## Summary
About 114 tests skipped on CI because they needed the official client files (`tiledata.mul`, map and multi files). They gave CI no signal, and locally they ran against whichever client a developer had installed. The test hosts now build their own world instead, so every test runs on CI and runs the same on every machine. CI simulation: Server.Tests 837 passed, UOContent.Tests 1131 passed, **0 skipped**.
- **Generated tile data.** The fixtures write a pre-HS `tiledata.mul` from a small invented tile kit (`Server.Tests/Terrain/TestTiles`) and load it through the real `TileData.Load()`. The test hosts no longer read any client directory (`MODERNUO_CLIENT_PATH`, `MODERNUO_TEST_DATA_DIR` and `C:\Ultima Online Classic` are gone from test code). The file is written to `SyntheticData` in each test project's output, overwritten every run and removed by `dotnet clean`.
- **Injected terrain.** `TestTerrain` stamps land and statics into Felucca and Trammel, which share one terrain. Writes after startup must go in a `TestTerrain.Scope()`, which puts back every block it touched and keeps the step cache fresh.
- **Prefab scenes.** Seven named scenes (town, causeway, sewer walkway, coastline, deep sea, map-edge sea, an upstairs room with an L-shaped counter) replace the Britain coordinates the pathing, AI and fishing tests relied on. Each scene-based test asserts its scene is present first, so a missing scene fails instead of passing on flat ground. Stamping all seven takes 3-5 ms.
- **Multi footprints.** Contrived footprints for the three multi IDs content looks up (0x74, 0x7A, 0x0) are seeded through a new internal `MultiData.SetComponents`.
- **Fingerprint.** `StepCacheFile.HashTileDataFile` is extracted so a test can show that a one-flag change to the file changes the fingerprint, while runtime table mutation does not.
### Engine changes
- `TileMatrix.GetLandBlock`/`GetStaticBlock`: on a map without its files, return the block injected with `SetLandBlock`/`SetStaticBlock`, or the default when nothing was injected. Maps with files take the same path as before.
- `MultiData.SetComponents` (internal): registers a footprint without multi files.
### Test changes worth a look
- Values that were properties of real Britain terrain (probes at Z 10, a pinned plain walk mask of 0xC1) are re-pinned to the synthetic plain (Z 0, 0xFF).
- No tests were deleted. The multi walkability and boat-deck tests assert movement behaviour over a footprint, not what a real multi looks like, so they run on the contrived footprints.
- Maps 0 and 1 keep file indexes 0 and 1, and every stamp writes both, rather than sharing one file index. On a map without files the getters never consult the shared-file cache, and its patch bits would hide one facet's injection from the other.
## Test plan
- [x] `dotnet test -p:SolutionDir=... --filter "Category!=Manual"` with the client env vars pointed at an empty directory: 837 + 1131 passed, 0 skipped, 0 failed
- [x] Mutation check: removing the step-cache clear from `TestTerrain` makes the stale-cache tests fail
- [x] CI green on all platforms
Follow-up to #2721. It fixes how the remaining tests behave and changes no production code.
## CI
- Both `dotnet test` steps pass `--filter "Category!=Manual"`. Before this, Manual-tagged tests ran on CI anyway.
- The one surviving movement-throttle latency test is the only coverage of burst forgiveness over a full, wrapped history. It loses its Manual tag, so it runs on CI.
## Tests that passed on CI without testing anything
- **Corpse and throwing tests.** They relied on tiledata for the weapon `Layer`, so on CI the equip silently failed and they asserted against empty lists. They now set `Layer` explicitly and assert the equip took effect. `TestThrown` also pins its own strength and range values, so a shard retuning SoulGlaive no longer breaks them.
- **Healthbar poison rows.** Server.Tests registers no poisons, so every row tested `null`. They now use real poison levels.
- **Account packet tests.** The mock accounts reported `Length` 0, so the character-list tests only ever encoded empty slots. They now encode the real characters.
