55 lines
13 KiB
Plaintext
55 lines
13 KiB
Plaintext
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No,Category,Guideline,Description,Do,Don't,Code Good,Code Bad,Severity,Docs URL
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1,State,Use useState for local state,Simple component state should use useState hook,useState for form inputs toggles counters,Class components this.state,"const [count, setCount] = useState(0)",this.state = { count: 0 },Medium,https://react.dev/reference/react/useState
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2,State,Lift state up when needed,Share state between siblings by lifting to parent,Lift shared state to common ancestor,Prop drilling through many levels,Parent holds state passes down,Deep prop chains,Medium,https://react.dev/learn/sharing-state-between-components
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3,State,Use useReducer for complex state,Complex state logic benefits from reducer pattern,useReducer for state with multiple sub-values,Multiple useState for related values,useReducer with action types,5+ useState calls that update together,Medium,https://react.dev/reference/react/useReducer
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4,State,Avoid unnecessary state,Derive values from existing state when possible,Compute derived values in render,Store derivable values in state,const total = items.reduce(...),"const [total, setTotal] = useState(0)",High,https://react.dev/learn/choosing-the-state-structure
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5,State,Initialize state lazily,Use function form for expensive initial state,useState(() => computeExpensive()),useState(computeExpensive()),useState(() => JSON.parse(data)),useState(JSON.parse(data)),Medium,https://react.dev/reference/react/useState#avoiding-recreating-the-initial-state
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6,Effects,Clean up effects,Return cleanup function for subscriptions timers,Return cleanup function in useEffect,No cleanup for subscriptions,useEffect(() => { sub(); return unsub; }),useEffect(() => { subscribe(); }),High,https://react.dev/reference/react/useEffect#connecting-to-an-external-system
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7,Effects,Specify dependencies correctly,Include all values used inside effect in deps array,All referenced values in dependency array,Empty deps with external references,[value] when using value in effect,[] when using props/state in effect,High,https://react.dev/reference/react/useEffect#specifying-reactive-dependencies
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8,Effects,Avoid unnecessary effects,Don't use effects for transforming data or events,Transform data during render handle events directly,useEffect for derived state or event handling,const filtered = items.filter(...),useEffect(() => setFiltered(items.filter(...))),High,https://react.dev/learn/you-might-not-need-an-effect
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9,Effects,Use refs for non-reactive values,Store values that don't trigger re-renders in refs,useRef for interval IDs DOM elements,useState for values that don't need render,const intervalRef = useRef(null),"const [intervalId, setIntervalId] = useState()",Medium,https://react.dev/reference/react/useRef
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10,Rendering,Use keys properly,Stable unique keys for list items,Use stable IDs as keys,Array index as key for dynamic lists,key={item.id},key={index},High,https://react.dev/learn/rendering-lists#keeping-list-items-in-order-with-key
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11,Rendering,Memoize expensive calculations,Use useMemo for costly computations,useMemo for expensive filtering/sorting,Recalculate every render,"useMemo(() => expensive(), [deps])",const result = expensiveCalc(),Medium,https://react.dev/reference/react/useMemo
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12,Rendering,Memoize callbacks passed to children,Use useCallback for functions passed as props,useCallback for handlers passed to memoized children,New function reference every render,"useCallback(() => {}, [deps])",const handler = () => {},Medium,https://react.dev/reference/react/useCallback
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13,Rendering,Use React.memo wisely,Wrap components that render often with same props,memo for pure components with stable props,memo everything or nothing,memo(ExpensiveList),memo(SimpleButton),Low,https://react.dev/reference/react/memo
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14,Rendering,Avoid inline object/array creation in JSX,Create objects outside render or memoize,Define style objects outside component,Inline objects in props,<div style={styles.container}>,<div style={{ margin: 10 }}>,Medium,
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15,Components,Keep components small and focused,Single responsibility for each component,One concern per component,Large multi-purpose components,<UserAvatar /><UserName />,<UserCard /> with 500 lines,Medium,
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16,Components,Use composition over inheritance,Compose components using children and props,Use children prop for flexibility,Inheritance hierarchies,<Card>{content}</Card>,class SpecialCard extends Card,Medium,https://react.dev/learn/thinking-in-react
