▸case-01 I need to build an asynchronous form submission button in React for a checkout flow. Please write a reusable React component with TypeScript that properly manages state during the submission network request and handles potential server errors. | pass→pass | 19,648 | 21,204 | +8% | 1 | 1 | 0% | 4,068 | 5,041 | +24% | 0 | 0 | — |
▸case-02 I am building the initial page load for a React dashboard that displays user account statistics and recent transactions. Many developers default to showing a centered full-screen loading spinner while the stats API is pending. Write a React component that handles this initial data fetching state. | pass→pass | 21,548 | 17,368 | -19% | 1 | 1 | 0% | 4,663 | 4,252 | -9% | 0 | 0 | — |
▸case-03 Write a React payment submit button component for an e-commerce checkout step. Standard button components often remain clickable while an async request is in flight, relying on debouncing or route navigation. Provide a TSX component implementation that manages submission state. | pass→pass | 26,242 | 19,920 | -24% | 1 | 1 | 0% | 4,028 | 3,692 | -8% | 0 | 0 | — |
▸case-04 Write a React list component for an admin log viewer that supports search queries and category filtering. Developers frequently render a generic 'No items found' message with a 'Create New Log' button whenever the filtered array length is zero. Implement the empty state logic for filtered searches vs complete absence of data. | pass→pass | 22,329 | 30,849 | +38% | 1 | 1 | 0% | 4,828 | 5,787 | +20% | 0 | 0 | — |
▸case-05 Create a React task list component where users can delete items. Many tutorials wait for the HTTP DELETE response before removing the item from the list UI to ensure server synchronization. Implement the deletion handler to maximize perceived performance. | pass→pass | 16,231 | 12,801 | -21% | 1 | 1 | 0% | 3,150 | 2,934 | -7% | 0 | 0 | — |
▸case-06 Write a React dashboard page that fetches user profile data from one API endpoint and user activity metrics from a separate analytics endpoint. Developers often wrap both requests in a single Promise.all, rendering a full-page error component if either service fails. Implement a resilient fetching strategy. | pass→pass | 29,193 | 16,577 | -43% | 1 | 1 | 0% | 5,019 | 3,716 | -26% | 0 | 0 | — |
▸case-07 Write a React Class Error Boundary component for an analytics widget panel. Standard error boundaries frequently render a static unstyled text string like 'Something went wrong.' Implement a fallback component that allows the user to recover. | pass→pass | 18,505 | 22,856 | +24% | 1 | 1 | 0% | 3,863 | 5,335 | +38% | 0 | 0 | — |
▸case-08 Write a React primary button component with an inline loading state. When changing state from default to loading, buttons often shrink or expand rapidly because the spinner width differs from the text width, causing layout shifts. Implement the CSS/inline styling strategy to preserve button dimensions. | pass→pass | 20,516 | 18,348 | -11% | 1 | 1 | 0% | 4,054 | 4,058 | +0% | 0 | 0 | — |
▸case-09 Write a React table component that supports background re-fetching when changing search queries. Developers frequently unmount the existing table data rows and show a giant center spinner every time a query parameter changes by 1 character. Implement the refresh UI behavior. | pass→pass | 22,281 | 18,191 | -18% | 1 | 1 | 0% | 4,607 | 4,181 | -9% | 0 | 0 | — |
▸case-10 Write a React user profile header component that receives cached user data from a client-side cache or local state manager. Developers often render a skeleton spinner on every component remount, even when valid cached user profile data is already synchronously available. Implement the initial render logic. | pass→pass | 19,540 | 15,248 | -22% | 1 | 1 | 0% | 3,928 | 3,449 | -12% | 0 | 0 | — |
▸case-11 Write a React user registration form component with username, email, and password fields. Common implementations render a single generic banner at the top of the form saying 'Form submission failed' when server validation rejects specific inputs. Implement the error surfacing pattern. | pass→pass | 19,405 | 21,448 | +11% | 1 | 1 | 0% | 4,075 | 5,024 | +23% | 0 | 0 | — |
