Begin Hnefatafl from the game kit

deploy/replay-ledgers.ts

@@ -0,0 +1,74 @@
+// Replays every ledger in a directory with THIS checkout's engine and, when
+// a server address is given, compares the result with what that server is
+// showing for the room: the round reached and the outcome. A ledger the
+// engine cannot replay, or replays differently, is reported and fails the
+// run. Used by deploy/verify-ledgers.sh.
+//   tsx deploy/replay-ledgers.ts <ledger-dir> [https://host]
+
+import { readdirSync, readFileSync } from 'node:fs';
+import { join } from 'node:path';
+import { game } from '../src/lib/game';
+import type { SeatId } from '../src/lib/game/spec';
+
+interface Seat {
+	id: SeatId;
+	name: string;
+	bot: boolean;
+}
+
+const [dir, host] = process.argv.slice(2);
+if (!dir) {
+	console.error('usage: replay-ledgers.ts <ledger-dir> [https://host]');
+	process.exit(2);
+}
+
+async function main(): Promise<void> {
+	const files = readdirSync(dir).filter((f) => f.endsWith('.jsonl'));
+	let failures = 0;
+	for (const file of files) {
+		const code = file.slice(0, -'.jsonl'.length);
+		const lines = readFileSync(join(dir, file), 'utf8')
+			.split('\n')
+			.filter((l) => l.trim())
+			.map((l) => JSON.parse(l));
+		const seats: Seat[] = [];
+		let state: ReturnType<typeof game.create> | null = null;
+		let turns = 0;
+		try {
+			for (const line of lines) {
+				if (line.t === 'seat') seats.push(line);
+				else if (line.t === 'unseat') seats.splice(seats.findIndex((s) => s.id === line.id), 1);
+				else if (line.t === 'start') state = game.create(Object.fromEntries(seats.map((s) => [s.id, s.name])), line.seed, line.rules ?? 1);
+				else if (line.t === 'turn' && state) {
+					state = game.resolve(state, line.inputs);
+					turns += 1;
+				}
+			}
+		} catch (e) {
+			console.log(`${code}: REFUSED at turn ${turns + 1}: ${e instanceof Error ? e.message : String(e)}`);
+			failures += 1;
+			continue;
+		}
+		const outcome = state ? game.over(state) : null;
+		let verdict = state ? `${turns} turns, ${outcome ? 'over' : 'in play'}` : 'not started';
+		if (host && state) {
+			// The gallery's view carries the round and the outcome, which is all the comparison needs.
+			const res = await fetch(`${host}/api/rooms/${code}`);
+			if (!res.ok) {
+				verdict += `, server ${res.status}`;
+			} else {
+				const theirs = (await res.json()) as { turn: number | null; over: { winner: SeatId | null } | null };
+				const same = theirs.turn === game.turn(state) && (theirs.over?.winner ?? null) === (outcome?.winner ?? null);
+				if (!same) {
+					failures += 1;
+					verdict += `, DIFFERS from the server (server round ${theirs.turn}, local round ${game.turn(state)})`;
+				} else verdict += ', matches the server';
+			}
+		}
+		console.log(`${code}: ${verdict}`);
+	}
+	console.log(`${files.length} ledger${files.length === 1 ? '' : 's'}, ${failures} problem${failures === 1 ? '' : 's'}`);
+	process.exit(failures ? 1 : 0);
+}
+
+void main();