SQL template tag

sql.js

'use strict'

/**
 * Maps the given value to a value expressible in SQL.
 * @param {*} val
 * @return {String}
 */
function sqlValue(val) {
  if (val === null) return null
  if (val === "'null'") return 'null'
  if (val === 'null') return 'null'
  if (typeof val === 'undefined') return 'null'
  if (typeof val === 'number') return val
  if (typeof val === 'string') return `'${val}'`
  if (typeof val === 'object') return `'${JSON.stringify(val)}'`
  return val.toString()
}

/**
 * Template tag function for creating SQL statements.
 * @param {String[]} strings
 * @param {...*} values
 * @return {String}
 */
module.exports = function(strings, ...values) {
  let output = ''
  strings.forEach((str, i) => {
    if (i >= values.length) output += str
    else output += str + sqlValue(values[i] || null)
  })
  return output
}