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17,Components,Colocate related code,Keep related components and hooks together,Related files in same directory,Flat structure with many files,components/User/UserCard.tsx,components/UserCard.tsx + hooks/useUser.ts,Low,
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18,Components,Use fragments to avoid extra DOM,Fragment or <> for multiple elements without wrapper,<> for grouping without DOM node,Extra div wrappers,<>{items.map(...)}</>,<div>{items.map(...)}</div>,Low,https://react.dev/reference/react/Fragment
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19,Props,Destructure props,Destructure props for cleaner component code,Destructure in function signature,props.name props.value throughout,"function User({ name, age })",function User(props),Low,
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20,Props,Provide default props values,Use default parameters or defaultProps,Default values in destructuring,Undefined checks throughout,function Button({ size = 'md' }),if (size === undefined) size = 'md',Low,
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21,Props,Avoid prop drilling,Use context or composition for deeply nested data,Context for global data composition for UI,Passing props through 5+ levels,<UserContext.Provider>,<A user={u}><B user={u}><C user={u}>,Medium,https://react.dev/learn/passing-data-deeply-with-context
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22,Props,Validate props with TypeScript,Use TypeScript interfaces for prop types,interface Props { name: string },PropTypes or no validation,interface ButtonProps { onClick: () => void },Button.propTypes = {},Medium,
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23,Events,Use synthetic events correctly,React normalizes events across browsers,e.preventDefault() e.stopPropagation(),Access native event unnecessarily,onClick={(e) => e.preventDefault()},onClick={(e) => e.nativeEvent.preventDefault()},Low,https://react.dev/reference/react-dom/components/common#react-event-object
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24,Events,Avoid binding in render,Use arrow functions in class or hooks,Arrow functions in functional components,bind in render or constructor,const handleClick = () => {},this.handleClick.bind(this),Medium,
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25,Events,Pass event handlers not call results,Pass function reference not invocation,onClick={handleClick},onClick={handleClick()} causing immediate call,onClick={handleClick},onClick={handleClick()},High,
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26,Forms,Controlled components for forms,Use state to control form inputs,value + onChange for inputs,Uncontrolled inputs with refs,<input value={val} onChange={setVal}>,<input ref={inputRef}>,Medium,https://react.dev/reference/react-dom/components/input#controlling-an-input-with-a-state-variable
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27,Forms,Handle form submission properly,Prevent default and handle in submit handler,onSubmit with preventDefault,onClick on submit button only,<form onSubmit={handleSubmit}>,<button onClick={handleSubmit}>,Medium,
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28,Forms,Debounce rapid input changes,Debounce search/filter inputs,useDeferredValue or debounce for search,Filter on every keystroke,useDeferredValue(searchTerm),useEffect filtering on every change,Medium,https://react.dev/reference/react/useDeferredValue
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29,Hooks,Follow rules of hooks,Only call hooks at top level and in React functions,Hooks at component top level,Hooks in conditions loops or callbacks,"const [x, setX] = useState()","if (cond) { const [x, setX] = useState() }",High,https://react.dev/reference/rules/rules-of-hooks
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30,Hooks,Custom hooks for reusable logic,Extract shared stateful logic to custom hooks,useCustomHook for reusable patterns,Duplicate hook logic across components,const { data } = useFetch(url),Duplicate useEffect/useState in components,Medium,https://react.dev/learn/reusing-logic-with-custom-hooks
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31,Hooks,Name custom hooks with use prefix,Custom hooks must start with use,useFetch useForm useAuth,fetchData or getData for hook,function useFetch(url),function fetchData(url),High,
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32,Context,Use context for global data,Context for theme auth locale,Context for app-wide state,Context for frequently changing data,<ThemeContext.Provider>,Context for form field values,Medium,https://react.dev/learn/passing-data-deeply-with-context
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33,Context,Split contexts by concern,Separate contexts for different domains,ThemeContext + AuthContext,One giant AppContext,<ThemeProvider><AuthProvider>,<AppProvider value={{theme user...}}>,Medium,
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34,Context,Memoize context values,Prevent unnecessary re-renders with useMemo,useMemo for context value object,New object reference every render,"value={useMemo(() => ({...}), [])}","value={{ user, theme }}",High,
