SuperCharge Claude Code v1.0.0 - Complete Customization Package

Features:
- 30+ Custom Skills (cognitive, development, UI/UX, autonomous agents)
- RalphLoop autonomous agent integration
- Multi-AI consultation (Qwen)
- Agent management system with sync capabilities
- Custom hooks for session management
- MCP servers integration
- Plugin marketplace setup
- Comprehensive installation script

Components:
- Skills: always-use-superpowers, ralph, brainstorming, ui-ux-pro-max, etc.
- Agents: 100+ agents across engineering, marketing, product, etc.
- Hooks: session-start-superpowers, qwen-consult, ralph-auto-trigger
- Commands: /brainstorm, /write-plan, /execute-plan
- MCP Servers: zai-mcp-server, web-search-prime, web-reader, zread
- Binaries: ralphloop wrapper

Installation: ./supercharge.sh
This commit is contained in:
uroma
2026-01-22 15:35:55 +00:00
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No,Category,Issue,Keywords,Platform,Description,Do,Don't,Code Example Good,Code Example Bad,Severity
1,Async Waterfall,Defer Await,async await defer branch,React/Next.js,Move await into branches where actually used to avoid blocking unused code paths,Move await operations into branches where they're needed,Await at top of function blocking all branches,"if (skip) return { skipped: true }; const data = await fetch()","const data = await fetch(); if (skip) return { skipped: true }",Critical
2,Async Waterfall,Promise.all Parallel,promise all parallel concurrent,React/Next.js,Execute independent async operations concurrently using Promise.all(),Use Promise.all() for independent operations,Sequential await for independent operations,"const [user, posts] = await Promise.all([fetchUser(), fetchPosts()])","const user = await fetchUser(); const posts = await fetchPosts()",Critical
3,Async Waterfall,Dependency Parallelization,better-all dependency parallel,React/Next.js,Use better-all for operations with partial dependencies to maximize parallelism,Use better-all to start each task at earliest possible moment,Wait for unrelated data before starting dependent fetch,"await all({ user() {}, config() {}, profile() { return fetch((await this.$.user).id) } })","const [user, config] = await Promise.all([...]); const profile = await fetchProfile(user.id)",Critical
4,Async Waterfall,API Route Optimization,api route waterfall promise,React/Next.js,In API routes start independent operations immediately even if not awaited yet,Start promises early and await late,Sequential awaits in API handlers,"const sessionP = auth(); const configP = fetchConfig(); const session = await sessionP","const session = await auth(); const config = await fetchConfig()",Critical
5,Async Waterfall,Suspense Boundaries,suspense streaming boundary,React/Next.js,Use Suspense to show wrapper UI faster while data loads,Wrap async components in Suspense boundaries,Await data blocking entire page render,"<Suspense fallback={<Skeleton />}><DataDisplay /></Suspense>","const data = await fetchData(); return <DataDisplay data={data} />",High
6,Bundle Size,Barrel Imports,barrel import direct path,React/Next.js,Import directly from source files instead of barrel files to avoid loading unused modules,Import directly from source path,Import from barrel/index files,"import Check from 'lucide-react/dist/esm/icons/check'","import { Check } from 'lucide-react'",Critical
7,Bundle Size,Dynamic Imports,dynamic import lazy next,React/Next.js,Use next/dynamic to lazy-load large components not needed on initial render,Use dynamic() for heavy components,Import heavy components at top level,"const Monaco = dynamic(() => import('./monaco'), { ssr: false })","import { MonacoEditor } from './monaco-editor'",Critical
8,Bundle Size,Defer Third Party,analytics defer third-party,React/Next.js,Load analytics and logging after hydration since they don't block interaction,Load non-critical scripts after hydration,Include analytics in main bundle,"const Analytics = dynamic(() => import('@vercel/analytics'), { ssr: false })","import { Analytics } from '@vercel/analytics/react'",Medium
9,Bundle Size,Conditional Loading,conditional module lazy,React/Next.js,Load large data or modules only when a feature is activated,Dynamic import when feature enabled,Import large modules unconditionally,"useEffect(() => { if (enabled) import('./heavy.js') }, [enabled])","import { heavyData } from './heavy.js'",High
