factory/lib/projects-meta-mcp/tests/lib/cache.test.ts

import { describe, it, expect } from 'vitest';
import { mkdtemp, readFile, stat, writeFile } from 'node:fs/promises';
import { tmpdir } from 'node:os';
import { join } from 'node:path';
import {
  writeCache,
  readCache,
  detectCacheInvalidation,
  CACHE_SCHEMA_VERSION,
  type CacheFile,
} from '../../src/lib/cache.js';

const sample: CacheFile = {
  schemaVersion: 3,
  synced_at: '2026-04-29T12:00:00.000Z',
  synced_from: 'https://git.kzntsv.site',
  machine: 'test',
  projects: [],
  errors: [],
};

describe('cache', () => {
  it('writes JSON atomically and reads it back', async () => {
    const dir = await mkdtemp(join(tmpdir(), 'cache-'));
    const file = join(dir, 'tasks.json');
    await writeCache(file, sample);
    const back = await readCache(file);
    expect(back).toEqual(sample);
  });

  it('does not leave .tmp file on success', async () => {
    const dir = await mkdtemp(join(tmpdir(), 'cache-'));
    const file = join(dir, 'tasks.json');
    await writeCache(file, sample);
    await expect(stat(file + '.tmp')).rejects.toThrow();
  });

  it('returns null when cache file missing', async () => {
    const dir = await mkdtemp(join(tmpdir(), 'cache-'));
    const back = await readCache(join(dir, 'missing.json'));
    expect(back).toBeNull();
  });

  it('creates parent directory if missing', async () => {
    const dir = await mkdtemp(join(tmpdir(), 'cache-'));
    const file = join(dir, 'nested', 'deep', 'tasks.json');
    await writeCache(file, sample);
    const txt = await readFile(file, 'utf8');
    expect(JSON.parse(txt)).toEqual(sample);
  });

  it('exports CACHE_SCHEMA_VERSION = 3', () => {
    expect(CACHE_SCHEMA_VERSION).toBe(3);
  });

  it('returns null on legacy cache without schemaVersion', async () => {
    const dir = await mkdtemp(join(tmpdir(), 'cache-'));
    const file = join(dir, 'tasks.json');
    const legacy = {
      synced_at: '2026-04-29T12:00:00.000Z',
      synced_from: 'https://g',
      machine: 'test',
      projects: [{ name: 'bare-name', default_branch: 'main', fetched_at: '2026-04-29T12:00:00Z', active_tasks: [], all_tasks_count: 0, raw: '' }],
      errors: [],
    };
    await writeFile(file, JSON.stringify(legacy), 'utf8');
    const back = await readCache(file);
    expect(back).toBeNull();
  });

  it('returns null on schemaVersion mismatch', async () => {
    const dir = await mkdtemp(join(tmpdir(), 'cache-'));
    const file = join(dir, 'tasks.json');
    const v1 = { ...sample, schemaVersion: 1 };
    await writeFile(file, JSON.stringify(v1), 'utf8');
    const back = await readCache(file);
    expect(back).toBeNull();
  });

  it('returns null on v2 cache (pre-agenda-rename, name === "_meta" entries are stale)', async () => {
    const dir = await mkdtemp(join(tmpdir(), 'cache-'));
    const file = join(dir, 'tasks.json');
    const v2 = { ...sample, schemaVersion: 2 };
    await writeFile(file, JSON.stringify(v2), 'utf8');
    const back = await readCache(file);
    expect(back).toBeNull();
  });
});

describe('detectCacheInvalidation', () => {
  it('returns invalidated:false when file missing', async () => {
    const dir = await mkdtemp(join(tmpdir(), 'cache-'));
    const r = await detectCacheInvalidation(join(dir, 'missing.json'));
    expect(r).toEqual({ invalidated: false, oldVersion: null });
  });

  it('returns invalidated:true, oldVersion:null on legacy (no field)', async () => {
    const dir = await mkdtemp(join(tmpdir(), 'cache-'));
    const file = join(dir, 'tasks.json');
    await writeFile(file, JSON.stringify({ synced_at: 't', projects: [] }), 'utf8');
    const r = await detectCacheInvalidation(file);
    expect(r).toEqual({ invalidated: true, oldVersion: null });
  });

  it('returns invalidated:true, oldVersion:1 on v1 cache', async () => {
    const dir = await mkdtemp(join(tmpdir(), 'cache-'));
    const file = join(dir, 'tasks.json');
    await writeFile(file, JSON.stringify({ schemaVersion: 1, projects: [] }), 'utf8');
    const r = await detectCacheInvalidation(file);
    expect(r).toEqual({ invalidated: true, oldVersion: 1 });
  });

  it('returns invalidated:true, oldVersion:2 on v2 cache (pre-agenda-rename)', async () => {
    const dir = await mkdtemp(join(tmpdir(), 'cache-'));
    const file = join(dir, 'tasks.json');
    await writeFile(file, JSON.stringify({ schemaVersion: 2, projects: [] }), 'utf8');
    const r = await detectCacheInvalidation(file);
    expect(r).toEqual({ invalidated: true, oldVersion: 2 });
  });

  it('returns invalidated:false, oldVersion:3 on current cache', async () => {
    const dir = await mkdtemp(join(tmpdir(), 'cache-'));
    const file = join(dir, 'tasks.json');
    await writeCache(file, sample);
    const r = await detectCacheInvalidation(file);
    expect(r).toEqual({ invalidated: false, oldVersion: 3 });
  });
});