- **Pathing and AI tests that only mean something on real Trammel/Felucca terrain** are now guarded with `TileDataRequirement.SkipIfMissing()`: Britain desk and clutter scenes, house footprints (no MultiData on CI) and fingerprints. Tests that are valid on flat blank terrain stay unguarded. (A synthetic tiledata fixture to run these on CI is a planned follow-up.)
- **Assertions that couldn't fail now check their claim.** Affected tests include the `DefaultWalker` cache use, cache on/off parity requiring a path, the recorder capability flags, the idle-pet gate, the monthly DST recurrence, the AdvancedSearch `Record.Exception` wrappers, `CanFitItem` with no branch-guarded assert, the Firewall callback, and `Import_NoMap`. The Geometry Parse asserts also now use the same input as their TryParse.
## Shared state
Every test that changes process-wide state now restores it, even when an assert fails:
- **The clock.** A new `TimerWheelScope` saves and restores `Core._tickCount`, `Core._now` and the timer wheel. `SimulatedClockScope` covers decay tests.
- **StepCache settings and caches**, via `StepCacheStateScope`.
- **Network state.** The ManualAllowlist, LoginAllowlist, firewall and BanChannel reporters are restored. Global packet handlers are now registered per test and removed afterwards, so they no longer stay registered for later tests.
- **Data and config tables.** `ArchiveJournal` statics, `TileData.ItemTable`, `ObjectPropertyList.Enabled`, `Core.Expansion` and the localization table are restored. One `MobileStatusVersion` restore was resetting a different expansion than the one the test changed.
- **Entities.** Tests with fixed serials now delete what they create. Fixed mobile serials moved to `World.NewMobile`, because deleting a hard-coded serial could unregister a live entity.
- **Collection race.** `SpiralScanTests` no longer clears the spawn cache from a separate collection that could run in parallel with the cache-manager tests.
- **Shared statics.** Classes reading shared static allowlists joined the sequential collection.
## Duplication
New shared helpers replace copy-pasted harness code:
- **Server.Tests:** `PacketAssert.Sends`, used by about 130 packet tests; `TestClientHarness`, `PersistencePipelineScope`, `NetTestHelpers`, `EntityCleanup` and one `TestMulti`.
- **UOContent.Tests:** `TimerWheelScope`, which also holds one wraparound-safe `RunFor`/`RunUntil`; `AiTestStubs`, which merges six walker copies and five identical creature stubs; `MobileTestHarness`, `CommandTestHarness` and `TempDirectory`.
Dead oracle packet classes are removed.
## Cost
| Test | Before | After |
|---|---|---|
| `VirtualSerialTests` | 1.57s | 2ms (starts near the wrap via reflection instead of drawing ~17.9M serials) |
| Event scheduler recurrence loop | 473ms | 1ms |
| CrowdSec drain | 517ms | 16ms (event-driven instead of a fixed 500ms wait) |
| AuthId tests | 248ms | 99ms (SHA2 except the two GameLogin tests) |
| Container cap tests | 5,000 items | 3,449 / 3,277 (one past each protocol cap) |
| Bulk removal | 100k children | 20k children |
| OPL hash distribution | 60k builds | 10k builds |
## Shard-tuning decoupling
- AI assertions read `ReacquireDelay` and `FollowMoveSpeed` instead of hard-coding production tuning.
- The guard friendly-fire test uses an `AI_Mage` stub instead of WhiteWyrm.
- Argon2 assertions pin the `argon2id` variant and `v=19` but read the cost parameters from the configured hasher.
## Tests
| Run | Server.Tests | UOContent.Tests |
|---|---|---|
| With client files | 812 pass | 1,123 pass |
| Without client files (CI simulation) | 800 pass, 12 skip | 1,021 pass, 102 skip |
- The UOContent fixture reads `MODERNUO_TEST_DATA_DIR`; Server.Tests reads `MODERNUO_CLIENT_PATH`.