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35,Performance,Use React DevTools Profiler,Profile to identify performance bottlenecks,Profile before optimizing,Optimize without measuring,React DevTools Profiler,Guessing at bottlenecks,Medium,https://react.dev/learn/react-developer-tools
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36,Performance,Lazy load components,Use React.lazy for code splitting,lazy() for routes and heavy components,Import everything upfront,const Page = lazy(() => import('./Page')),import Page from './Page',Medium,https://react.dev/reference/react/lazy
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37,Performance,Virtualize long lists,Use windowing for lists over 100 items,react-window or react-virtual,Render thousands of DOM nodes,<VirtualizedList items={items}/>,{items.map(i => <Item />)},High,
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38,Performance,Batch state updates,React 18 auto-batches but be aware,Let React batch related updates,Manual batching with flushSync,setA(1); setB(2); // batched,flushSync(() => setA(1)),Low,https://react.dev/learn/queueing-a-series-of-state-updates
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39,ErrorHandling,Use error boundaries,Catch JavaScript errors in component tree,ErrorBoundary wrapping sections,Let errors crash entire app,<ErrorBoundary><App/></ErrorBoundary>,No error handling,High,https://react.dev/reference/react/Component#catching-rendering-errors-with-an-error-boundary
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40,ErrorHandling,Handle async errors,Catch errors in async operations,try/catch in async handlers,Unhandled promise rejections,try { await fetch() } catch(e) {},await fetch() // no catch,High,
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41,Testing,Test behavior not implementation,Test what user sees and does,Test renders and interactions,Test internal state or methods,expect(screen.getByText('Hello')),expect(component.state.name),Medium,https://testing-library.com/docs/react-testing-library/intro/
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42,Testing,Use testing-library queries,Use accessible queries,getByRole getByLabelText,getByTestId for everything,getByRole('button'),getByTestId('submit-btn'),Medium,https://testing-library.com/docs/queries/about#priority
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43,Accessibility,Use semantic HTML,Proper HTML elements for their purpose,button for clicks nav for navigation,div with onClick for buttons,<button onClick={...}>,<div onClick={...}>,High,https://react.dev/reference/react-dom/components#all-html-components
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44,Accessibility,Manage focus properly,Handle focus for modals dialogs,Focus trap in modals return focus on close,No focus management,useEffect to focus input,Modal without focus trap,High,
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45,Accessibility,Announce dynamic content,Use ARIA live regions for updates,aria-live for dynamic updates,Silent updates to screen readers,"<div aria-live=""polite"">{msg}</div>",<div>{msg}</div>,Medium,
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46,Accessibility,Label form controls,Associate labels with inputs,htmlFor matching input id,Placeholder as only label,"<label htmlFor=""email"">Email</label>","<input placeholder=""Email""/>",High,
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47,TypeScript,Type component props,Define interfaces for all props,interface Props with all prop types,any or missing types,interface Props { name: string },function Component(props: any),High,
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48,TypeScript,Type state properly,Provide types for useState,useState<Type>() for complex state,Inferred any types,useState<User | null>(null),useState(null),Medium,
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49,TypeScript,Type event handlers,Use React event types,React.ChangeEvent<HTMLInputElement>,Generic Event type,onChange: React.ChangeEvent<HTMLInputElement>,onChange: Event,Medium,
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50,TypeScript,Use generics for reusable components,Generic components for flexible typing,Generic props for list components,Union types for flexibility,<List<T> items={T[]}>,<List items={any[]}>,Medium,
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51,Patterns,Container/Presentational split,Separate data logic from UI,Container fetches presentational renders,Mixed data and UI in one,<UserContainer><UserView/></UserContainer>,<User /> with fetch and render,Low,
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52,Patterns,Render props for flexibility,Share code via render prop pattern,Render prop for customizable rendering,Duplicate logic across components,<DataFetcher render={data => ...}/>,Copy paste fetch logic,Low,https://react.dev/reference/react/cloneElement#passing-data-with-a-render-prop
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53,Patterns,Compound components,Related components sharing state,Tab + TabPanel sharing context,Prop drilling between related,<Tabs><Tab/><TabPanel/></Tabs>,<Tabs tabs={[]} panels={[...]}/>,Low,
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