pulsar/spec/helpers/random.js

const WORDS = require('./words')
const {Point, Range} = require('text-buffer')

exports.getRandomBufferRange = function getRandomBufferRange (random, buffer) {
  const endRow = random(buffer.getLineCount())
  const startRow = random.intBetween(0, endRow)
  const startColumn = random(buffer.lineForRow(startRow).length + 1)
  const endColumn = random(buffer.lineForRow(endRow).length + 1)
  return Range(Point(startRow, startColumn), Point(endRow, endColumn))
}

exports.buildRandomLines = function buildRandomLines (random, maxLines) {
  const lines = []

  for (let i = 0; i < random(maxLines); i++) {
    lines.push(buildRandomLine(random))
  }

  return lines.join('\n')
}

function buildRandomLine (random) {
  const line = []

  for (let i = 0; i < random(5); i++) {
    const n = random(10)

    if (n < 2) {
      line.push('\t')
    } else if (n < 4) {
      line.push(' ')
    } else {
      if (line.length > 0 && !/\s/.test(line[line.length - 1])) {
        line.push(' ')
      }

      line.push(WORDS[random(WORDS.length)])
    }
  }

  return line.join('')
}