- The 15 new UOContent skips are the map-dependent guards above.
- Total run time with client files is about 5s, down from about 8s.
## Summary
`Find_TwoPathfindsOverlappingChunks_PromoteToBuildOnSecondFind` fails intermittently in CI with `second Find through overlapping chunks must promote (got 0 builds)`.
**Cause:** `SecondTouchAfterWindow_RestartsTheCount` and `TwoFindsAcrossTheWindow_DoNotPromote` set `StepCache.Instance.MissPromotionWindowMs = 1` and never restore it, and `Clear()` does not reset it. Both classes share the `Sequential Pathfinding Tests` collection, so when a lifecycle test runs first, the promotion test's two Finds have to land within 1 ms of each other. On Linux, `Environment.TickCount` moves in coarse steps of several ms, so even a sub-millisecond test can see the window lapse. The second Find then restarts the miss count instead of promoting. On Windows the ~15.6 ms tick nearly always reads the same value for both Finds, which is why it didn't reproduce locally.
**Fix (tests only):**
- `StepCacheLifecycleTests` implements `IDisposable` and restores the window after each test.
- The promotion test sets the window it depends on (30 s) instead of inheriting it.
## Test plan
- [x] Reproduced deterministically: with a temporary 20 ms sleep between the two Finds, the test fails whenever the lifecycle tests run first and passes when run alone
- [x] With the sleep still in, the test passes with the Dispose restore alone and with both fixes
- [x] All pathfinding tests pass (123/123) with the sleep removed
## Problem
Three coupled issues, each hiding the next:
1. **CI passed despite failing tests, with no test logs.** ([example run](https://github.com/modernuo/ModernUO/actions/runs/28639143286/job/84931544255) — the `Test` step produced zero output and the job went green.)
2. **Two `EmitsLowerStatReqWhenPassed` tests** fail with `KeyNotFoundException: '1060435'`.
3. Once CI actually ran the tests, **~337 UOContent tests failed** with `FileNotFoundException: tiledata.mul was not found` — the test bootstrap force-loaded copyrighted client data that CI doesn't have.
## Root causes & fixes
### 1. CI ran zero tests (`fix(ci)`)
The `Test` step ran `dotnet test --no-restore`, but the `Build` step only restores/builds `Application` — never the test projects. Without a restore, the test projects have no `project.assets.json`, so `Microsoft.NET.Test.Sdk`'s targets aren't imported, they aren't recognized as test projects, and `dotnet test` runs the `VSTest` target against **zero** projects → no output, **exit 0**.
- Both jobs now run `dotnet test --logger trx --results-directory ./TestResults` (test projects restore and run) **plus a guard** that fails the job if no `.trx` is produced — a permanent backstop against silent zero-test passes.
### 2. Impossible OPL tests (`fix(ci)` + `test(opl)`)
#2501 deliberately emits `LowerStatReq` (`1060435`) **inline in each item**, not in `GetProperties`. A follow-up "fix" dropped the `lowerStatReq:` argument to make the tests compile but left the assertions expecting `1060435`.
- Removed the two impossible tests, then removed the **entire `Tests/PropertyList/` OPL attribute set** from #2501: these assert exact cliloc/value/order of OPL emission per item base — a one-time proof of the #2501 rewire, now a permanent tax on modding (any admin reorder/value change/added line reddens the build). The one non-trivial case (LowerStatReq) is what just broke, because the test was wrong. Inline emission stays covered by the `BaseArmor`/`BaseClothing` tests.
### 3. Tile-data-dependent tests crashed CI (`test(uocontent)`)
UOContent.Tests' collection-fixture constructor force-loaded `tiledata.mul` unconditionally. On CI (no client files) it threw, and xUnit failed **every test in the collection** with the same error — mostly collateral (packet/scheduler/spawner tests that don't need tile data).
