Cursor rule

1---
2alwaysApply: false
3---
4 
5## Dependency-Based Parallelization
6 
7For operations with partial dependencies, use `better-all` to maximize parallelism. It automatically starts each task at the earliest possible moment.
8 
9**Incorrect (profile waits for config unnecessarily):**
10 
11```typescript
12const [user, config] = await Promise.all([
13  fetchUser(),
14  fetchConfig()
15])
16const profile = await fetchProfile(user.id)
17```
18 
19**Correct (config and profile run in parallel):**
20 
21```typescript
22import { all } from 'better-all'
23 
24const { user, config, profile } = await all({
25  async user() { return fetchUser() },
26  async config() { return fetchConfig() },
27  async profile() {
28    return fetchProfile((await this.$.user).id)
29  }
30})
31```
32 
33**Alternative without extra dependencies:**
34 
35We can also create all the promises first, and do `Promise.all()` at the end.
36 
37```typescript
38const userPromise = fetchUser()
39const profilePromise = userPromise.then(user => fetchProfile(user.id))
40 
41const [user, config, profile] = await Promise.all([
42  userPromise,
43  fetchConfig(),
44  profilePromise
45])
46```
47 
48Reference: [https://github.com/shuding/better-all](https://github.com/shuding/better-all)
49