Add rain and snow minutes to the morning commute.

Day plans take a precomputed extra; Ai does not know precipitation.

Co-authored-by: Cursor <cursoragent@cursor.com>

tests/HSchool.Ai.Tests/WalkingTests.cs

@@ -133,6 +133,61 @@ public class WalkingTests
         Assert.True(first.AppearAt < DateTime.SpecifyKind(TuesdayLesson.Date.Add(new TimeSpan(8, 30, 0)), DateTimeKind.Utc));
     }
 
+    [Fact]
+    public void SnowMinutes_AppearEarlierThanClear()
+    {
+        var (clear, snow, extra) = PlansWithExtra(catalog => catalog.BehaviorRules!.CommuteSnowMinutes);
+        Assert.Equal(6, extra);
+        Assert.Equal(clear.AppearAt!.Value.AddMinutes(-extra), snow.AppearAt);
+    }
+
+    [Fact]
+    public void RainMinutes_AppearEarlierThanClear()
+    {
+        var (clear, rain, extra) = PlansWithExtra(catalog => catalog.BehaviorRules!.CommuteRainMinutes);
+        Assert.Equal(3, extra);
+        Assert.Equal(clear.AppearAt!.Value.AddMinutes(-extra), rain.AppearAt);
+    }
+
+    [Fact]
+    public void Clear_MatchesOmittedExtraArgument()
+    {
+        var (catalog, map) = Fixtures.Vanilla();
+        var (walks, pupil, schoolClass, table) = ComingPupil(catalog, map);
+        var implied = DayPlans.Build(catalog, walks, pupil, schoolClass, table, TuesdayLesson, weekDays: 5, schoolSeed: 9);
+        var explicitZero = DayPlans.Build(
+            catalog, walks, pupil, schoolClass, table, TuesdayLesson, weekDays: 5, schoolSeed: 9, extraCommuteMinutes: 0);
+
+        Assert.Equal(implied, explicitZero);
+        Assert.True(implied.Comes);
+    }
+
+    [Fact]
+    public void SameSeedAndSnowMinutes_YieldTheSameAppearAt()
+    {
+        var (catalog, map) = Fixtures.Vanilla();
+        var (walks, pupil, schoolClass, table) = ComingPupil(catalog, map);
+        var extra = catalog.BehaviorRules!.CommuteSnowMinutes;
+        var first = DayPlans.Build(
+            catalog, walks, pupil, schoolClass, table, TuesdayLesson, weekDays: 5, schoolSeed: 9, extra);
+        var second = DayPlans.Build(
+            catalog, walks, pupil, schoolClass, table, TuesdayLesson, weekDays: 5, schoolSeed: 9, extra);
+
+        Assert.Equal(first.AppearAt, second.AppearAt);
+        Assert.True(first.Comes);
+    }
+
+    [Fact]
+    public void Sources_DoNotMentionPrecipitation()
+    {
+        var root = Path.Combine(Fixtures.RepoRoot(), "src", "HSchool.Ai");
+        foreach (var path in Directory.EnumerateFiles(root, "*.cs"))
+        {
+            var text = File.ReadAllText(path);
+            Assert.DoesNotContain("Precipitation", text, StringComparison.Ordinal);
+        }
+    }
+
     [Fact]
     public void Assembly_DoesNotReferenceArchAspNetOrSockets()
     {
@@ -153,4 +208,29 @@ public class WalkingTests
             Assert.DoesNotContain("DateTime.UtcNow", text, StringComparison.Ordinal);
         }
     }
+
+    private static (DayPlan Clear, DayPlan Weather, int Extra) PlansWithExtra(Func<DefCatalog, int> extraOf)
+    {
+        var (catalog, map) = Fixtures.Vanilla();
+        var (walks, pupil, schoolClass, table) = ComingPupil(catalog, map);
+        var extra = extraOf(catalog);
+        var clear = DayPlans.Build(catalog, walks, pupil, schoolClass, table, TuesdayLesson, weekDays: 5, schoolSeed: 9);
+        var weather = DayPlans.Build(
+            catalog, walks, pupil, schoolClass, table, TuesdayLesson, weekDays: 5, schoolSeed: 9, extra);
+        return (clear, weather, extra);
+    }
+
+    private static (WalkGraph Walks, Person Pupil, SchoolClass SchoolClass, Timetable Table) ComingPupil(
+        DefCatalog catalog,
+        MapLayout map)
+    {
+        var walks = WalkGraph.Build(catalog, map);
+        var roster = RosterGenerator.Generate(catalog, map, schoolSeed: 9, "Russia", TuesdayLesson);
+        var pupil = roster.People.First(person => person.IsStudent);
+        var schoolClass = roster.Classes.First(row => row.Id == pupil.ClassId);
+        var table = new Timetable(
+            [new LessonPlacement(schoolClass.Id, "Mathematics", "t1", schoolClass.RoomId, Day: 1, Period: 1)],
+            []);
+        return (walks, pupil, schoolClass, table);
+    }
 }

