vyndr/tests/unit/probabilityContract.test.js

'use strict';

/**
 * THE CONTRACT'S ONE JOB: never answer "the calibrator is not supported here"
 * with a number we have already measured to be wrong.
 */
const pc = require('../../src/services/model/probabilityContract');
const svc = require('../../src/services/model/probabilityContractService');
const reg = require('../../src/services/model/calibrationRegistry');

const ERA = 'engine1@2026-08-07-fullwindow';
const read = (p, over = {}) => ({ sport: 'mlb', stat: 'hits', model_version: ERA, p_win: p, ...over });
// A stand-in shaped like the real map: monotone, flattening, correcting downward.
const iso = (p) => Math.round((0.42 + 0.26 * p) * 1000) / 1000;
const deps = { estimate: iso };

describe('probability object and states', () => {
  it('serves a calibrated number inside certified raw support', () => {
    const r = pc.resolve(read(0.65), deps);
    expect(r.probability_state).toBe(pc.STATE.CERTIFIED_CALIBRATED);
    expect(r.served_probability).toBe(iso(0.65));
    expect(pc.isCertified(r)).toBe(true);
  });

  it('NO RAW FALLBACK — an uncertified region serves no number at all', () => {
    for (const p of [0.85, 0.90, 0.95, 0.99]) {
      const r = pc.resolve(read(p), deps);
      expect(r.probability_state).toBe(pc.STATE.UNCERTIFIED);
      expect(r.served_probability).toBeNull();
      // the specific defect: served must not silently become the raw value
      expect(r.served_probability).not.toBe(p);
    }
  });

  it('raw probability is preserved in every state, including refusals', () => {
    for (const p of [0.45, 0.55, 0.85, 0.95]) {
      expect(pc.resolve(read(p), deps).raw_model_probability).toBe(p);
    }
    expect(pc.resolve(read(0.9), deps).raw_model_probability).toBe(0.9);
  });

  it('a different model era is a different forecaster — VERSION_MISMATCH, no number', () => {
    const r = pc.resolve(read(0.65, { model_version: 'engine1@2026-07-20' }), deps);
    expect(r.probability_state).toBe(pc.STATE.VERSION_MISMATCH);
    expect(r.served_probability).toBeNull();
  });

  it('another stat or sport is UNSUPPORTED, never quietly served', () => {
    for (const o of [{ stat: 'total_bases' }, { stat: 'rbi' }, { sport: 'wnba' }, { sport: 'nba' }]) {
      const r = pc.resolve(read(0.65, o), deps);
      expect(r.probability_state).toBe(pc.STATE.UNSUPPORTED);
      expect(r.served_probability).toBeNull();
    }
  });

  it('an absent or out-of-range raw probability is INVALID, not coerced', () => {
    for (const p of [null, undefined, NaN, -0.1, 1.4, 'x']) {
      const r = pc.resolve(read(p), deps);
      expect(r.probability_state).toBe(pc.STATE.INVALID);
      expect(r.served_probability).toBeNull();
    }
  });

  it('refuses when the estimator declines inside its own support', () => {
    const r = pc.resolve(read(0.65), { estimate: () => null });
    expect(r.probability_state).toBe(pc.STATE.UNCERTIFIED);
    expect(r.served_probability).toBeNull();
  });

  it('the certified band is half-open and expressed in the RAW input domain', () => {
    expect(pc.inCertifiedRawBand(pc.MLB_HITS.certified_bands, 0.50)).toBe(true);
    expect(pc.inCertifiedRawBand(pc.MLB_HITS.certified_bands, 0.799)).toBe(true);
    expect(pc.inCertifiedRawBand(pc.MLB_HITS.certified_bands, 0.80)).toBe(false);
    expect(pc.inCertifiedRawBand(pc.MLB_HITS.certified_bands, 0.499)).toBe(false);
  });
});

describe('the served function is non-decreasing across its support', () => {
  it('never moves backwards as raw confidence rises', () => {
    let prev = null;
    for (let x = 0.30; x <= 1.0001; x += 0.001) {
      const p = Math.round(x * 1000) / 1000;
      const r = pc.resolve(read(p), deps);
      if (r.served_probability == null) continue;
      if (prev != null) expect(r.served_probability).toBeGreaterThanOrEqual(prev);
      prev = r.served_probability;
    }
  });

  it('a gap is an absence, not a step down to raw', () => {
    const inside = pc.resolve(read(0.799), deps).served_probability;
    const outside = pc.resolve(read(0.80), deps);
    expect(inside).not.toBeNull();
    expect(outside.served_probability).toBeNull();
    expect(outside.served_probability).not.toBe(0.80);
  });
});

describe('actionability law', () => {
  const odds = -115;
  it('derives EV, Kelly and VALUE from the SERVED probability', () => {
    const r = pc.resolve(read(0.65), deps);
    const d = pc.derivedClaims(r, odds);
    expect(d.available).toBe(true);
    expect(d.computed_from).toBe('served_probability');
    const { evPct } = require('../../src/utils/devig');
    expect(d.ev_pct).toBe(evPct(r.served_probability, odds));
    expect(d.ev_pct).not.toBe(evPct(0.65, odds));      // NOT from raw
  });

  it('withdraws EV, Kelly and VALUE entirely when no probability is certified', () => {
    for (const p of [0.85, 0.95]) {
      const d = pc.derivedClaims(pc.resolve(read(p), deps), odds);
      expect(d.available).toBe(false);
      expect(d.ev_pct).toBeNull();
      expect(d.kelly).toBeNull();
      expect(d.value).toBeNull();
    }
  });

  it('never computes a derived claim from raw behind the scenes', () => {
    const { evPct } = require('../../src/utils/devig');
    const { quarterKelly } = require('../../src/utils/kelly');
    const d = pc.derivedClaims(pc.resolve(read(0.91), deps), odds);
    expect(d.ev_pct).not.toBe(evPct(0.91, odds));
    expect(d.kelly).not.toEqual(quarterKelly(0.91, odds));
    expect(d.kelly).toBeNull();
  });

  it('a VERSION_MISMATCH withdraws actionability too', () => {
    const d = pc.derivedClaims(pc.resolve(read(0.65, { model_version: 'other' }), deps), odds);
    expect(d.available).toBe(false);
  });
});

describe('confidence display', () => {
  it('shows an exact number only when the state is certified', () => {
    const c = pc.confidenceDisplay(pc.resolve(read(0.65), deps));
    expect(c.exact_probability).toBe(iso(0.65));
    expect(c.calibrated).toBe(true);
  });

  it('shows NO exact confidence when uncertified — and never the raw value', () => {
    const c = pc.confidenceDisplay(pc.resolve(read(0.91), deps));
    expect(c.exact_probability).toBeNull();
    expect(c.exact_pct).toBeNull();
    expect(c.calibrated).toBe(false);
    expect(c.label).toBe('Confidence not calibrated');
    expect(JSON.stringify(c)).not.toContain('0.91');
  });
});

describe('the artifact records its own adjudication', () => {
  it('is pinned to the current model era and the isotonic estimator', () => {
    expect(pc.MLB_HITS.model_version).toBe(ERA);
    expect(pc.MLB_HITS.estimator_type).toBe(pc.ESTIMATOR.ISOTONIC);
    expect(pc.MLB_HITS.estimator_version).toBeTruthy();
    expect(pc.MLB_HITS.certification_version).toBeTruthy();
  });

  it('certifies nothing above raw 0.80 — the region where raw is most wrong', () => {
    for (const p of [0.80, 0.85, 0.90, 0.95]) {
      expect(pc.inCertifiedRawBand(pc.MLB_HITS.certified_bands, p)).toBe(false);
    }
  });

  it('holds ONE contract — no other sport or stat is certified', () => {
    expect(Object.keys(pc.CONTRACTS)).toEqual(['mlb:hits']);
  });

  it('the held-out interval it records excludes zero', () => {
    expect(pc.MLB_HITS.evidence.ci95[1]).toBeLessThan(0);
  });
});

describe('the registry already asked the right question', () => {
  it('serves() tests certified bands against the RAW p_win, not the output', () => {
    const r = reg.createRegistry();
    r.deploy('hits', { lodo_pass: true, ci: [-0.006, -0.001], map: { x: [0], y: [0] },
      certified_bands: [[0.50, 0.80]] });
    expect(r.serves('hits', 0.65).serve).toBe(true);
    expect(r.serves('hits', 0.90).serve).toBe(false);
  });

  it('a refusal names the reason and never proposes raw', () => {
    const r = reg.createRegistry();
    r.deploy('hits', { lodo_pass: true, ci: [-0.006, -0.001], map: {}, certified_bands: [[0.50, 0.80]] });
    const out = r.serves('hits', 0.92);
    expect(out.serve).toBe(false);
    expect(JSON.stringify(out)).not.toContain('0.92');
  });
});

describe('probabilityContractService — loads, never fits', () => {
  const registry = require('../../src/services/model/artifactRegistry');

  it('returns the PROMOTED frozen artifact, not a fresh fit', async () => {
    const b = await svc.build(null, { sport: 'mlb', stat: 'hits' });
    expect(b).not.toBeNull();
    expect(b.artifact.artifact_id).toBe(registry.PROMOTED['mlb:hits'].artifact_id);
    expect(b.artifact.servable).toBe(true);
  });

  it('returns null — never a fallback curve — when nothing is promoted', async () => {
    for (const stat of ['rbi', 'total_bases', 'runs']) {
      expect(await svc.build(null, { sport: 'mlb', stat })).toBeNull();
    }
    expect(await svc.build(null, { sport: 'wnba', stat: 'points' })).toBeNull();
  });

  it('needs no database client at all — there is nothing left to read', async () => {
    const b = await svc.build(undefined, { sport: 'mlb', stat: 'hits' });
    expect(b.artifact.artifact_id).toBeTruthy();
  });

  it('two resolutions of the same input are identical, forever', async () => {
    const b1 = await svc.build(null, { sport: 'mlb', stat: 'hits' });
    const b2 = await svc.build(null, { sport: 'mlb', stat: 'hits' });
    for (const p of [0.50, 0.55, 0.601, 0.72, 0.799]) {
      // the read NAMES its stat — the resolver no longer substitutes one
      const a = b1.resolve({ sport: 'mlb', stat: 'hits', model_version: ERA, p_win: p });
      const c = b2.resolve({ sport: 'mlb', stat: 'hits', model_version: ERA, p_win: p });
      expect(a.served_probability).toBe(c.served_probability);
      expect(a.artifact.knot_digest).toBe(c.artifact.knot_digest);
    }
  });
});

describe('artifact identity — the frozen curve that actually ran', () => {
  const registry = require('../../src/services/model/artifactRegistry');
  const a = registry.load('mlb', 'hits');

  it('carries every field needed to find and check it again', () => {
    for (const k of ['artifact_id', 'procedure_version', 'sport', 'stat', 'model_version',
      'fit_as_of', 'training_cutoff', 'fit_n', 'source_digest', 'algorithm', 'algorithm_version',
      'knot_count', 'knot_digest', 'served_curve', 'served_curve_digest', 'certified_bands']) {
      expect(a[k]).toBeDefined();
      expect(a[k]).not.toBeNull();
    }
  });

  it('fit_as_of and training_cutoff are DIFFERENT questions', () => {
    // the eligibility bound, and the newest observation actually admitted
    expect(a.fit_as_of).not.toBe(a.training_cutoff);
    expect(a.training_cutoff < a.fit_as_of).toBe(true);
  });

  it('was fitted on the current era ONLY', () => {
    expect(a.model_version).toBe(ERA);
    expect(a.era_audit.wrong_era_rows).toBe(0);
    expect(Object.keys(a.era_audit.era_counts)).toEqual([ERA]);
  });

  it('withheld nothing from the promoted fit', () => {
    expect(a.withheld_from_fit).toBe(0);
    expect(a.fit_n).toBe(a.era_audit.current_era_rows);
  });

  it('the served curve IS the served function over support, not a sample', () => {
    for (let x = 0.50; x < 0.80 - 1e-9; x += 0.001) {
      const raw = Math.round(x * 1000) / 1000;
      let want = null;
      for (const [from, val] of a.served_curve) { if (raw >= from) want = val; else break; }
      expect(registry.applyCurve(a, raw)).toBe(want);
    }
  });

  it('the curve covers ONLY certified support', () => {
    for (const [from] of a.served_curve) {
      expect(from).toBeGreaterThanOrEqual(0.50);
      expect(from).toBeLessThan(0.80);
    }
    for (const p of [0.499, 0.80, 0.9, 0.99]) expect(registry.applyCurve(a, p)).toBeNull();
  });
});

describe('point in time — a Read can only see settlements before its own day', () => {
  const calSvc = require('../../src/services/model/calibrationService');

  /** Records the filters actually applied, so this tests behaviour not source. */
  function recordingClient(rows) {
    const applied = [];
    const q = {
      select: () => q, eq: (c, v) => { applied.push(['eq', c, v]); return q; },
      is: (c, v) => { applied.push(['is', c, v]); return q; },
      in: (c, v) => { applied.push(['in', c, v]); return q; },
      not: (c, o, v) => { applied.push(['not', c, o, v]); return q; },
      lt: (c, v) => { applied.push(['lt', c, v]); return q; },
      lte: (c, v) => { applied.push(['lte', c, v]); return q; },
      gte: (c, v) => { applied.push(['gte', c, v]); return q; },
      order: () => q, limit: () => q,
      range: async () => ({ data: rows, error: null, count: rows.length }),
      then: (res) => res({ data: rows, error: null }),
    };
    return { applied, client: { from: () => q } };
  }

  it('bounds the training walk STRICTLY BEFORE the cutoff, never at or after it', async () => {
    const { applied, client } = recordingClient([]);
    await calSvc.loadSettledRows(client, { sport: 'mlb', stat: 'hits', before: '2026-09-02' });
    const bound = applied.filter((a) => a[1] === 'game_date');
    expect(bound.length).toBeGreaterThan(0);
    // strictly-less is the whole discipline: `lte` would admit same-day games
    expect(bound.some((a) => a[0] === 'lt' && a[2] === '2026-09-02')).toBe(true);
    expect(bound.some((a) => a[0] === 'lte')).toBe(false);
    expect(bound.some((a) => a[0] === 'gte')).toBe(false);
  });

  it('the artifact names its own evidence horizon', async () => {
    const built = await svc.build(null, { sport: 'mlb', stat: 'hits' });
    expect(built.artifact.fit_as_of).toBeTruthy();
    expect(built.artifact.training_cutoff).toBeTruthy();
    // the bound, and the last date inside it — never the same claim
    expect(built.artifact.training_cutoff < built.artifact.fit_as_of).toBe(true);
  });
});