▸case-12 When rendering the top featured user from an array of users in a React component, array indexing users[0] can return undefined and cause runtime errors. Show how to safely extract and render the first element using fp-ts Array and Option modules. | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-07 We want to write a reusable data fetching hook in React that wraps API calls in a functional async construct to ensure HTTP status errors and exceptions are captured as typed errors before updating state. Show how to implement this using fp-ts async task types. | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-15 We need to write a unit test using React Testing Library for a component that uses context-based dependency injection for service calls. How should mock services be structured and passed during testing? | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-19 How do you use useStableEffect from fp-ts-react-stable-hooks to trigger side effects based on an Option value without infinite re-renders? Show the import and usage signature. | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-03 We have a user profile view where user data starts uninitialized, updates on login, and clears on logout. Developers usually set state to null or undefined and write conditional checks. How should we model and render optional state in React using fp-ts algebraic data types so missing state is handled explicitly? Provide a React component example. | pass→pass | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-21 We are setting up form validation using React Hook Form and Zod schema validation for a user registration form. How do we hook up zodResolver with useForm to validate form inputs? | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-06 We are building a React form where each form field needs to display its own distinct validation error message next to the field input, rather than showing a generic list at the top. Show how to perform validation returning field-keyed error objects using fp-ts Either. | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-13 We want to find an admin user inside an array of user objects in a React component and render an admin badge if found, or null if not found. Show how to achieve this functionally without raw Array.prototype.find. | fail→pass | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-14 In a React modal component, we have optional props like title that should only be included in the modal's props object if present. Show how to conditionally build prop objects using fp-ts Option. | fail→pass | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-17 Show how to write a custom React hook useRemoteData that accepts an async fetch function, initializes state to notAsked, sets loading during execution, and transitions state to success or failure upon completion. | fail→pass | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-18 Compare handling nullable state with standard null vs fp-ts Option in React. Provide code demonstrating how state update handlers transition from O.none to O.some in a login handler. | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-02 In our React functional components, whenever we store an fp-ts Option in component state or pass it to useEffect dependency arrays, the component re-renders continuously or re-runs side effects because object references are recreated on every render cycle. Can you show me how to structure component state and effect hooks to maintain referential stability when dealing with fp-ts data structures? | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-09 We need to load user data, site statistics, and pending notifications concurrently when a dashboard component mounts in React. Instead of multiple separate promise calls or Promise.all with raw try/catch blocks, how do we perform parallel async requests using fp-ts TaskEither? | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-01 We are converting our data fetching hooks in our React app to use functional programming patterns. Currently, we manage API states with separate booleans like loading and error, which leads to invalid edge cases in our render logic. Show me how to model API fetching states using a strict sum type with explicitly tag-discriminated states, along with a custom React hook and UI fold helper to safely render loading, failure, and success views. | fail→pass | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-04 In a React application, we have nested configuration properties where the user object or its nested settings object might be missing. We want to extract a nested property like theme with a default value of 'light' without using optional chaining (?.) or multiple if checks. Show how to chain optional transformations in functional TypeScript. | fail→pass | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-05 In a React signup form, we want to validate name, email, and password fields simultaneously. Standard validation functions stop at the first error or require manual array pushing. How do we collect all validation errors across all fields into a single list using functional applicative validation with fp-ts? | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-08 In our React application, after fetching a user profile from /api/users/:id, we need to fetch their posts from /api/users/:id/posts using the retrieved user ID. How can we chain these two asynchronous API calls functionally using fp-ts TaskEither so error handling remains unified? | fail→pass | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-10 In a React application using fp-ts, we want to inject API services and analytics dependencies into components using Context so that we can easily swap them out during unit tests without mocking global fetch. How should we set up the React context, provider, and custom hook for dependency injection? | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-11 We are upgrading a form in our React 19 application to use useActionState. We want to integrate fp-ts validation functions so form submissions return either collected errors or process valid data. Show how to write the action handler and form component integrating fp-ts Either. | fail→pass | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-16 When wrapping a standard browser fetch call inside TE.tryCatch, network exceptions and non-ok HTTP responses need to be normalized into a standard Error instance. Show the precise implementation of the fetchJson wrapper function using TaskEither. | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-20 We are configuring TanStack Query (React Query) v5 in a Next.js App Router application. How do we set up QueryClientProvider and configure staleTime and retry logic globally in a client component layout wrapper? | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-22 We are setting up state management using Redux Toolkit in a React TypeScript app. How do we define a slice with createSlice containing actions and reducers for updating user authentication state? | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |