devperf/backend/tests/unit/roi-engine.test.ts

/**
 * ROI 引擎纯函数单元测试。
 * 仅测不依赖 DB 的逻辑;聚合/查询走集成测试。
 */
import { describe, it, expect } from 'bun:test';
import { evaluateConfidence } from '../../src/services/roi/confidence-evaluator';
import { bepFromTotals } from '../../src/services/roi/bep-calculator';

describe('confidence-evaluator', () => {
  it('returns low when no events at all', () => {
    expect(evaluateConfidence([], [])).toBe('low');
  });

  it('returns low when only cost, no revenue', () => {
    expect(evaluateConfidence([{ dataSource: 'manual' }], [])).toBe('low');
  });

  it('returns low when all cost is auto-estimated', () => {
    const costs = [
      { dataSource: 'auto_commits' },
      { dataSource: 'auto_tasks' },
    ];
    const revenues = [{ dataSource: 'manual' }];
    expect(evaluateConfidence(costs, revenues)).toBe('low');
  });

  it('returns high when 80%+ cost is plane_actual/manual + revenue exists', () => {
    const costs = [
      { dataSource: 'plane_actual' },
      { dataSource: 'plane_actual' },
      { dataSource: 'manual' },
      { dataSource: 'manual' },
      { dataSource: 'auto_commits' },  // 1/5 = 20% 自动,刚好满足 80%+ 高质量
    ];
    const revenues = [{ dataSource: 'api_pulled' }];
    expect(evaluateConfidence(costs, revenues)).toBe('high');
  });

  it('returns medium when high-quality cost ratio is between 1% and 80%', () => {
    const costs = [
      { dataSource: 'plane_actual' },
      { dataSource: 'auto_commits' },
      { dataSource: 'auto_commits' },
    ];
    const revenues = [{ dataSource: 'manual' }];
    // 1/3 = 33% 高质量,落在 medium 区间
    expect(evaluateConfidence(costs, revenues)).toBe('medium');
  });

  it('returns high when all cost manual', () => {
    const costs = [{ dataSource: 'manual' }, { dataSource: 'manual' }];
    const revenues = [{ dataSource: 'manual' }];
    expect(evaluateConfidence(costs, revenues)).toBe('high');
  });
});

describe('bepFromTotals', () => {
  it('returns 0 when already broken even (revenue >= cost)', () => {
    expect(bepFromTotals(100000, 100000, 0, 0)).toBe(0);
    expect(bepFromTotals(100000, 150000, 0, 0)).toBe(0);
  });

  it('returns null when recent net income is non-positive', () => {
    // 累计亏 5w,近 30 天净产出为 0
    expect(bepFromTotals(100000, 50000, 30000, 30000)).toBe(null);
    // 近 30 天还在亏
    expect(bepFromTotals(100000, 50000, 30000, 20000)).toBe(null);
  });

  it('returns positive days when on track to break even', () => {
    // 总投入 100w,总产出 80w => 缺口 20w
    // 近 30 天:成本 3w,收入 6w => 日均净 1000 元
    // 预计天数 = 200000 / 1000 = 200 天
    expect(bepFromTotals(1_000_000, 800_000, 30_000, 60_000)).toBe(200);
  });

  it('rounds up partial days', () => {
    // 缺口 1000,日均净 300 => 3.33 天向上取整 = 4
    expect(bepFromTotals(2000, 1000, 0, 9000)).toBe(4);  // daily = 9000/30 = 300
  });

  it('respects custom windowDays', () => {
    // 缺口 1000,近 10 天净 1000 => 日均 100 => 10 天回本
    expect(bepFromTotals(2000, 1000, 0, 1000, 10)).toBe(10);
  });
});