africa/src/lib/index.js

A library to interactively create and read configuration files.

import ask from 'reloquent'
import bosom from 'bosom'
import Group from './Group'

/**
 * Ask questions and write answers to the RC file.
 * @param {_reloquent.Questions} questions The set of questions. These need to be updated to include defaults.
 * @param {string} path The path for the RC file.
 * @param {{
 * skipExisting: (boolean|undefined),
 * config: (!Object|undefined),
 * timeout: (number|undefined)
 * }} [options] Additional options.
 */
export async function askQuestionsAndWrite(questions, path, {
  skipExisting = false, config = {}, timeout,
} = {}) {
  /** @type {!Object<string, !Group>} */
  const groups = {}

  let current = {}

  const q = Object.entries(questions).reduce((acc, [key, question]) => {
    if (question instanceof Group) {
      groups[key] = question
      return acc
    }
    acc[key] = question
    return acc
  }, {})

  let answers = await ask(q, timeout)

  try {
    current = await bosom(path)
  } catch (err) {
    // ok
  }

  if (skipExisting) {
    answers = skipAnswers(answers, config, current) || {}
  }

  const ga = await Object.entries(groups).reduce(async (acc, [key, group]) => {
    acc = await acc
    let g = await ask(group.questions, timeout)
    if (skipExisting) g = skipAnswers(g, config[key], current[key])
    if (g) acc[key] = g
    return acc
  }, {})

  // answers not from questions but in config anyhow

  const extra = skipAnswers(current, config, current) || {}
  const total = { ...extra, ...answers, ...ga }
  await bosom(path, total, { space: 2 })
  return total
}

const skipAnswers = (answers, config = {}, current = {}) => {
  let allSkipped = true
  const skipped = Object.entries(answers).reduce((acc, [key, val]) => {
    const CURRENT = current[key]
    const DEFAULT = config[key]

    if (val == DEFAULT && val != CURRENT) return acc
    allSkipped = false
    acc[key] = val
    return acc
  }, {})
  if (allSkipped) return null
  return skipped
}

/**
 * Merge two configurations, with `a` as base one, such that its properties won't be overridden by `b`.
 * @param {!Object} a The base configuration.
 * @param {!Object} b The extension to configuration.
 */
export const merge = (a, b) => {
  return Object.entries(b).reduce((acc, [k, value]) => {
    if (typeof value == 'object' && value !== null && typeof a[k] == 'object') {
      acc[k] = merge(a[k], value)
    }
    else acc[k] = value
    return acc
  }, a)
}

/**
 * Adds default value from the config.
 * @param {_reloquent.Questions} questions A set of questions to extend with default value from the existing config.
 * @param {!Object} current Current configuration object (answers).
 * @returns {_reloquent.Questions} Questions with updated defaultValue where answers were present in the passed config object.
 */
const extendQuestions = (questions, current) => {
  const q = Object.entries(questions).reduce((acc, [key, question]) => {
    const defaultValue = current[key]
    if (!defaultValue) {
      acc[key] = question
      return acc
    }

    let value = typeof question == 'string' ? { text: question } : question
    if (question instanceof Group) {
      question.questions = extendQuestions(question.questions, defaultValue)
    } else {
      value = { ...value, defaultValue }
    }

    acc[key] = value
    return acc
  }, {})
  return q
}

/**
 * Ask questions while adding default values when asking.
 * @param {_reloquent.Questions} questions
 * @param {string} path The path to the rc file.
 * @param {!Object} config Current answers.
 * @param {number} [timeout]
 * @param {{ skipExisting: (boolean|undefined) }} [opts]
 */
export const forceQuestions = async (questions, path, config, timeout, { skipExisting } = {}) => {
  const q = extendQuestions(questions, config)
  const conf = await askQuestionsAndWrite(q, path, { timeout, skipExisting, config })
  return conf
}

/**
 * @suppress {nonStandardJsDocs}
 * @typedef {import('../..').Questions} _reloquent.Questions
 */