brackt/app/routes/__tests__/admin.sports-seasons.$id.expected-values.test.ts

import { describe, expect, it, vi } from "vitest";

/**
 * The Expected Values admin page renders EV from the stored probability columns.
 *
 * It used to carry its own hardcoded scoring table (100/70/45/45/20/20/20/20), which
 * flattened positions 5–8 to 20 points each. For a standard single-elimination bracket
 * that was invisible — all four quarterfinal losers share one tier worth
 * avg(25,25,15,15) = 20 anyway — but for the templates that split 5–8 into two tiers
 * (llws_20, afl_10) it reported a team locked into 5th–6th and a team locked into
 * 7th–8th as the same 20 points. These pin it to the shared DEFAULT_SCORING_RULES.
 */

vi.mock("../admin.sports-seasons.$id.expected-values.server", () => ({
  loader: vi.fn(),
}));

import { evFromProbs } from "../admin.sports-seasons.$id.expected-values";

const ZERO = {
  probFirst: "0", probSecond: "0", probThird: "0", probFourth: "0",
  probFifth: "0", probSixth: "0", probSeventh: "0", probEighth: "0",
};

describe("evFromProbs", () => {
  it("gives a team locked into the 5th–6th tier 25 points, not 20", () => {
    expect(evFromProbs({ ...ZERO, probFifth: "0.5", probSixth: "0.5" })).toBe(25);
  });

  it("gives a team locked into the 7th–8th tier 15 points, not 20", () => {
    expect(evFromProbs({ ...ZERO, probSeventh: "0.5", probEighth: "0.5" })).toBe(15);
  });

  it("still gives a single 5th–8th tier (4 QF losers) 20 points", () => {
    const ev = evFromProbs({
      ...ZERO,
      probFifth: "0.25", probSixth: "0.25", probSeventh: "0.25", probEighth: "0.25",
    });
    expect(ev).toBe(20);
  });

  it("keeps 3rd and 4th distinct rather than a flat 45 each", () => {
    expect(evFromProbs({ ...ZERO, probThird: "1" })).toBe(50);
    expect(evFromProbs({ ...ZERO, probFourth: "1" })).toBe(40);
  });

  it("preserves the 340 total-EV invariant across a full set of unit columns", () => {
    const perPosition = [
      evFromProbs({ ...ZERO, probFirst: "1" }),
      evFromProbs({ ...ZERO, probSecond: "1" }),
      evFromProbs({ ...ZERO, probThird: "1" }),
      evFromProbs({ ...ZERO, probFourth: "1" }),
      evFromProbs({ ...ZERO, probFifth: "1" }),
      evFromProbs({ ...ZERO, probSixth: "1" }),
      evFromProbs({ ...ZERO, probSeventh: "1" }),
      evFromProbs({ ...ZERO, probEighth: "1" }),
    ];
    expect(perPosition.reduce((sum, ev) => sum + ev, 0)).toBe(340);
  });

  it("returns 0 for a participant with no probability mass", () => {
    expect(evFromProbs(ZERO)).toBe(0);
  });
});