A fun riff on the CommonJS require function with an expression-like syntax via template-literal tagging.

include.js

'use strict';

/**
 * Example Usage:
 *
 *     const b = 'b';
 *     const r = 'r';
 *     const foo = include `${b}a${r}`;
 */
module.exports = function include(strings, ...expressions) {
  const ref = expressions.reduce((out, expr, idx) => {
    return `${out}${expr}${strings[idx + 1]}`;
  });

  return require(ref);
};