aether-shards/test/utils/SimplexNoise.test.js

import { expect } from "@esm-bundle/chai";
import { SimplexNoise } from "../../src/utils/SimplexNoise.js";

describe("Utility: Custom Simplex Noise", () => {
  it("CoA 1: Should be deterministic with the same seed", () => {
    const gen1 = new SimplexNoise(12345);
    const val1 = gen1.noise2D(0.5, 0.5);

    const gen2 = new SimplexNoise(12345);
    const val2 = gen2.noise2D(0.5, 0.5);

    expect(val1).to.equal(val2);
  });

  it("CoA 2: Should produce different values for different seeds", () => {
    const gen1 = new SimplexNoise(12345);
    const val1 = gen1.noise2D(0.5, 0.5);

    const gen2 = new SimplexNoise(99999);
    const val2 = gen2.noise2D(0.5, 0.5);

    expect(val1).to.not.equal(val2);
  });

  it("CoA 3: Should output values within expected range (approx -1 to 1)", () => {
    const gen = new SimplexNoise(123);
    const val = gen.noise2D(10, 10);

    expect(val).to.be.within(-1.2, 1.2); // Simplex can technically slightly exceed 1.0
  });
});