feat: seedable dice core with pools

src/dice/roller.js

@@ -0,0 +1,18 @@
+export function expandDice(diceSpecs) {
+  const out = [];
+  for (const d of diceSpecs) {
+    const count = d.count ?? 1;
+    for (let i = 0; i < count; i++) out.push({ sides: d.sides });
+  }
+  return out;
+}
+
+export function rollDie(sides, rng) {
+  return Math.floor(rng() * sides) + 1;
+}
+
+export function rollPool(diceSpecs, rng) {
+  const results = expandDice(diceSpecs).map((d) => ({ sides: d.sides, value: rollDie(d.sides, rng) }));
+  const total = results.reduce((s, r) => s + r.value, 0);
+  return { results, total };
+}