- Mirror Server.Tests' graceful pattern: `TestServerInitializer` probes for `tiledata.mul` and only loads tile/multi data (and runs the tile-dependent configure steps) when present, exposing `TileDataLoaded` so the fixture no longer throws.
- Add a shared `TileDataRequirement.SkipIfMissing()` guard and apply it to exactly the **31** pathfinding/multi/AI tests that genuinely need real tile data (`[SkippableFact]`/`[SkippableTheory]`).
## Verification (all local)
| Scenario | Server.Tests | UOContent.Tests |
|---|---|---|
| **Client data absent (CI)** | 726 pass, 17 skip, **0 fail** | 469 pass, 32 skip, **0 fail** |
| **Client data present (dev)** | 726 pass, 0 skip, **0 fail** | 501 pass, 0 skip, **0 fail** |
- Full `dotnet test` exits **0**; TRX files produced; the no-test guard trips (exit 1) only when zero `.trx` are produced.
## Summary
Closes the Cold-cache regression flagged in PR #2450. `StepCache.TryGetMask` no longer eagerly runs `BuildChunk` on the first miss for a chunk that isn't in a `.swb` lazy reader. Instead it returns `Fallthrough_NotBuilt` and the caller (`BitmapAStarAlgorithm`) takes the per-cell slow path. The chunk is only promoted to the bitmap fast path after the **second** miss within a 30-second window, filtering single-touch pass-throughs.
This makes BitmapAStar's worst-case (cold cache + short hops) collapse from **12–47× slower** than FastAStar to **roughly the same**, which is the floor the slow path can deliver. Steady-state warm performance (the actual deliverable) is unchanged from PR-5 — it was always the cache fast path.
## The pet-follow scenario this fixes
A mounted player at ~4 tiles/sec with a pet/hireable following will trigger an NPC pathfind every 100–300 ms. Each pathfind is 1–6 tiles. As the player crosses chunk boundaries (~4 sec/chunk), the pet's first pathfind in the new chunk under the previous behavior triggered a full ~700 µs `BuildChunk` for a chunk the player would leave shortly after. At 50–100 mobiles per shard, this exceeded the 8 ms tick budget. PR-5 BDN data showed scenarios 6–9 (2–8 tile NPC perception) at 2,300–3,700 µs Cold vs FastAStar's 80–200 µs.
Under the new gate:
- First miss → `Fallthrough_NotBuilt` → caller uses slow path (~30–50 µs short path). No `BuildChunk`. No allocation.
- Player keeps moving → chunk never gets a second touch within window → never promoted, no rot.
- NPC patrolling a fixed territory → repeatedly hits the same chunks → second touch within window → promote → cache fast path on subsequent calls.
## What changed
- **`CacheHitKind.Fallthrough_NotBuilt = 6`** + **`CacheStats.FallthroughNotBuilt`** counter. `IsHit=false`, so the caller routes to slow path.
- **`StepCache._chunkMissTracker`** — `Dictionary<long, ChunkMissState>` capped at 4096 entries. State is `(byte missCount, uint lastMissTickStamp)` keyed by chunk key. Window-expired entries reset count to 1; capacity overflow prunes window-old entries first.
- **`StepCache.MissPromotionThreshold`** (default `2`) and **`StepCache.MissPromotionWindowMs`** (default `30_000`) — tunable, can be wired through `ServerConfiguration` if shards want different policy. Setting threshold to `1` restores legacy eager-build behavior (used by tests that prime chunks via single `TryGetMask` call).
- **`StepCache.TryGetMask` miss branch** — try lazy reader first (file-loaded chunks bypass the tracker entirely; an `.swb` represents an explicit prior decision to keep the chunk warm). Otherwise consult the tracker.
