rg-stats/src/algorithms/maimai-rate.test.ts

A library for calculating various rhythm game stats.

import t from "tap";
import { isAprx } from "../test-utils/approx";
import { TestCase } from "../test-utils/test-case";
import { ThrowsToSnapshot } from "../test-utils/throw-snapshot";
import { calculate } from "./maimai-rate";

t.test("maimai Rate Tests", (t) => {
	function MakeTestCase(
		score: number,
		maxScore: number,
		level: number,
		expectedRate: number
	): TestCase {
		return (t) =>
			isAprx(
				t,
				calculate(score, maxScore, level),
				expectedRate,
				`A score of ${score}/${maxScore} on a chart of level ${level} should be worth ${expectedRate} rate.`
			);
	}

	const testCases = [
		// Assertions plucked from a random user account
		MakeTestCase(100.89, 101.58, 11.8, 14.36),
		MakeTestCase(100.8, 101.18, 12.0, 14.68),
		MakeTestCase(100.23, 100.72, 11.7, 14.02),
		MakeTestCase(99.36, 100.42, 11.0, 12.27),
		MakeTestCase(98.04, 101.21, 10.2, 10.8),
		MakeTestCase(97.62, 100.56, 10.1, 10.47),
		MakeTestCase(96.79, 101.19, 10.8, 9.76),
		MakeTestCase(95.08, 100.91, 10.5, 9.18),
		MakeTestCase(94.16, 100.83, 12.5, 11.04),
		MakeTestCase(93.05, 100.31, 11.5, 9.88),
		MakeTestCase(92.5, 100.53, 13.6, 11.91),
		MakeTestCase(91.62, 100.5, 11.7, 9.9),

		// General boundary checks
		MakeTestCase(100.68, 100.68, 14, 19),
		MakeTestCase(100, 100.79, 13.9, 17.8),

		// SS tests
		MakeTestCase(99, 100.71, 12.9, 14.8),
		MakeTestCase(99, 100.54, 8, 9.5),
		MakeTestCase(99, 100.54, 7, 9),

		// S tests
		MakeTestCase(97, 100.36, 11.5, 11.5),
		MakeTestCase(97, 100.54, 8, 8),
		MakeTestCase(97, 100.54, 7, 7.5),

		MakeTestCase(94, 100.3, 10, 8.5),
		MakeTestCase(90, 100.3, 12.5, 10.5),
		MakeTestCase(80, 100.5, 13, 10),
		MakeTestCase(60, 100.59, 12.7, 5.08),
		MakeTestCase(40, 100.54, 9, 1.8),
		MakeTestCase(20, 100.72, 13.6, 1.36),
		MakeTestCase(13, 100.61, 11.7, 0.35),
		MakeTestCase(9, 100.26, 10.5, 0),

		MakeTestCase(100, 100, 13.9, 18.8),
		MakeTestCase(96.99, 100, 8.9, 7.95),

		// Levels beyond 15 should be extrapolated from lv14 and 15 values
		MakeTestCase(100.9, 100.9, 15.4, 21.8),
	];

	for (const testCase of testCases) {
		testCase(t);
	}

	t.end();
});

t.test("maimai Rate Validation Tests", (t) => {
	ThrowsToSnapshot(
		t,
		() => calculate(100, 104.1, 10),
		"Should throw if max score is greater than 104%."
	);
	ThrowsToSnapshot(
		t,
		() => calculate(101.5, 100.68, 10),
		"Should throw if score is greater than max score."
	);
	ThrowsToSnapshot(t, () => calculate(-1, 100.68, 10), "Should throw if score is negative.");
	ThrowsToSnapshot(t, () => calculate(99.5, 100.68, -1), "Should throw if level is negative.");

	t.end();
});