sql.js

'use strict'

let sqlstring = require('sqlstring');

class SQLUnsafe {
  constructor(sql) {
    this.sql = sql;
  }
}

class SQLQuery {
  constructor(strings, values) {
    this.strings = strings
    this.values = values
  }

  toQuery(values=[]) {
    let text = this.strings[0];
    for (let i = 0; i<this.strings.length-1; i++) {
      let s = this.strings[i + 1];
      let v = this.values[i];
      if (v instanceof SQLUnsafe) {
        text += v.sql;
      } else if (v instanceof SQLQuery) {
        let built = v.toQuery(values);
        text += built.text;
      } else {
        values.push(v);
        text += `?`;
      }
      text += s;
    }
    return {text, values};
  }

  toSql() {
    let {text, values} = this.toQuery();
    return sqlstring.format(text, values);
  }
}

function q(strings) {
  return new SQLQuery(
    strings.slice(0),
    Array.from(arguments).slice(1))
}

/** Escape identifier. */
function id(name) {
  return UNSAFE(sqlstring.escapeId(name));
}

/** Inject UNSAFE SQL string. */
function UNSAFE(sql) {
  return new SQLUnsafe(sql);
}

module.exports = {q, UNSAFE, id};