semver/internal/identifiers.js

The semantic version parser used by npm.

'use strict'

const numeric = /^[0-9]+$/
const compareIdentifiers = (a, b) => {
  if (typeof a === 'number' && typeof b === 'number') {
    return a === b ? 0 : a < b ? -1 : 1
  }

  const anum = numeric.test(a)
  const bnum = numeric.test(b)

  if (anum && bnum) {
    a = +a
    b = +b
  }

  return a === b ? 0
    : (anum && !bnum) ? -1
    : (bnum && !anum) ? 1
    : a < b ? -1
    : 1
}

const rcompareIdentifiers = (a, b) => compareIdentifiers(b, a)

module.exports = {
  compareIdentifiers,
  rcompareIdentifiers,
}