benilla-octo/docs/METHOD.md

METHOD — how benilla is built

benilla is a from-scratch World of Warcraft 1.12.1 client in Rust and Bevy. It reads the game's data from the player's own install, speaks the original protocol to any 1.12.1 server, and does not build a server or simulate the game. The reference client is the spec: benilla does what 1.12.1 does, as a modern, idiomatic client.

The rule for every change

A change is right when it makes benilla more like 1.12.1 or fixes a bug, with evidence from the reference, in one small piece, with the gates green. A deviation from the reference is the maintainer's call alone, and each one is written down where it lives: a CVar's Deviates row, a comment naming the reference fact and why we differ. Anything else is a fork.

The loop

1. The reference first. For anything fidelity-defining, get the mechanism from the real client before building: its behaviour, a DBC field, a FrameXML line, a packet capture. The names and shapes under reference/ are the surface benilla tracks.
2. Build it idiomatically. Modern Bevy and Rust, performance woven in from the start. Implement the mechanism well; do not ape a quirk that is a bug.
3. Measure, never eyeball. Timing, delay, ordering and feel are settled with instruments: trace timestamps, byte-derived numbers, a numeric probe. A capture confirms an existence fact; it cannot measure time. Never search for a viewpoint: take the one simplest shot, and if it does not settle the question, hand over a precise script ("log in, look at X, does Y?").
4. Close the loop on the symptom. A bug reported as seen is closed by reproducing it at the reported spot first, fixing, and showing the same instrument clean there plus one adjacent state. Green gates and an existing mechanism are never that evidence.
5. Prove the run before reading the result. A live result is evidence once the run is valid from numbers: preflight banner clean, camera and body where intended, the subject in frame, the window long enough. A negative from an unproven run is not evidence.
6. Commit small and often. Atomic units, explicit paths; main only advances by fast-forward. No "done" and no commit without saying what was verified and how the result was judged.

Hard rules

• Never commit anything from the install. Art, models, sounds, maps, data: the install is read at runtime from a gitignored path, and everyone provides their own. The one exception is interface code: FrameXML and GlueXML run off the player's own patch chain, and the copies already under assets/ui stay until they retire.
• The install is read-only. benilla never writes into the WoW folder: no screenshot, log, cache or scratch file. A hook blocks such a write at the tool call, and scripts/smoke.sh fails a run that leaves the install changed.
• Local state lives in one folder, benilla-config/ beside the binary, and every path to it resolves through crate::local_state. Player settings are CVars persisted as a diff in benilla-config/config.toml.
• UI is stock-first: a window is migrated, not authored. The end state is the stock 1.12 FrameXML executed off the player's own chain. assets/ui does not grow: a test names its files and fails on a new one. A window is built by pointing benilla.toc at the stock file, deleting ours and building the engine verbs it calls, never stubbing one to make the file load.
• A setting's default is the reference's default. Every option boots at the stock 1.12 value. Shipping another value costs an explicit Deviates row with the reason, and a test fails a row that drifts either way.
• Our code is MIT OR Apache-2.0, which is a claim about provenance: no original client code, no bundled assets.

Where things live

• docs/METHOD.md, this file: rules and method. Never state, never a log.
• docs/MAP.md: what is built, generated from the code by scripts/genmap.sh at every land. Read it to orient; never edit or commit it by hand.
• git: the history. No changelogs, no status docs, no "what we did" narratives.
• The code: a comment says what the code does and the 1.12 fact behind it, in a line. No history, no stories.
• .claude/skills/: procedures with steps. probe runs the client unattended against the local server.

Gates

• The land gates: cargo fmt --all -- --check, cargo clippy --workspace --all-targets -- -D warnings, cargo test --workspace, the player build without the dev feature and the engine boot checks, as scripts/gates.sh. wt.sh land runs it on the tree that lands; it is memoized on the tree.
• Per round: scripts/check.sh, scoped to the changed crates and their dependents. Run each gate once per round; tee the output to a file and grep the file.
• A clean run is the fourth gate: scripts/smoke.sh, a live login and logout against the local server. For wire work the gate is a live run with a trace (WOW_MOVE_TRACE=<path>, tags filtered), never a capture: capture mode has no network.
• Platform seams: a cfg(target_os), a [target.'cfg(…)'] dependency, a #[link] or an extern "system" is invisible to the macOS gates. scripts/crosscheck.sh compiles Linux and Windows, and the land worker runs it when the diff touches a seam.
• Vulkan: scripts/vkleg.sh runs the client on Vulkan in a container before a release, because Metal cannot ask what Vulkan validation refuses.
• Hooks enforce only two things: no writes into the install, and the worktree rule on a machine with a pool. Everything else is a gate or discipline.

Worktrees

On a machine with a pool, every session works in its own slot and scripts/wt.sh is the only way to get one. claim <name> at the start; land <name> at the end, which rebases, regenerates the map, runs the full gate chain, fast-forwards and pushes main and releases the slot, one land at a time; release to abandon; status to see the pool. Never the primary checkout, which belongs to no session and stays clean, and never the harness worktree tool or a hand-rolled git worktree add. Work against the slot by path: prefix Bash calls with cd <slot> && and give edits absolute paths under it. No free slot means stop and ask which one to take over, never fall back to the primary. Hooks enforce all of this.

Sessions share the machine, so a kill is scoped to a PID, never to a command pattern: pkill -f "cargo test" takes out every neighbour's gates along with yours.

On a plain clone there is no pool: work on a branch and open a pull request.

The local server

benilla talks to a local vmangos (build 5875); WOW_HOST, WOW_USER, WOW_PASS and WOW_CHAR override the defaults. These bind every session and every agent:

• A probe logs in as its own probe account (probeN for pool-N), never as a player's: a login kicks whoever holds the account.
• Every unattended run says so: WOW_UNATTENDED=1. An agent's run is silent: WOW_NOSOUND=1.
• No unattended combat probes.
• Anything about hostility, reaction colour, nameplates, threat, damage or breath runs with WOW_GM=off.
• Read the preflight banner before debugging anything else.

The mechanics are the probe skill.

Agents in a shared tree

Parallel agents share one working tree: whole-tree git ops (stash, reset --hard, clean -f, a pathless checkout) are forbidden, diagnostics use path-scoped commands, and an agent never gets a tree of its own.