformattedMessage: "The {0} field \"{1}\" contains the vowel(s) {2}."
+        );
+
+        public override IEnumerable<Issue> Run(IBeatmap beatmap)
+        {
+            foreach (var issue in GetVowelIssues("artist", beatmap.Metadata.Artist))
+                yield return issue;
+
+            foreach (var issue in GetVowelIssues("unicode artist", beatmap.Metadata.ArtistUnicode))
+                yield return issue;
+
+            foreach (var issue in GetVowelIssues("title", beatmap.Metadata.Title))
+                yield return issue;
+
+            foreach (var issue in GetVowelIssues("unicode title", beatmap.Metadata.TitleUnicode))
+                yield return issue;
+        }
+
+        private IEnumerable<Issue> GetVowelIssues(string fieldName, string fieldValue)
+        {
+            if (fieldValue == null)
+                // Unicode fields can be null if same as respective romanized fields.
+                yield break;
+
+            List<char> matches = vowels.Where(c => fieldValue.ToLower().Contains(c)).ToList();
+
+            if (!matches.Any())
+                yield break;
+
+            yield return new Issue(
+                templateArtistHasVowels,
+                fieldName, fieldValue, string.Join(", ", matches)
+            );
+        }
+    }
+}