import { describe, expect, it } from "vitest";
import { formatStarCount } from "./use-github-stars";

describe("formatStarCount", () => {
  it("renders counts below 1,000 exactly", () => {
    expect(formatStarCount(0)).toBe("0");
    expect(formatStarCount(7)).toBe("7");
    expect(formatStarCount(999)).toBe("999");
  });

  it("formats thousands with one decimal, GitHub-style", () => {
    expect(formatStarCount(37_600)).toBe("37.6k");
    expect(formatStarCount(1_234)).toBe("1.2k");
    expect(formatStarCount(12_300)).toBe("12.3k");
  });

  it("trims a trailing .0 ('1k', not '1.0k')", () => {
    expect(formatStarCount(1_000)).toBe("1k");
    expect(formatStarCount(2_000)).toBe("2k");
  });

  it("rounds to one decimal like the repo header", () => {
    expect(formatStarCount(1_949)).toBe("1.9k");
    expect(formatStarCount(1_990)).toBe("2k");
  });

  it("formats millions with an 'm' suffix", () => {
    expect(formatStarCount(1_200_000)).toBe("1.2m");
    expect(formatStarCount(2_000_000)).toBe("2m");
  });
});