10,Bundle Size,Preload Intent,preload hover focus intent,React/Next.js,Preload heavy bundles on hover/focus before they're needed,Preload on user intent signals,Load only on click,"onMouseEnter={() => import('./editor')}","onClick={() => import('./editor')}",Medium
11,Server,React.cache Dedup,react cache deduplicate request,React/Next.js,Use React.cache() for server-side request deduplication within single request,Wrap data fetchers with cache(),Fetch same data multiple times in tree,"export const getUser = cache(async () => await db.user.find())","export async function getUser() { return await db.user.find() }",Medium
12,Server,LRU Cache Cross-Request,lru cache cross request,React/Next.js,Use LRU cache for data shared across sequential requests,Use LRU for cross-request caching,Refetch same data on every request,"const cache = new LRUCache({ max: 1000, ttl: 5*60*1000 })","Always fetch from database",High
13,Server,Minimize Serialization,serialization rsc boundary,React/Next.js,Only pass fields that client actually uses across RSC boundaries,Pass only needed fields to client components,Pass entire objects to client,"<Profile name={user.name} />","<Profile user={user} /> // 50 fields serialized",High
14,Server,Parallel Fetching,parallel fetch component composition,React/Next.js,Restructure components to parallelize data fetching in RSC,Use component composition for parallel fetches,Sequential fetches in parent component,"<Header /><Sidebar /> // both fetch in parallel","const header = await fetchHeader(); return <><div>{header}</div><Sidebar /></>",Critical
15,Server,After Non-blocking,after non-blocking logging,React/Next.js,Use Next.js after() to schedule work after response is sent,Use after() for logging/analytics,Block response for non-critical operations,"after(async () => { await logAction() }); return Response.json(data)","await logAction(); return Response.json(data)",Medium
16,Client,SWR Deduplication,swr dedup cache revalidate,React/Next.js,Use SWR for automatic request deduplication and caching,Use useSWR for client data fetching,Manual fetch in useEffect,"const { data } = useSWR('/api/users', fetcher)","useEffect(() => { fetch('/api/users').then(setUsers) }, [])",Medium-High
17,Client,Event Listener Dedup,event listener deduplicate global,React/Next.js,Share global event listeners across component instances,Use useSWRSubscription for shared listeners,Register listener per component instance,"useSWRSubscription('global-keydown', () => { window.addEventListener... })","useEffect(() => { window.addEventListener('keydown', handler) }, [])",Low
18,Rerender,Defer State Reads,state read callback subscription,React/Next.js,Don't subscribe to state only used in callbacks,Read state on-demand in callbacks,Subscribe to state used only in handlers,"const handleClick = () => { const params = new URLSearchParams(location.search) }","const params = useSearchParams(); const handleClick = () => { params.get('ref') }",Medium
19,Rerender,Memoized Components,memo extract expensive,React/Next.js,Extract expensive work into memoized components for early returns,Extract to memo() components,Compute expensive values before early return,"const UserAvatar = memo(({ user }) => ...); if (loading) return <Skeleton />","const avatar = useMemo(() => compute(user)); if (loading) return <Skeleton />",Medium
20,Rerender,Narrow Dependencies,effect dependency primitive,React/Next.js,Specify primitive dependencies instead of objects in effects,Use primitive values in dependency arrays,Use object references as dependencies,"useEffect(() => { console.log(user.id) }, [user.id])","useEffect(() => { console.log(user.id) }, [user])",Low
21,Rerender,Derived State,derived boolean subscription,React/Next.js,Subscribe to derived booleans instead of continuous values,Use derived boolean state,Subscribe to continuous values,"const isMobile = useMediaQuery('(max-width: 767px)')","const width = useWindowWidth(); const isMobile = width < 768",Medium
22,Rerender,Functional setState,functional setstate callback,React/Next.js,Use functional setState updates for stable callbacks and no stale closures,Use functional form: setState(curr => ...),Reference state directly in setState,"setItems(curr => [...curr, newItem])","setItems([...items, newItem]) // items in deps",Medium