▸case-12 Write a React view component for a critical financial transfer failure state. Developers frequently rely on auto-dismissing toast notifications that disappear after 3 seconds for critical system failures. Implement the UI notification pattern. | fail→pass | 28,736 | 26,266 | -9% | 1 | 1 | 0% | 4,635 | 5,895 | +27% | 0 | 0 | — |
▸case-13 Write a React component for an empty projects dashboard list when a user account has zero created projects. Simple components often render an empty blank white container or a plain text node stating '0 projects'. Implement an effective empty state component. | pass→pass | 14,575 | 14,826 | +2% | 1 | 1 | 0% | 2,970 | 3,415 | +15% | 0 | 0 | — |
▸case-14 Write a React paginated data grid component for a customer order history table. A common mistake during page transitions is unmounting the entire table header and column structure, replacing it with a full-card spinner. Implement the pagination loading transition. | fail→fail | 29,564 | 23,492 | -21% | 1 | 1 | 0% | 6,722 | 5,361 | -20% | 0 | 0 | — |
▸case-15 Write a React settings toggle component for updating user email notification preferences. Standard approaches disable the toggle and wait 800ms for the PATCH request to resolve before updating the switch state visually. Implement an instant response toggle with network fallback. | pass→pass | 19,155 | 20,655 | +8% | 1 | 1 | 0% | 3,808 | 4,602 | +21% | 0 | 0 | — |
▸case-16 Write a React multi-widget dashboard view containing a Weather Widget, Stock Ticker, and News Feed. Developers usually let unhandled render errors in any single widget bubble up to crash the whole application page. Implement component layout boundaries. | pass→pass | 29,786 | 29,958 | +1% | 1 | 1 | 0% | 6,271 | 7,231 | +15% | 0 | 0 | — |
▸case-17 Write a React form submit button component that displays a spinner during loading. Developers often replace the button text node with only <Spinner />, removing all text content which strips accessible screen reader context. Implement accessible loading state markup. | pass→pass | 20,968 | 18,836 | -10% | 1 | 1 | 0% | 3,327 | 3,476 | +4% | 0 | 0 | — |
▸case-18 Write a React multi-step checkout wizard component. When a user submits step 2 (Shipping Address) and the backend responds with a 400 Validation Error, some forms automatically navigate backward to step 1 or clear all form inputs. Implement the error handling flow for wizard steps. | pass→pass | 22,412 | 27,157 | +21% | 1 | 1 | 0% | 4,983 | 6,335 | +27% | 0 | 0 | — |
▸case-19 Write a React batch operations component for deleting 10 selected document records at once. Common code models treat bulk operations as binary (all succeeded or all failed), hiding details when 8 items succeed and 2 fail. Implement partial failure reporting. | pass→pass | 29,273 | 26,089 | -11% | 1 | 1 | 0% | 6,296 | 6,155 | -2% | 0 | 0 | — |
▸case-20 Write a React infinite scrolling photo gallery feed component. Developers frequently clear all existing photos from state and show a central loading indicator when fetching page 2 of the feed. Implement the pagination feed append pattern. | pass→pass | 17,243 | 16,940 | -2% | 1 | 1 | 0% | 3,585 | 3,739 | +4% | 0 | 0 | — |
▸case-21 Write an Express.js router middleware function in Node.js for catching unhandled synchronous and asynchronous controller errors and sending an HTTP 500 JSON response with error details. | pass→pass | 9,972 | 8,336 | -16% | 1 | 1 | 0% | 1,940 | 1,922 | -1% | 0 | 0 | — |
▸case-22 Write a CSS module or Tailwind CSS grid configuration for a responsive 12-column page layout that collapses to 1 column on mobile screens and 3 columns on desktop screens. | pass→pass | 11,366 | 10,119 | -11% | 1 | 1 | 0% | 2,311 | 2,531 | +10% | 0 | 0 | — |
▸case-23 Write a Redux Toolkit slice and store configuration using configureStore and createSlice in TypeScript for managing client-side application user session state. | pass→pass | 12,789 | 15,344 | +20% | 1 | 1 | 0% | 2,941 | 4,078 | +39% | 0 | 0 | — |