1---
2title: Check Cheap Conditions Before Async Flags
3impact: HIGH
4impactDescription: avoids unnecessary async work when a synchronous guard already fails
5tags: async, await, feature-flags, short-circuit, conditional
6---
7 
8## Check Cheap Conditions Before Async Flags
9 
10When a branch uses `await` for a flag or remote value and also requires a **cheap synchronous** condition (local props, request metadata, already-loaded state), evaluate the cheap condition **first**. Otherwise you pay for the async call even when the compound condition can never be true.
11 
12This is a specialization of [Defer Await Until Needed](./async-defer-await.md) for `flag && cheapCondition` style checks.
13 
14**Incorrect:**
15 
16```typescript
17const someFlag = await getFlag()
18 
19if (someFlag && someCondition) {
20  // ...
21}
22```
23 
24**Correct:**
25 
26```typescript
27if (someCondition) {
28  const someFlag = await getFlag()
29  if (someFlag) {
30    // ...
31  }
32}
33```
34 
35This matters when `getFlag` hits the network, a feature-flag service, or `React.cache` / DB work: skipping it when `someCondition` is false removes that cost on the cold path.
36 
37Keep the original order if `someCondition` is expensive, depends on the flag, or you must run side effects in a fixed order.
38