import { describe, expect, it } from "vitest";
import { number, roundForDisplay, titleCase } from "./format";

describe("display number formatting", () => {
  it("uses two decimal places for ordinary values", () => {
    expect(number(12.3456)).toBe("12.35");
    expect(roundForDisplay(12.3456)).toBe(12.35);
  });

  it("uses three decimal places for small nonzero values", () => {
    expect(number(0.0964)).toBe("0.096");
    expect(roundForDisplay(0.0964)).toBe(0.096);
  });

  it("does not add insignificant trailing zeroes", () => {
    expect(number(2)).toBe("2");
    expect(number(0)).toBe("0");
  });
});

describe("title case formatting", () => {
  it("capitalizes the first letter of each word without lowercasing source data", () => {
    expect(titleCase("baking powder, double-acting")).toBe("Baking Powder, Double-acting");
    expect(titleCase("USDA choice beef")).toBe("USDA Choice Beef");
  });

  it("preserves punctuation and whitespace-separated numeric tokens", () => {
    expect(titleCase("2% milk")).toBe("2% Milk");
  });
});