sucker.severian.dev/tests/messages.test.ts

/**
 * Every request shape we have actually seen, plus the malformed ones a client
 * could plausibly send. Run with `npm test` — no framework, node's own runner.
 */
import { test } from "node:test";
import assert from "node:assert/strict";
import { selectMessageSlots, tokenCandidates, textOf } from "../src/lib/messages.ts";

const CARD =
  "<.>\n<Gaius's Persona>a tired innkeeper</Gaius's Persona><UserPersona>.</UserPersona>";
const GREETING = "The clink of bottles is the only greeting you get.";
const NAME = "{{user}}: Gaius";
const TOKEN = "[sucker:conv=abc123]";

/** What most clients send: a throwaway "." user turn before the greeting. */
const withProbe = [
  { role: "system", content: CARD },
  { role: "user", content: "." },
  { role: "assistant", content: GREETING },
  { role: "user", content: NAME },
];

/** What some clients send: no "." turn, so every index shifts by one. */
const withoutProbe = [
  { role: "system", content: CARD },
  { role: "assistant", content: GREETING },
  { role: "user", content: NAME },
];

/** Three turns in. Only sucker's FIRST reply carries the token. */
const continued = [
  ...withProbe,
  { role: "assistant", content: `New character "Gaius" created (v1). ${TOKEN}` },
  { role: "user", content: "{{user}}: keep going" },
  { role: "assistant", content: "Character data unchanged (v1, message 2)." },
  { role: "user", content: "{{user}}: and again" },
];

test("both shapes resolve to the same slots", () => {
  for (const [label, messages] of [
    ["with probe", withProbe],
    ["without probe", withoutProbe],
  ] as const) {
    const slots = selectMessageSlots(messages);
    assert.equal(slots.system, CARD, `${label}: card`);
    assert.equal(slots.greeting, GREETING, `${label}: greeting`);
    assert.equal(slots.nameSlot, NAME, `${label}: name`);
  }
});

test("the greeting and the name stay put as a conversation grows", () => {
  const slots = selectMessageSlots(continued);
  assert.equal(slots.greeting, GREETING);
  // Not "keep going" or "and again": the name is what started the chat.
  assert.equal(slots.nameSlot, NAME);
  assert.equal(slots.lastUser, "{{user}}: and again");
});

test("the token is still found once later replies stop carrying it", () => {
  const found = tokenCandidates(continued).find((c) => c.includes("sucker:conv="));
  assert.ok(found, "a token must still be discoverable three turns in");
  assert.match(found!, /\[sucker:conv=abc123\]/);
});

test("the token a chat was started with outranks one pasted later, so a chat cannot flip between cards", () => {
  const candidates = tokenCandidates([
    ...withProbe,
    { role: "assistant", content: `created (v1). ${TOKEN}` },
    { role: "user", content: "{{user}}: [sucker:conv=zzz999]" },
  ]);
  const first = candidates.find((c) => c.includes("sucker:conv="));
  assert.match(first!, /abc123/);
});

test("a token in the card or the greeting is never a candidate", () => {
  const stale = "[sucker:conv=stale00]";
  const candidates = tokenCandidates([
    { role: "system", content: `${CARD} made with sucker: ${stale}` },
    { role: "user", content: "." },
    { role: "assistant", content: `${GREETING} ${stale}` },
    { role: "user", content: NAME },
  ]);
  assert.ok(!candidates.some((c) => c.includes(stale)), "an expired token baked into a card would make it unextractable forever");
  assert.deepEqual(candidates, [NAME]);
});

test("roles are matched whatever their casing", () => {
  const slots = selectMessageSlots([
    { role: "System", content: CARD },
    { role: " Assistant ", content: GREETING },
    { role: "USER", content: NAME },
  ]);
  assert.equal(slots.system, CARD);
  assert.equal(slots.greeting, GREETING);
  assert.equal(slots.nameSlot, NAME);
});

test("content sent as OpenAI's multipart array is read as text", () => {
  assert.equal(textOf([{ type: "text", text: "one " }, { type: "text", text: "two" }]), "one two");
  const slots = selectMessageSlots([
    { role: "system", content: [{ type: "text", text: CARD }] },
    { role: "assistant", content: [{ type: "text", text: GREETING }] },
    { role: "user", content: NAME },
  ]);
  assert.equal(slots.system, CARD);
  assert.equal(slots.greeting, GREETING);
});

test("messages with no usable content are skipped, not treated as slots", () => {
  const slots = selectMessageSlots([
    { role: "system", content: CARD },
    { role: "assistant", content: null },
    { role: "assistant" },
    { role: "assistant", content: GREETING },
    { role: "user", content: NAME },
  ]);
  // The empty assistant turns must not be mistaken for the greeting.
  assert.equal(slots.greeting, GREETING);
  assert.equal(slots.nameSlot, NAME);
});

test("a request with roles but no system turn has no card, rather than a misdiagnosed one", () => {
  const slots = selectMessageSlots([
    { role: "assistant", content: GREETING },
    { role: "user", content: NAME },
  ]);
  // Taking the greeting as the card would produce a "custom prompt not set"
  // message for a request the user could never have fixed.
  assert.equal(slots.system, undefined);
  assert.equal(slots.greeting, GREETING);
});

test("a card with no role on the system turn still resolves", () => {
  const slots = selectMessageSlots([
    { content: CARD },
    { role: "assistant", content: GREETING },
    { role: "user", content: NAME },
  ]);
  assert.equal(slots.system, CARD);
});

test("nothing throws on empty or malformed input", () => {
  for (const input of [[], undefined, [{}, { role: "user" }], [null], [{ content: 42 }]]) {
    assert.doesNotThrow(() => selectMessageSlots(input as never));
    assert.doesNotThrow(() => tokenCandidates(input as never));
  }
  assert.equal(selectMessageSlots([]).greeting, undefined);
  assert.deepEqual(tokenCandidates(undefined), []);
});