@instructure/quiz-interactions/src/components/formula/common/util.js

A React UI component Library for quiz interaction types.

import escapeRegExp from 'lodash/escapeRegExp'
import {formatPlain} from '@instructure/quiz-i18n/util/numberFormats'
import {isScientificNotation, parseScientificNotation} from '@instructure/quiz-scientific-notation'

import additionalFunctions from './additional_functions'

const openingQuote = '`'
const closingQuote = '`'

function formatNumber(value, locale, mathquill, opts = {}) {
  return isScientificNotation(value)
    ? formatScientificNotation(value, mathquill)
    : formatPlain(value, locale, opts)
}

function formatScientificNotation(value, mathquill) {
  if (!mathquill) return value
  const [mantissa, exponent] = parseScientificNotation(value)
  return `${mantissa}*10^{${exponent}}`
}

export function substituteVars(input, vars, locale) {
  return vars.reduce((text, v) => {
    const fractionDigits = v.value.toString().split('.')[1]
    const numFractionDigits = fractionDigits && fractionDigits.length
    return (
      text
        // Replace mathquill variables first so that we can apply special
        // formatting for numbers in scientific notation:
        .replace(
          new RegExp(
            // eslint-disable-next-line no-useless-escape
            `(\\\(.*?)${openingQuote}${escapeRegExp(v.name)}${closingQuote}(.*?\\\))`,
            'g',
          ),
          `$1${formatNumber(v.value, locale, true, {minimumFractionDigits: numFractionDigits})}$2`,
        )
        // Then substitute non-mathquill variables:
        .replace(
          new RegExp(`${openingQuote}${escapeRegExp(v.name)}${closingQuote}`, 'g'),
          formatNumber(v.value, locale, false, {
            minimumFractionDigits: numFractionDigits,
            useGrouping: true,
          }),
        )
    )
  }, input)
}

let promiseToGetMathjs
export const mathjsLoadingWrapper = {mathjs: null}
export const loadMathjs = function () {
  if (!promiseToGetMathjs) {
    promiseToGetMathjs = import(/* webpackChunkName: "mathjs" */ 'mathjs').then(_mathjs => {
      // import all our additional factory functions
      _mathjs.import(additionalFunctions, {override: true})
      _mathjs.config({angles: 'deg'})

      mathjsLoadingWrapper.mathjs = _mathjs
      return mathjsLoadingWrapper.mathjs
    })
  }

  return promiseToGetMathjs
}

export const mathjsIsLoaded = () => mathjsLoadingWrapper.mathjs !== null