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Format: YYYY-MM-DD-description.md - 2026-01-19-infrastructure-deployment.md - 2026-01-19-backend-api-implementation.md (in progress) Co-Authored-By: Claude Sonnet 4.5 (1M context) <noreply@anthropic.com>
1.7 KiB
1.7 KiB
title, impact, impactDescription, tags
| title | impact | impactDescription | tags |
|---|---|---|---|
| Use toSorted() Instead of sort() for Immutability | MEDIUM-HIGH | prevents mutation bugs in React state | javascript, arrays, immutability, react, state, mutation |
Use toSorted() Instead of sort() for Immutability
.sort() mutates the array in place, which can cause bugs with React state and props. Use .toSorted() to create a new sorted array without mutation.
Incorrect (mutates original array):
function UserList({ users }: { users: User[] }) {
// Mutates the users prop array!
const sorted = useMemo(
() => users.sort((a, b) => a.name.localeCompare(b.name)),
[users]
)
return <div>{sorted.map(renderUser)}</div>
}
Correct (creates new array):
function UserList({ users }: { users: User[] }) {
// Creates new sorted array, original unchanged
const sorted = useMemo(
() => users.toSorted((a, b) => a.name.localeCompare(b.name)),
[users]
)
return <div>{sorted.map(renderUser)}</div>
}
Why this matters in React:
- Props/state mutations break React's immutability model - React expects props and state to be treated as read-only
- Causes stale closure bugs - Mutating arrays inside closures (callbacks, effects) can lead to unexpected behavior
Browser support (fallback for older browsers):
.toSorted() is available in all modern browsers (Chrome 110+, Safari 16+, Firefox 115+, Node.js 20+). For older environments, use spread operator:
// Fallback for older browsers
const sorted = [...items].sort((a, b) => a.value - b.value)
Other immutable array methods:
.toSorted()- immutable sort.toReversed()- immutable reverse.toSpliced()- immutable splice.with()- immutable element replacement