Build a Cited Assistant That Can Abstain

import assert from "node:assert/strict";

const sources = [
  { id: "A3", key: "admission", audience: "public", from: "2026-01-01", to: null,
    rule: "one-payment", label: "Demo Fees v3 / Admission fee",
    text: "Admission fees must be paid in one payment, including the evening program." },
  { id: "T3", key: "tuition", audience: "public", from: "2026-01-01", to: null,
    rule: "two-installments", label: "Demo Fees v3 / Tuition",
    text: "Tuition may be paid in two installments. This rule does not cover the admission fee." },
  { id: "A2", key: "admission", audience: "public", from: "2025-01-01", to: "2025-12-31",
    rule: "two-installments", label: "Demo Fees v2 / Admission fee",
    text: "Admission fees may be paid in two installments." },
  { id: "M1", key: "internal_exception", audience: "manager", from: "2026-01-01", to: null,
    rule: "manager-review", label: "Internal exception procedure",
    text: "Managers review exceptional fee arrangements through the internal process." }
];

function answer(key, actor, asOf, registry = sources) {
  if (!actor || !["public", "manager"].includes(actor.role)) {
    return { state: "ESCALATED", message: "Ask the policy owner for access.", citations: [] };
  }
  if (!/^\d{4}-\d{2}-\d{2}$/.test(asOf) ||
      !Number.isFinite(Date.parse(asOf)) || new Date(asOf).toISOString().slice(0, 10) !== asOf) {
    return { state: "ESCALATED", message: "The evaluation date needs correction.", citations: [] };
  }
  if (key === "approve_exception") {
    return { state: "ESCALATED", message: "Only the policy owner may decide an exception.", citations: [] };
  }
  // Permission and date filters run before selecting candidates by question key.
  const eligible = registry.filter(s =>
    (s.audience === "public" || actor.role === "manager") &&
    s.from <= asOf && (s.to === null || asOf <= s.to));
  const hits = eligible.filter(s => s.key === key);
  if (!hits.length) {
    return { state: "ABSTAINED", message: "No approved source available for this question; ask the policy owner.", citations: [] };
  }
  if (new Set(hits.map(s => s.rule)).size > 1) {
    return { state: "ESCALATED", message: "Active sources conflict; ask the policy owner.", citations: [] };
  }
  // The fixture answer copies a complete approved clause, rather than adding claims.
  const source = hits[0];
  return { state: "ANSWERED", answer: source.text, asOf,
    citations: [{ id: source.id, label: source.label, excerpt: source.text }] };
}

const actor = { role: "public" }; // trusted test fixture, not a request parameter
const tests = [
  ["admission", "ANSWERED", "A3"],
  ["tuition", "ANSWERED", "T3"],
  ["scholarship", "ABSTAINED", null],
  ["approve_exception", "ESCALATED", null],
  ["internal_exception", "ABSTAINED", null]
];
for (const [key, state, citation] of tests) {
  const result = answer(key, actor, "2026-10-05");
  assert.equal(result.state, state);
  assert.equal(result.citations[0]?.id ?? null, citation);
  console.log(key, JSON.stringify(result));
}
console.log("Five local cases passed; no model request or approval was made.");