brackt/app/lib/__tests__/standings-display.test.ts

import { describe, it, expect } from "vitest";
import { buildTiedRankChecker, getDisplayRank } from "../standings-display";

describe("buildTiedRankChecker", () => {
  it("returns false for a rank held by only one team", () => {
    const isTied = buildTiedRankChecker([1, 2, 3]);
    expect(isTied(1)).toBe(false);
    expect(isTied(2)).toBe(false);
    expect(isTied(3)).toBe(false);
  });

  it("returns true for a rank shared by two or more teams", () => {
    const isTied = buildTiedRankChecker([1, 3, 3, 5]);
    expect(isTied(3)).toBe(true);
  });

  it("returns false for a rank not present in the list", () => {
    const isTied = buildTiedRankChecker([1, 2]);
    expect(isTied(99)).toBe(false);
  });

  it("handles all teams tied at rank 1", () => {
    const isTied = buildTiedRankChecker([1, 1, 1]);
    expect(isTied(1)).toBe(true);
  });

  it("handles an empty list without throwing", () => {
    const isTied = buildTiedRankChecker([]);
    expect(isTied(1)).toBe(false);
  });
});

describe("getDisplayRank", () => {
  describe("when the team has a standing", () => {
    it("returns the numeric rank regardless of how many other teams have standings", () => {
      expect(getDisplayRank({ currentRank: 1 }, 5)).toBe(1);
      expect(getDisplayRank({ currentRank: 3 }, 5)).toBe(3);
    });

    it("returns rank 1 when the team is first", () => {
      expect(getDisplayRank({ currentRank: 1 }, 1)).toBe(1);
    });
  });

  describe("when the team has no standing and no teams have been scored yet", () => {
    it("returns T1 — all teams are genuinely tied at zero", () => {
      expect(getDisplayRank(undefined, 0)).toBe("T1");
    });
  });

  describe("when the team has no standing but other teams have been scored", () => {
    it("returns T{n+1} where n is the number of teams with standings", () => {
      // 1 team has a standing → unranked teams are tied for 2nd
      expect(getDisplayRank(undefined, 1)).toBe("T2");

      // 3 teams have standings → unranked teams are tied for 4th
      expect(getDisplayRank(undefined, 3)).toBe("T4");

      // 9 teams have standings → unranked team is tied for 10th
      expect(getDisplayRank(undefined, 9)).toBe("T10");
    });

    it("never shows T1 when any other team has a standing", () => {
      // Would be wrong to show T1 here — that team isn't first
      expect(getDisplayRank(undefined, 1)).not.toBe("T1");
      expect(getDisplayRank(undefined, 5)).not.toBe("T1");
    });
  });
});