- **`BitmapAStarAlgorithm.GetSuccessorsSlowPath`** now layers `IsBlockedByDynamic` on top of `CalcMoves.CheckMovement`. Previously the slow path only ran for `CanFly` creatures and rare cache fallthroughs — `CheckMovement` doesn't iterate same-cell mobiles, so the bitmap fast path's `IsBlockedByDynamic` was the only mobile-blocking check. Now first-touch pathfinds run through the slow path, so the gap had to close.
## Tests
50 pathfinding tests pass (was 47). New / updated:
- **`TryGetMask_FirstTouchOnUnbuiltChunk_DefersBuildAndReturnsFallthrough`** — single TryGetMask call returns `Fallthrough_NotBuilt`, no chunk built, no allocation.
- **`TryGetMask_SecondTouchWithinWindow_PromotesAndBuilds`** — second call inside the 30s window builds + serves.
- **`TryGetMask_SecondTouchAfterWindow_RestartsCounterAndDefers`** — second call outside the window restarts the count, returns Fallthrough again.
- **`TryGetMask_DistinctChunks_TrackedIndependently`** — counters are per-chunk; one touch on each of two adjacent chunks both stay in fallthrough.
- **`LazyReaderHit_BypassesMissTrackerOnFirstTouch`** — open `.swb` + first touch hits without consulting the tracker. Production with `.swb` loaded skips the gate entirely.
- **`MultisVersion_Bump_TriggersDirtyRebuild`** — updated to reflect the new 3-step flow (Fallthrough → Miss_NotBuilt → Miss_DirtyRebuild).
- Tests that prime chunks via a single `TryGetMask` call (multi-Z, Tier4, lifecycle, parity, BitmapAStar uses-cache) set `MissPromotionThreshold = 1` to opt into eager behavior.
## Expected BDN impact
The Cold column from PR-5's BDN should change as follows once the bench's submodule pointer is updated to this branch:
| # | Scenario | Cold (PR-5) | Cold (PR-6 expected) | FastAStar Cold |
|--:|-----------------|-------------:|---------------------:|---------------:|
| 2 | sewer corridor | 1,627 µs | ~36 µs | 36 µs |
| 4 | causeway | 1,533 µs | ~39 µs | 39 µs |
| 6 | pet 2-tile | 2,364 µs | ~80 µs | 81 µs |
| 8 | npc 5-tile | 3,708 µs | ~140 µs | 141 µs |
| 9 | npc 8-tile | 2,386 µs | ~200 µs | 197 µs |
WarmNoFile and LazyWarm rows should be unchanged — they were always cache-warm. The miss tracker only fires when neither resident chunks nor the lazy reader can satisfy the request.
## Future work (not in this PR)
- **Background-thread bake**: builds outside the game thread so even promoted chunks don't pay the 700 µs build cost on the main thread. Rule 10 (no Task.Run) applies, so this needs careful design — the bake is a pure data transform but main-thread synchronization on chunk-state transitions has to be threaded through. Defer to a follow-up.
- **Long-traverse BDN scenario**: a multi-Find benchmark simulating 50 pet repaths across chunk transitions. Requires restructuring the bench harness; the existing 10-scenario corpus + Cold provider already exercises the gate.
- **Swim sourceZ bake**: scenario 5 (sea serpent) shows 56 B alloc on warm paths because the cache's SourceZ is computed under default-walker rules. Swim creatures fall through to slow path. Independent of this PR.
## Summary
Builds on PR #2446's cache-direct A*. The previous PR conservatively routed players + creatures with capability flags entirely through the slow path. This PR pushes that line: most mobile classes now use the cache, with the right rule set layered on top per-mobile, and the cache fast-path now does the dynamic items / mobiles check that PR #2446 had silently skipped.
## What changed
- **Non-GM players** now use the cache. Diagonal corner-cut applies the strict AND-rule (BOTH cardinal partners walkable) by reading the same source-cell mask byte the creature OR-rule reads — both rules are evaluable from one byte.
