import { describe, expect, it } from 'vitest';
import { ScalarRingBuffer } from './ScalarRingBuffer';

const point = (step: number, value = step) => ({ step, wallTime: step / 10, value });

describe('ScalarRingBuffer', () => {
  it('固定容量覆盖最旧点并保持按 step 排序', () => {
    const buffer = new ScalarRingBuffer(3);
    buffer.appendMany([point(2), point(1), point(3), point(4)]);
    expect(buffer.size).toBe(3);
    expect(buffer.snapshot().map((value) => value.step)).toEqual([1, 3, 4]);
    expect(buffer.latestStep).toBe(4);
  });

  it('按 step 去重更新且忽略非有限数据', () => {
    const buffer = new ScalarRingBuffer(4);
    expect(buffer.append(point(1, 2))).toBe(true);
    expect(buffer.append(point(1, 2))).toBe(false);
    expect(buffer.append(point(1, 3))).toBe(true);
    expect(buffer.append({ step: 2, wallTime: 0, value: Number.NaN })).toBe(false);
    expect(buffer.snapshot()).toEqual([{ step: 1, wallTime: 0.1, value: 3 }]);
  });
});