tests/HSchool.Content.Tests/BehaviorDefTests.cs

@@ -97,6 +97,42 @@ public class BehaviorDefTests
         Assert.Contains("lessonNoTextbookFactor", error.Message, StringComparison.Ordinal);
     }
 
+    [Fact]
+    public void MissingCommuteWeatherMinutes_DefaultToZero()
+    {
+        var catalog = _loader.Load(
+            [CatalogLoader.CorePackId],
+            [
+                PackDocuments.Def(
+                    CatalogLoader.CorePackId,
+                    "behavior",
+                    "rules",
+                    """{ "defName": "Behavior", "needThreshold": 0.35, "lessonSkillPerHour": 0.05, "commuteSlackMin": 0, "commuteSlackMax": 6, "switchMargin": 0.15 }"""),
+            ]);
+
+        Assert.NotNull(catalog.BehaviorRules);
+        Assert.Equal(0, catalog.BehaviorRules.CommuteRainMinutes);
+        Assert.Equal(0, catalog.BehaviorRules.CommuteSnowMinutes);
+    }
+
+    [Theory]
+    [InlineData("commuteRainMinutes")]
+    [InlineData("commuteSnowMinutes")]
+    public void NegativeCommuteWeatherMinutes_FailsTheCatalog(string field)
+    {
+        var error = Assert.Throws<ContentLoadException>(() => _loader.Load(
+            [CatalogLoader.CorePackId],
+            [
+                PackDocuments.Def(
+                    CatalogLoader.CorePackId,
+                    "behavior",
+                    "rules",
+                    $$"""{ "defName": "Behavior", "{{field}}": -1 }"""),
+            ]));
+
+        Assert.Contains("cannot be negative", error.Message, StringComparison.OrdinalIgnoreCase);
+    }
+
     [Fact]
     public void NegativeApparelWear_FailsTheCatalog()
     {

tests/HSchool.Simulation.Tests/WeatherTests.cs

@@ -63,6 +63,16 @@ public class WeatherTests
         }
     }
 
+    [Fact]
+    public void ExtraCommuteMinutes_FollowTheStreet()
+    {
+        var rules = Vanilla().BehaviorRules!;
+        Assert.Equal(6, new OutdoorWeather(-5f, Precipitation.Snow).ExtraCommuteMinutes(rules));
+        Assert.Equal(3, new OutdoorWeather(8f, Precipitation.Rain).ExtraCommuteMinutes(rules));
+        Assert.Equal(0, new OutdoorWeather(8f, Precipitation.None).ExtraCommuteMinutes(rules));
+        Assert.Equal(0, new OutdoorWeather(-5f, Precipitation.Snow).ExtraCommuteMinutes(null));
+    }
+
     [Fact]
     public void SkipEmpty_SetsMondayMorningWeather_NotSaturdays()
     {