- **Creatures with `CanOpenDoors` / `CanMoveOverObstacles`** now use the cache. Reading `MovementImpl` confirmed those flags only affect dynamic items, never static tiles, so they were over-conservatively excluded before.
- **Swim creatures** now use the cache via a capability overlay. `StepProbe` bakes a second rule set (`canSwim=true, cantWalk=true`) producing `WetMask` + `SwimZ_*`. The algorithm composes `effectiveMask = (walkMask & !cantWalk) | (wetMask & canSwim)` per direction; walk Z preferred when both apply.
- **Dynamic-obstacle pass.** Cache fast-path now mirrors `MovementImpl`'s per-cell items + mobiles collision check (`GetItemsAt` / `GetMobilesAt` at the target cell, with `CanOpenDoors` / `CanMoveOverObstacles` / spell-field overrides). This closes a correctness gap from PR #2446 — the cache fast-path was silently skipping dynamic obstacles entirely.
- **`StepCache.TryGetMask` returns `StepMask` struct** instead of 11 out parameters. `HitKind` rolls into the struct with an `IsHit` accessor. Sets up wet/swim without ballooning the call site.
- **`StepChunk.MultiZCells` is lazy-init.** Most chunks are entirely single-Z; allocating the 32-byte bitmap up-front wasted ~256KB at full cap.
- **Admin commands.** `[PathCacheStats` (resident chunks + hit/miss/eviction counters) and `[PathCacheClear` (drop everything, zero counters).
- **Feature flag.** `bitmap_pathfinding_cache` (default true) gates the cache fast-path. Flipped off, every cell expansion routes to `MovementImpl` — equivalent to PR #2446's slow-path-only behavior. Safety net for shipping the new behavior.
`RequiresSlowPath` shrinks to just `CanFly` — flying creatures Z-jump arbitrarily, which the cache's static-Z model can't accommodate.
## Summary
Replaces `FastAStarAlgorithm` with `BitmapAStarAlgorithm`: one cache lookup per cell expansion (8-direction mask + per-direction destination Z) instead of 8 separate `MovementImpl.CheckMovement` calls. Adds the supporting cache infrastructure to back it.
Public API unchanged — `MovementPath` / `Mobile.Move` / `CalcMoves.Find` return the same shapes; the algorithm swap is internal.
## What's in this PR
- **`BitmapAStarAlgorithm`** — A* that issues one `StepCache.TryGetMask` call per cell expansion. Inline fallthrough to the per-cell slow path for multi-Z, off-map, source-Z mismatch, and non-default walkers.
- **`StepCache`** — singleton chunk store keyed by `(mapId, chunkX, chunkY)`. Lazily built on first query, invalidated by `Sector.MultisVersion` mismatch, memory-bounded by sampled probabilistic LRU.
- **`StepProbe`** — computes static-only walkability for a single cell, mirroring `MovementImpl.Check` minus the item / mobile collision phases.
- **`StepMask` / `StepChunk`** — value / storage types for the per-cell results.
- **`CacheEvictionTimer`** — periodic cap backstop (60s interval; early-returns when not over cap).
- **`Map.Sector.MultisVersion`** promoted to `public` so the cache can detect dynamic-static invalidations cheaply.
## Eviction strategy
Sampled probabilistic LRU (Redis-style). Per eviction, sample 5 random keys from a parallel `List<long>` kept in lockstep with the chunk dictionary; evict the oldest of the sample via swap-and-pop. O(1) per eviction regardless of resident count, so sustained cap pressure has no perpetual perf hit.
## Capability handling (interim)
Non-default walkers (non-GM players, creatures with `CanSwim` / `CanFly` / `CanOpenDoors` / `CanMoveOverObstacles`) route entirely through the per-cell slow path via `BitmapAStarAlgorithm.GetSuccessorsSlowPath`. The 2-pass design (cache + capability overlay + dynamic-obstacle pass) lands in the follow-up PR.
Kamron Batman