vyndr/tests/unit/consensusRuler.test.js

'use strict';

/**
 * consensusRuler + bookRoles — Order Zero Phase 2.
 *
 * These tests lock the properties that make the ruler honest, not just the
 * arithmetic: DFS can never price, different lines can never be averaged,
 * one-sided quotes can never rule, and a fallback can never masquerade as a
 * consensus.
 */

const { consensusFairProb, incumbentFairProb, compareRulers, referenceFairProbs } = require('../../src/services/consensusRuler');
const roles = require('../../src/config/bookRoles');

const q = (book, line, over, under) => ({ book, line, over_odds: over, under_odds: under });

describe('bookRoles — the three-way split', () => {
  it('DFS platforms can never price: excluded, and absent from REFERENCE', () => {
    for (const dfs of roles.DFS_PLATFORMS) {
      expect(roles.REFERENCE_BOOKS.has(dfs)).toBe(false);
      expect(roles.EXCLUDED_FROM_PRICING.has(dfs)).toBe(true);
      expect(roles.roleOf(dfs)).toBe('excluded');
    }
  });

  it('keeps the six PropLine-phantom books in TAKEABLE for the odds-api path', () => {
    for (const b of roles.PHANTOM_ON_PROPLINE) expect(roles.TAKEABLE_BOOKS.has(b)).toBe(true);
  });

  it('pinnacle and the exchanges are reference-only, never takeable', () => {
    for (const b of ['pinnacle', ...roles.EXCHANGES]) {
      expect(roles.REFERENCE_BOOKS.has(b)).toBe(true);
      expect(roles.TAKEABLE_BOOKS.has(b)).toBe(false);
    }
  });

  it('the live ruler is still v1 — v2 is a challenger, not deployed', () => {
    expect(roles.CURRENT_RULER_VERSION).toBe(roles.RULER_V1);
  });
});

describe('consensusRuler — what may price', () => {
  it('a DFS book is ignored even when it is the only book at the line', () => {
    const r = consensusFairProb([q('prizepicks', 1.5, -119, -119)], 1.5, 'over');
    expect(r.source).toBe('none');
    expect(r.fair_prob).toBeNull();
  });

  it('three DFS books do not make a consensus', () => {
    const r = consensusFairProb([
      q('prizepicks', 1.5, -119, -119), q('underdog', 1.5, -118, -118), q('sleeper', 1.5, -120, -120),
    ], 1.5, 'over');
    expect(r.n).toBe(0);
    expect(r.source).toBe('none');
  });

  it('never averages across DIFFERENT lines', () => {
    const r = consensusFairProb([q('novig', 1.5, -104, -104), q('smarkets', 2.5, 200, -240)], 1.5, 'over');
    expect(r.n).toBe(1);
    expect(r.source).toBe('single_book');   // the 2.5 quote is a different market
  });

  it('a one-sided quote cannot rule (it cannot be de-vigged)', () => {
    const r = consensusFairProb([q('novig', 1.5, -104, -104), { book: 'kalshi', line: 1.5, over_odds: -103 }], 1.5, 'over');
    expect(r.n).toBe(1);
  });

  it('counts a book once even if it appears twice', () => {
    const refs = referenceFairProbs([q('novig', 1.5, -104, -104), q('novig', 1.5, -150, 130)], 1.5, 'over');
    expect(refs).toHaveLength(1);
  });
});

describe('consensusRuler — labelling and the median', () => {
  it('n>=2 is a labelled consensus stamped v2', () => {
    const r = consensusFairProb([q('novig', 1.5, -104, -104), q('kalshi', 1.5, -106, -102)], 1.5, 'over');
    expect(r.source).toBe('consensus');
    expect(r.ruler_version).toBe(roles.RULER_V2);
    expect(r.n).toBe(2);
  });

