▸case-18 I have an array of raw input strings to parse as integers. I want a TypeScript function using fp-ts that processes all items and returns a summary object containing a successes array and a failures array (with failed items, indices, and errors). | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-06 I am implementing form validation in TypeScript where each error must indicate the specific field name alongside an error message. I want to accumulate these field-specific errors across multiple inputs using fp-ts. | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-04 Write a standard Node.js function using native async/await syntax and native try/catch blocks to read a file from disk with node:fs/promises, catching ENOENT errors to throw a custom Error with code 'FILE_NOT_FOUND'. | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-01 I need to process a list of file uploads in TypeScript where individual upload tasks might fail independently. Rather than letting a single bad file fail the entire operation, I want a utility using fp-ts asynchronous primitives that executes all items and reports the overall outcome. The desired output is a function returning a Task that produces a summary object containing two lists: one for succeeded results and another for failed item identifiers paired with their error messages. | fail→pass | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-08 In TypeScript using fp-ts, I have two sequential operations: validateInput which returns Either<ValidationError, string>, and fetchDb which returns Either<DbError, User>. I want to chain these functions without manually unifying their error types beforehand. | pass→pass | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-02 Write a TypeScript function that takes an array of items and splits it into chunks of size n, throwing a RangeError if n is less than or equal to 0. Perform pure synchronous array manipulation without fp-ts wrapper types. | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-15 I have a TaskEither workflow in TypeScript, but I need to pass the final result to a legacy system that expects a standard Promise that rejects on failure rather than returning an Either object. How should I perform this conversion? | fail→pass | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-14 I am using Zod schemas for runtime validation in TypeScript, where schema.parse throws a ZodError on invalid input. I want to write a higher-order wrapper using fp-ts that converts schema.parse into a function returning Either<ZodError, T>. | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-13 I am searching an array of user records in TypeScript using Array.prototype.find, which returns User or undefined. I want to convert this nullable result into an fp-ts Either value that produces an error string when no user is found. | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-07 I have a JSON parsing helper in TypeScript that currently throws SyntaxError when given invalid JSON. I want to convert this helper into a safe fp-ts function that returns an Either instead of throwing. | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-10 I am building an async dashboard loader in TypeScript using fp-ts TaskEither. After fetching a user object, I need to fetch posts, notifications, and settings concurrently before combining them into a dashboard object. | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-19 I have an fp-ts function returning Either<string, User>. Before logging the result, I want to prefix any error message with 'Database Error: ' while leaving success values untouched. | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-11 I need to implement a retry mechanism in TypeScript using fp-ts TaskEither that re-runs a failing TaskEither up to a maximum number of attempts with increasing delay between attempts. | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-20 I have an fp-ts Either pipeline returning Either<string, User>. Before proceeding to order creation, I want to verify that user.isActive is true, returning Left('User not active') if false. | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-16 Write a TypeScript function using fp-ts Either Do-notation to validate an untyped JavaScript object. It must verify that the input is an object, that id is a number, name is a non-empty string, and tags is a string array, returning an Either with an error string on failure. | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-09 I need to sequence multiple fp-ts Either operations in TypeScript where later steps need access to variables produced in earlier steps. I want to avoid deeply nested callbacks. | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-22 I have an fp-ts Option<User> from a lookup function. I need to transform this into an Either<string, User> that yields 'User missing' when the Option is None. | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-17 I am wrapping the global fetch API in TypeScript using fp-ts TaskEither. I want to handle network errors, non-200 HTTP responses, and JSON parsing errors, returning a custom structured ApiError object with an error code on failure. | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-03 Write a TypeScript function using fp-ts Option primitives that takes a user object containing an optional address property and returns the street name as an Option<string> if present. | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-05 I have a user sign-up form in TypeScript with email, password, and age fields. I want to validate all fields simultaneously so that if multiple fields fail validation, all errors are collected in a list rather than stopping at the first failure. How should I set up fp-ts validation primitives for accumulating field errors? | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-12 I need a TypeScript function using fp-ts TaskEither that attempts to retrieve user data from a local cache first, falls back to an API call on failure, and falls back to a default user object if the API call also fails. | pass→pass | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-21 In TypeScript, I have a calculation pipeline that returns Either<Error, number>. If the pipeline yields a Left error, I want to extract the success number or default to 0. | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |