1 files changed, 87 insertions, 0 deletions
diff --git a/src/LivingVillage.Kernel.Tests/RumorTests.fs b/src/LivingVillage.Kernel.Tests/RumorTests.fs
index f52fca9..2cbb189 100644
--- a/src/LivingVillage.Kernel.Tests/RumorTests.fs
+++ b/src/LivingVillage.Kernel.Tests/RumorTests.fs
@@ -91,6 +91,29 @@ module private RumorHarness =
                 rumor.Depth)
         |> String.concat "\n"
 
+    let rumor id tick dayIndex =
+        { Id = RumorId id
+          Tick = tick
+          DayIndex = dayIndex
+          OriginTick = tick
+          Source = NpcId 0
+          Narrator = NpcId 0
+          Receiver = NpcId 1
+          Parent = None
+          Depth = 0
+          Strength = 1.0f }
+
+    let withRumorBudget capacity retentionDays action =
+        let previousCapacity = rumorCapacity
+        let previousRetention = rumorRetentionDays
+        rumorCapacity <- capacity
+        rumorRetentionDays <- retentionDays
+        try
+            action ()
+        finally
+            rumorCapacity <- previousCapacity
+            rumorRetentionDays <- previousRetention
+
 [<TestClass>]
 type RumorTests () =
 
@@ -188,3 +211,67 @@ type RumorTests () =
                   sprintf "rumor id=2 tick=%d origin_tick=0 source=0 narrator=2 receiver=3 parent=1 depth=2 strength=0.250000 path=0,1,2" (2L * ticksPerDay) ]
 
         Assert.AreEqual<string>(expected, Sim.rumorTraceText third)
+
+    [<TestMethod>]
+    member _.TrimWithinCapacityAndFreshWindowIsZeroCopy () =
+        RumorHarness.withRumorBudget 4 3L (fun () ->
+            let rumors =
+                [ RumorHarness.rumor 3L (3L * ticksPerDay) 3L
+                  RumorHarness.rumor 2L (2L * ticksPerDay) 2L
+                  RumorHarness.rumor 1L (1L * ticksPerDay) 1L ]
+            let trimmed = Sim.trimRumors (3L * ticksPerDay) rumors
+            Assert.IsTrue(System.Object.ReferenceEquals(rumors, trimmed), "within budget the list must be returned as-is")
+            Assert.AreEqual<RumorEvent list>(rumors, trimmed))
+
+    [<TestMethod>]
+    member _.TrimCapsToNewestRumors () =
+        RumorHarness.withRumorBudget 4 30L (fun () ->
+            let rumors = List.init 6 (fun index -> RumorHarness.rumor (int64 (5 - index)) (10L * ticksPerDay) 10L)
+            let trimmed = Sim.trimRumors (10L * ticksPerDay) rumors
+            Assert.AreEqual<int>(4, trimmed.Length)
+            let keptIds = trimmed |> List.map (fun rumor -> RumorHarness.rumorId rumor.Id)
+            CollectionAssert.AreEqual([| 5L; 4L; 3L; 2L |], List.toArray keptIds))
+
+    [<TestMethod>]
+    member _.TrimDropsRumorsOlderThanRetentionWindow () =
+        RumorHarness.withRumorBudget 100 3L (fun () ->
+            let rumors =
+                [ RumorHarness.rumor 3L (10L * ticksPerDay) 10L
+                  RumorHarness.rumor 2L (9L * ticksPerDay) 9L
+                  RumorHarness.rumor 1L (6L * ticksPerDay) 6L
+                  RumorHarness.rumor 0L (5L * ticksPerDay) 5L ]
+            let trimmed = Sim.trimRumors (10L * ticksPerDay) rumors
+            let keptIds = trimmed |> List.map (fun rumor -> RumorHarness.rumorId rumor.Id)
+            CollectionAssert.AreEqual([| 3L; 2L |], List.toArray keptIds)
+            Assert.AreEqual<RumorEvent list>(trimmed, Sim.trimRumors (10L * ticksPerDay) trimmed))
+
+    [<TestMethod>]
+    member _.ChatKeepsWorkingSetWithinCapacityAndIdsStayMonotonic () =
+        RumorHarness.withRumorBudget 1 30L (fun () ->
+            let first = RumorHarness.chat 0 1 (RumorHarness.world 0L 4)
+            let second = RumorHarness.chat 1 2 (RumorHarness.readyForChat first)
+            Assert.AreEqual<int>(1, first.Rumors.Length)
+            Assert.AreEqual<int>(1, second.Rumors.Length)
+            let head = second.Rumors |> List.head
+            Assert.AreEqual<int64>(1L, RumorHarness.rumorId head.Id)
+            Assert.AreEqual<RumorId option>(Some(RumorId 0L), head.Parent))
+
+    [<TestMethod>]
+    member _.CappedRumorsWithinCapacitySaveByteIdenticallyToUncapped () =
+        let run capacity =
+            RumorHarness.withRumorBudget capacity 30L (fun () ->
+                let first = RumorHarness.chat 0 1 (RumorHarness.world 0L 4)
+                let second = RumorHarness.chat 1 2 (RumorHarness.readyForChat { first with Tick = ticksPerDay })
+                WorldSave.save second)
+        Assert.AreEqual<string>(run 8, run System.Int32.MaxValue)
+
+    [<TestMethod>]
+    member _.RumorDayIndexMirrorsTickAndSurvivesSaveRoundTrip () =
+        let world = RumorHarness.chat 0 1 (RumorHarness.world 0L 3)
+        let rumor = world.Rumors |> List.head
+        Assert.AreEqual<int64>(rumor.Tick / ticksPerDay, rumor.DayIndex)
+        match WorldSave.load (WorldSave.save world) with
+        | Error failure -> Assert.Fail($"round trip should load: {failure}")
+        | Ok restored ->
+            Assert.AreEqual<RumorEvent list>(world.Rumors, restored.Rumors)
+            Assert.AreEqual<int64>(rumor.DayIndex, (restored.Rumors |> List.head).DayIndex)