@hyperfrontend/questions

Terminal prompting library with composable, functional API for text, select, confirm, and multiselect prompts

What is @hyperfrontend/questions?

A terminal prompting library built on functional programming principles. Create interactive CLI experiences with composable, type-safe prompts that return structured outcomes.

Key Features

• Pure Functions — Every prompt is a pure function returning Promise<PromptOutcome<T>>, making results predictable and easily testable
• Composable API — Build complex interactive flows by combining simple prompt functions
• Type-Safe — Full TypeScript support with discriminated unions for prompt outcomes
• Zero External Dependencies — Uses only Node.js built-ins and @hyperfrontend utilities
• Searchable Multiselect — Type-to-filter functionality for large option lists

Architecture Highlights

Each prompt follows a functional state machine pattern:

• Immutable State — All prompt state is frozen; updates create new state objects
• Explicit Outcomes — Prompts return either { result: 'submitted', value: T } or { result: 'cancelled', value: undefined }
• Terminal Abstraction — Low-level I/O is encapsulated in a Terminal interface for testability

Why Use @hyperfrontend/questions?

When building CLI tools, you need interactive prompts that are:

1. Predictable — Know exactly what a prompt returns, always
2. Composable — Chain prompts without callback hell
3. Cancellable — Handle Ctrl+C gracefully with structured cancellation
4. Lightweight — No large dependency trees for simple prompts

This library provides all four while staying true to functional programming principles.

Installation

npm install @hyperfrontend/questions

Quick Start

import { text, confirm, select, multiselect, PromptResult } from '@hyperfrontend/questions'

// Text input
const nameResult = await text({
  message: 'What is your name?',
  validate: (value) => (value.length < 2 ? 'Name too short' : undefined),
})

if (nameResult.result === PromptResult.Submitted) {
  console.log(`Hello, ${nameResult.value}!`)
}

// Text input with a live label — `renderMessage` is recomputed on every keystroke
import { style } from '@hyperfrontend/questions'

await text({
  message: 'Title:',
  renderMessage: (value) => {
    const left = 72 - value.length
    return `Title (${left >= 0 ? style.green(`${left} left`) : style.red(`${-left} over`)}):`
  },
})

// Confirmation
const continueResult = await confirm({
  message: 'Continue?',
  initial: true,
})

// Single select
const colorResult = await select({
  message: 'Pick a color:',
  choices: [
    { label: 'Red', value: 'red' },
    { label: 'Green', value: 'green', hint: 'recommended' },
    { label: 'Blue', value: 'blue' },
  ],
})

// Multiselect with search
const featuresResult = await multiselect({
  message: 'Select features:',
  choices: [
    { label: 'TypeScript', value: 'ts' },
    { label: 'ESLint', value: 'eslint' },
    { label: 'Prettier', value: 'prettier' },
  ],
  searchable: true,
  min: 1,
})

API Overview

All prompts return Promise<PromptOutcome<T>> where:

type PromptOutcome<T> = { result: 'submitted'; value: T } | { result: 'cancelled'; value: undefined }

Compatibility

License

MIT