23,Rerender,Lazy State Init,usestate lazy initialization,React/Next.js,Pass function to useState for expensive initial values,Use function form for expensive init,Compute expensive value directly,"useState(() => buildSearchIndex(items))","useState(buildSearchIndex(items)) // runs every render",Medium
24,Rerender,Transitions,starttransition non-urgent,React/Next.js,Mark frequent non-urgent state updates as transitions,Use startTransition for non-urgent updates,Block UI on every state change,"startTransition(() => setScrollY(window.scrollY))","setScrollY(window.scrollY) // blocks on every scroll",Medium
25,Rendering,SVG Animation Wrapper,svg animation wrapper div,React/Next.js,Wrap SVG in div and animate wrapper for hardware acceleration,Animate div wrapper around SVG,Animate SVG element directly,"<div class='animate-spin'><svg>...</svg></div>","<svg class='animate-spin'>...</svg>",Low
26,Rendering,Content Visibility,content-visibility auto,React/Next.js,Apply content-visibility: auto to defer off-screen rendering,Use content-visibility for long lists,Render all list items immediately,".item { content-visibility: auto; contain-intrinsic-size: 0 80px }","Render 1000 items without optimization",High
27,Rendering,Hoist Static JSX,hoist static jsx element,React/Next.js,Extract static JSX outside components to avoid re-creation,Hoist static elements to module scope,Create static elements inside components,"const skeleton = <div class='animate-pulse' />; function C() { return skeleton }","function C() { return <div class='animate-pulse' /> }",Low
28,Rendering,Hydration No Flicker,hydration mismatch flicker,React/Next.js,Use inline script to set client-only data before hydration,Inject sync script for client-only values,Use useEffect causing flash,"<script dangerouslySetInnerHTML={{ __html: 'el.className = localStorage.theme' }} />","useEffect(() => setTheme(localStorage.theme), []) // flickers",Medium
29,Rendering,Conditional Render,conditional render ternary,React/Next.js,Use ternary instead of && when condition can be 0 or NaN,Use explicit ternary for conditionals,Use && with potentially falsy numbers,"{count > 0 ? <Badge>{count}</Badge> : null}","{count && <Badge>{count}</Badge>} // renders '0'",Low
30,Rendering,Activity Component,activity show hide preserve,React/Next.js,Use Activity component to preserve state/DOM for toggled components,Use Activity for expensive toggle components,Unmount/remount on visibility toggle,"<Activity mode={isOpen ? 'visible' : 'hidden'}><Menu /></Activity>","{isOpen && <Menu />} // loses state",Medium
31,JS Perf,Batch DOM CSS,batch dom css reflow,React/Next.js,Group CSS changes via classes or cssText to minimize reflows,Use class toggle or cssText,Change styles one property at a time,"element.classList.add('highlighted')","el.style.width='100px'; el.style.height='200px'",Medium
32,JS Perf,Index Map Lookup,map index lookup find,React/Next.js,Build Map for repeated lookups instead of multiple .find() calls,Build index Map for O(1) lookups,Use .find() in loops,"const byId = new Map(users.map(u => [u.id, u])); byId.get(id)","users.find(u => u.id === order.userId) // O(n) each time",Low-Medium
33,JS Perf,Cache Property Access,cache property loop,React/Next.js,Cache object property lookups in hot paths,Cache values before loops,Access nested properties in loops,"const val = obj.config.settings.value; for (...) process(val)","for (...) process(obj.config.settings.value)",Low-Medium
34,JS Perf,Cache Function Results,memoize cache function,React/Next.js,Use module-level Map to cache repeated function results,Use Map cache for repeated calls,Recompute same values repeatedly,"const cache = new Map(); if (cache.has(x)) return cache.get(x)","slugify(name) // called 100 times same input",Medium
35,JS Perf,Cache Storage API,localstorage cache read,React/Next.js,Cache localStorage/sessionStorage reads in memory,Cache storage reads in Map,Read storage on every call,"if (!cache.has(key)) cache.set(key, localStorage.getItem(key))","localStorage.getItem('theme') // every call",Low-Medium
36,JS Perf,Combine Iterations,combine filter map loop,React/Next.js,Combine multiple filter/map into single loop,Single loop for multiple categorizations,Chain multiple filter() calls,"for (u of users) { if (u.isAdmin) admins.push(u); if (u.isTester) testers.push(u) }","users.filter(admin); users.filter(tester); users.filter(inactive)",Low-Medium
37,JS Perf,Length Check First,length check array compare,React/Next.js,Check array lengths before expensive comparisons,Early return if lengths differ,Always run expensive comparison,"if (a.length !== b.length) return true; // then compare","a.sort().join() !== b.sort().join() // even when lengths differ",Medium-High
38,JS Perf,Early Return,early return exit function,React/Next.js,Return early when result is determined to skip processing,Return immediately on first error,Process all items then check errors,"for (u of users) { if (!u.email) return { error: 'Email required' } }","let hasError; for (...) { if (!email) hasError=true }; if (hasError)...",Low-Medium
39,JS Perf,Hoist RegExp,regexp hoist module,React/Next.js,Don't create RegExp inside render - hoist or memoize,Hoist RegExp to module scope,Create RegExp every render,"const EMAIL_RE = /^[^@]+@[^@]+$/; function validate() { EMAIL_RE.test(x) }","function C() { const re = new RegExp(pattern); re.test(x) }",Low-Medium
40,JS Perf,Loop Min Max,loop min max sort,React/Next.js,Use loop for min/max instead of sort - O(n) vs O(n log n),Single pass loop for min/max,Sort array to find min/max,"let max = arr[0]; for (x of arr) if (x > max) max = x","arr.sort((a,b) => b-a)[0] // O(n log n)",Low
41,JS Perf,Set Map Lookups,set map includes has,React/Next.js,Use Set/Map for O(1) lookups instead of array.includes(),Convert to Set for membership checks,Use .includes() for repeated checks,"const allowed = new Set(['a','b']); allowed.has(id)","const allowed = ['a','b']; allowed.includes(id)",Low-Medium
42,JS Perf,toSorted Immutable,tosorted sort immutable,React/Next.js,Use toSorted() instead of sort() to avoid mutating arrays,Use toSorted() for immutability,Mutate arrays with sort(),"users.toSorted((a,b) => a.name.localeCompare(b.name))","users.sort((a,b) => a.name.localeCompare(b.name)) // mutates",Medium-High
43,Advanced,Event Handler Refs,useeffectevent ref handler,React/Next.js,Store callbacks in refs for stable effect subscriptions,Use useEffectEvent for stable handlers,Re-subscribe on every callback change,"const onEvent = useEffectEvent(handler); useEffect(() => { listen(onEvent) }, [])","useEffect(() => { listen(handler) }, [handler]) // re-subscribes",Low
44,Advanced,useLatest Hook,uselatest ref callback,React/Next.js,Access latest values in callbacks without adding to dependency arrays,Use useLatest for fresh values in stable callbacks,Add callback to effect dependencies,"const cbRef = useLatest(cb); useEffect(() => { setTimeout(() => cbRef.current()) }, [])","useEffect(() => { setTimeout(() => cb()) }, [cb]) // re-runs",Low
1 No Category Issue Keywords Platform Description Do Don't Code Example Good Code Example Bad Severity
2 1 Async Waterfall Defer Await async await defer branch React/Next.js Move await into branches where actually used to avoid blocking unused code paths Move await operations into branches where they're needed Await at top of function blocking all branches if (skip) return { skipped: true }; const data = await fetch() const data = await fetch(); if (skip) return { skipped: true } Critical
3 2 Async Waterfall Promise.all Parallel promise all parallel concurrent React/Next.js Execute independent async operations concurrently using Promise.all() Use Promise.all() for independent operations Sequential await for independent operations const [user, posts] = await Promise.all([fetchUser(), fetchPosts()]) const user = await fetchUser(); const posts = await fetchPosts() Critical
4 3 Async Waterfall Dependency Parallelization better-all dependency parallel React/Next.js Use better-all for operations with partial dependencies to maximize parallelism Use better-all to start each task at earliest possible moment Wait for unrelated data before starting dependent fetch await all({ user() {}, config() {}, profile() { return fetch((await this.$.user).id) } }) const [user, config] = await Promise.all([...]); const profile = await fetchProfile(user.id) Critical
5 4 Async Waterfall API Route Optimization api route waterfall promise React/Next.js In API routes start independent operations immediately even if not awaited yet Start promises early and await late Sequential awaits in API handlers const sessionP = auth(); const configP = fetchConfig(); const session = await sessionP const session = await auth(); const config = await fetchConfig() Critical
6 5 Async Waterfall Suspense Boundaries suspense streaming boundary React/Next.js Use Suspense to show wrapper UI faster while data loads Wrap async components in Suspense boundaries Await data blocking entire page render <Suspense fallback={<Skeleton />}><DataDisplay /></Suspense> const data = await fetchData(); return <DataDisplay data={data} /> High
7 6 Bundle Size Barrel Imports barrel import direct path React/Next.js Import directly from source files instead of barrel files to avoid loading unused modules Import directly from source path Import from barrel/index files import Check from 'lucide-react/dist/esm/icons/check' import { Check } from 'lucide-react' Critical
8 7 Bundle Size Dynamic Imports dynamic import lazy next React/Next.js Use next/dynamic to lazy-load large components not needed on initial render Use dynamic() for heavy components Import heavy components at top level const Monaco = dynamic(() => import('./monaco'), { ssr: false }) import { MonacoEditor } from './monaco-editor' Critical
9 8 Bundle Size Defer Third Party analytics defer third-party React/Next.js Load analytics and logging after hydration since they don't block interaction Load non-critical scripts after hydration Include analytics in main bundle const Analytics = dynamic(() => import('@vercel/analytics'), { ssr: false }) import { Analytics } from '@vercel/analytics/react' Medium
10 9 Bundle Size Conditional Loading conditional module lazy React/Next.js Load large data or modules only when a feature is activated Dynamic import when feature enabled Import large modules unconditionally useEffect(() => { if (enabled) import('./heavy.js') }, [enabled]) import { heavyData } from './heavy.js' High
11 10 Bundle Size Preload Intent preload hover focus intent React/Next.js Preload heavy bundles on hover/focus before they're needed Preload on user intent signals Load only on click onMouseEnter={() => import('./editor')} onClick={() => import('./editor')} Medium
12 11 Server React.cache Dedup react cache deduplicate request React/Next.js Use React.cache() for server-side request deduplication within single request Wrap data fetchers with cache() Fetch same data multiple times in tree export const getUser = cache(async () => await db.user.find()) export async function getUser() { return await db.user.find() } Medium
13 12 Server LRU Cache Cross-Request lru cache cross request React/Next.js Use LRU cache for data shared across sequential requests Use LRU for cross-request caching Refetch same data on every request const cache = new LRUCache({ max: 1000, ttl: 5*60*1000 }) Always fetch from database High
14 13 Server Minimize Serialization serialization rsc boundary React/Next.js Only pass fields that client actually uses across RSC boundaries Pass only needed fields to client components Pass entire objects to client <Profile name={user.name} /> <Profile user={user} /> // 50 fields serialized High
15 14 Server Parallel Fetching parallel fetch component composition React/Next.js Restructure components to parallelize data fetching in RSC Use component composition for parallel fetches Sequential fetches in parent component <Header /><Sidebar /> // both fetch in parallel const header = await fetchHeader(); return <><div>{header}</div><Sidebar /></> Critical
16 15 Server After Non-blocking after non-blocking logging React/Next.js Use Next.js after() to schedule work after response is sent Use after() for logging/analytics Block response for non-critical operations after(async () => { await logAction() }); return Response.json(data) await logAction(); return Response.json(data) Medium
17 16 Client SWR Deduplication swr dedup cache revalidate React/Next.js Use SWR for automatic request deduplication and caching Use useSWR for client data fetching Manual fetch in useEffect const { data } = useSWR('/api/users', fetcher) useEffect(() => { fetch('/api/users').then(setUsers) }, []) Medium-High
18 17 Client Event Listener Dedup event listener deduplicate global React/Next.js Share global event listeners across component instances Use useSWRSubscription for shared listeners Register listener per component instance useSWRSubscription('global-keydown', () => { window.addEventListener... }) useEffect(() => { window.addEventListener('keydown', handler) }, []) Low
19 18 Rerender Defer State Reads state read callback subscription React/Next.js Don't subscribe to state only used in callbacks Read state on-demand in callbacks Subscribe to state used only in handlers const handleClick = () => { const params = new URLSearchParams(location.search) } const params = useSearchParams(); const handleClick = () => { params.get('ref') } Medium
20 19 Rerender Memoized Components memo extract expensive React/Next.js Extract expensive work into memoized components for early returns Extract to memo() components Compute expensive values before early return const UserAvatar = memo(({ user }) => ...); if (loading) return <Skeleton /> const avatar = useMemo(() => compute(user)); if (loading) return <Skeleton /> Medium
21 20 Rerender Narrow Dependencies effect dependency primitive React/Next.js Specify primitive dependencies instead of objects in effects Use primitive values in dependency arrays Use object references as dependencies useEffect(() => { console.log(user.id) }, [user.id]) useEffect(() => { console.log(user.id) }, [user]) Low
22 21 Rerender Derived State derived boolean subscription React/Next.js Subscribe to derived booleans instead of continuous values Use derived boolean state Subscribe to continuous values const isMobile = useMediaQuery('(max-width: 767px)') const width = useWindowWidth(); const isMobile = width < 768 Medium
23 22 Rerender Functional setState functional setstate callback React/Next.js Use functional setState updates for stable callbacks and no stale closures Use functional form: setState(curr => ...) Reference state directly in setState setItems(curr => [...curr, newItem]) setItems([...items, newItem]) // items in deps Medium
24 23 Rerender Lazy State Init usestate lazy initialization React/Next.js Pass function to useState for expensive initial values Use function form for expensive init Compute expensive value directly useState(() => buildSearchIndex(items)) useState(buildSearchIndex(items)) // runs every render Medium
25 24 Rerender Transitions starttransition non-urgent React/Next.js Mark frequent non-urgent state updates as transitions Use startTransition for non-urgent updates Block UI on every state change startTransition(() => setScrollY(window.scrollY)) setScrollY(window.scrollY) // blocks on every scroll Medium
26 25 Rendering SVG Animation Wrapper svg animation wrapper div React/Next.js Wrap SVG in div and animate wrapper for hardware acceleration Animate div wrapper around SVG Animate SVG element directly <div class='animate-spin'><svg>...</svg></div> <svg class='animate-spin'>...</svg> Low
27 26 Rendering Content Visibility content-visibility auto React/Next.js Apply content-visibility: auto to defer off-screen rendering Use content-visibility for long lists Render all list items immediately .item { content-visibility: auto; contain-intrinsic-size: 0 80px } Render 1000 items without optimization High
28 27 Rendering Hoist Static JSX hoist static jsx element React/Next.js Extract static JSX outside components to avoid re-creation Hoist static elements to module scope Create static elements inside components const skeleton = <div class='animate-pulse' />; function C() { return skeleton } function C() { return <div class='animate-pulse' /> } Low
29 28 Rendering Hydration No Flicker hydration mismatch flicker React/Next.js Use inline script to set client-only data before hydration Inject sync script for client-only values Use useEffect causing flash <script dangerouslySetInnerHTML={{ __html: 'el.className = localStorage.theme' }} /> useEffect(() => setTheme(localStorage.theme), []) // flickers Medium
30 29 Rendering Conditional Render conditional render ternary React/Next.js Use ternary instead of && when condition can be 0 or NaN Use explicit ternary for conditionals Use && with potentially falsy numbers {count > 0 ? <Badge>{count}</Badge> : null} {count && <Badge>{count}</Badge>} // renders '0' Low
31 30 Rendering Activity Component activity show hide preserve React/Next.js Use Activity component to preserve state/DOM for toggled components Use Activity for expensive toggle components Unmount/remount on visibility toggle <Activity mode={isOpen ? 'visible' : 'hidden'}><Menu /></Activity> {isOpen && <Menu />} // loses state Medium
32 31 JS Perf Batch DOM CSS batch dom css reflow React/Next.js Group CSS changes via classes or cssText to minimize reflows Use class toggle or cssText Change styles one property at a time element.classList.add('highlighted') el.style.width='100px'; el.style.height='200px' Medium
33 32 JS Perf Index Map Lookup map index lookup find React/Next.js Build Map for repeated lookups instead of multiple .find() calls Build index Map for O(1) lookups Use .find() in loops const byId = new Map(users.map(u => [u.id, u])); byId.get(id) users.find(u => u.id === order.userId) // O(n) each time Low-Medium
34 33 JS Perf Cache Property Access cache property loop React/Next.js Cache object property lookups in hot paths Cache values before loops Access nested properties in loops const val = obj.config.settings.value; for (...) process(val) for (...) process(obj.config.settings.value) Low-Medium
35 34 JS Perf Cache Function Results memoize cache function React/Next.js Use module-level Map to cache repeated function results Use Map cache for repeated calls Recompute same values repeatedly const cache = new Map(); if (cache.has(x)) return cache.get(x) slugify(name) // called 100 times same input Medium
36 35 JS Perf Cache Storage API localstorage cache read React/Next.js Cache localStorage/sessionStorage reads in memory Cache storage reads in Map Read storage on every call if (!cache.has(key)) cache.set(key, localStorage.getItem(key)) localStorage.getItem('theme') // every call Low-Medium
37 36 JS Perf Combine Iterations combine filter map loop React/Next.js Combine multiple filter/map into single loop Single loop for multiple categorizations Chain multiple filter() calls for (u of users) { if (u.isAdmin) admins.push(u); if (u.isTester) testers.push(u) } users.filter(admin); users.filter(tester); users.filter(inactive) Low-Medium
38 37 JS Perf Length Check First length check array compare React/Next.js Check array lengths before expensive comparisons Early return if lengths differ Always run expensive comparison if (a.length !== b.length) return true; // then compare a.sort().join() !== b.sort().join() // even when lengths differ Medium-High
39 38 JS Perf Early Return early return exit function React/Next.js Return early when result is determined to skip processing Return immediately on first error Process all items then check errors for (u of users) { if (!u.email) return { error: 'Email required' } } let hasError; for (...) { if (!email) hasError=true }; if (hasError)... Low-Medium
40 39 JS Perf Hoist RegExp regexp hoist module React/Next.js Don't create RegExp inside render - hoist or memoize Hoist RegExp to module scope Create RegExp every render const EMAIL_RE = /^[^@]+@[^@]+$/; function validate() { EMAIL_RE.test(x) } function C() { const re = new RegExp(pattern); re.test(x) } Low-Medium
41 40 JS Perf Loop Min Max loop min max sort React/Next.js Use loop for min/max instead of sort - O(n) vs O(n log n) Single pass loop for min/max Sort array to find min/max let max = arr[0]; for (x of arr) if (x > max) max = x arr.sort((a,b) => b-a)[0] // O(n log n) Low
42 41 JS Perf Set Map Lookups set map includes has React/Next.js Use Set/Map for O(1) lookups instead of array.includes() Convert to Set for membership checks Use .includes() for repeated checks const allowed = new Set(['a','b']); allowed.has(id) const allowed = ['a','b']; allowed.includes(id) Low-Medium
43 42 JS Perf toSorted Immutable tosorted sort immutable React/Next.js Use toSorted() instead of sort() to avoid mutating arrays Use toSorted() for immutability Mutate arrays with sort() users.toSorted((a,b) => a.name.localeCompare(b.name)) users.sort((a,b) => a.name.localeCompare(b.name)) // mutates Medium-High
44 43 Advanced Event Handler Refs useeffectevent ref handler React/Next.js Store callbacks in refs for stable effect subscriptions Use useEffectEvent for stable handlers Re-subscribe on every callback change const onEvent = useEffectEvent(handler); useEffect(() => { listen(onEvent) }, []) useEffect(() => { listen(handler) }, [handler]) // re-subscribes Low
45 44 Advanced useLatest Hook uselatest ref callback React/Next.js Access latest values in callbacks without adding to dependency arrays Use useLatest for fresh values in stable callbacks Add callback to effect dependencies const cbRef = useLatest(cb); useEffect(() => { setTimeout(() => cbRef.current()) }, []) useEffect(() => { setTimeout(() => cb()) }, [cb]) // re-runs Low