  it('n==1 falls back and is labelled single_book stamped v1 — never called consensus', () => {
    const r = consensusFairProb([q('novig', 1.5, -104, -104)], 1.5, 'over');
    expect(r.source).toBe('single_book');
    expect(r.ruler_version).toBe(roles.RULER_V1);
    expect(r.fair_prob).toBeGreaterThan(0);
  });

  it('uses the MEDIAN so one outlier book cannot drag the ruler', () => {
    const tight = [q('novig', 1.5, -104, -104), q('kalshi', 1.5, -105, -103), q('smarkets', 1.5, -103, -105)];
    const withOutlier = [...tight, q('bovada', 1.5, -400, 300)];
    const a = consensusFairProb(tight, 1.5, 'over').fair_prob;
    const b = consensusFairProb(withOutlier, 1.5, 'over').fair_prob;
    expect(Math.abs(b - a)).toBeLessThan(0.06);   // a mean would move far more
    expect(consensusFairProb(withOutlier, 1.5, 'over').spread).toBeGreaterThan(0.2);
  });

  it('over and under are complementary at a symmetric price', () => {
    const qs = [q('novig', 1.5, -104, -104), q('kalshi', 1.5, -104, -104)];
    const o = consensusFairProb(qs, 1.5, 'over').fair_prob;
    const u = consensusFairProb(qs, 1.5, 'under').fair_prob;
    expect(o + u).toBeCloseTo(1, 3);
  });

  it('no reference quote at all returns null, never a fabricated number', () => {
    const r = consensusFairProb([q('onexbet', 1.5, -110, -110)], 1.5, 'over');
    expect(r.fair_prob).toBeNull();
    expect(r.source).toBe('none');
  });

  it('a null line does not become 0 and match a 0-line quote', () => {
    expect(consensusFairProb([q('novig', 0, -104, -104)], null, 'over').source).toBe('none');
  });
});

describe('consensusRuler — the incumbent it is challenging', () => {
  const LIVE_ALLOWED = new Set(['draftkings', 'fanduel', 'betmgm', 'betrivers', 'pinnacle']);

  it('incumbent is first-row-wins AMONG ADMITTED BOOKS — the allow-list runs first', () => {
    // normalizeProps applies ALLOWED_BOOKS before dedupeProps, so a DFS book
    // sitting first in the raw feed is NOT the incumbent. Getting this wrong
    // overstates the incumbent's badness, which is its own dishonesty.
    const qs = [q('prizepicks', 1.5, -119, -119), q('betmgm', 1.5, -115, -105), q('draftkings', 1.5, -110, -110)];
    const inc = incumbentFairProb(qs, 1.5, 'over', LIVE_ALLOWED);
    expect(inc.book).toBe('betmgm');
    expect(inc.ruler_version).toBe(roles.RULER_V1);
  });

  it('a prop with NO admitted book has no incumbent at all — it is never graded', () => {
    const qs = [q('prizepicks', 1.5, -119, -119), q('novig', 1.5, -104, -104)];
    expect(incumbentFairProb(qs, 1.5, 'over', LIVE_ALLOWED).fair_prob).toBeNull();
  });

  it('compareRulers returns a signed delta in probability points', () => {
    const qs = [q('draftkings', 1.5, -140, 120), q('novig', 1.5, -104, -104), q('kalshi', 1.5, -103, -105)];
    const c = compareRulers(qs, 1.5, 'over', { allowedBooks: LIVE_ALLOWED });
    expect(c.incumbent.book).toBe('draftkings');
    expect(c.consensus.source).toBe('consensus');
    expect(c.delta_pts).toBeLessThan(0);   // dk's favourite priced over above the exchanges
    expect(Math.round(c.delta_pts * 100) / 100).toBeCloseTo((c.consensus.fair_prob - c.incumbent.fair_prob) * 100, 2);
  });

  it('delta is null when either side is unavailable — never 0', () => {
    expect(compareRulers([q('prizepicks', 1.5, -119, -119)], 1.5, 'over', { allowedBooks: LIVE_ALLOWED }).delta_pts).toBeNull();
  });
});