Parse basic bash brace expansions. Demo: https://jsfiddle.net/ccnokes/kdqm5o7f/. Just because. I should learn how to write a compiler/interpreter thing for real.

parse-bash-brace-expansion.js

// Test it...
console.log(
  expandBraces('test-{a,b,c}-test')
);
/* test-a-test test-b-test test-c-test */


function expandBraces(str) {
  let { preamble, expressionList, postscript } = parse(str);
  return expressionList
    .map(str => `${preamble}${str}${postscript}`)
   .join(' ')
}

function parse(str) {
  let openingBrace = str.match(/{/);
  let closingBrace = str.match(/}/);
  if (!openingBrace || !closingBrace) {
    throw new Error('Must pass an opening/closing brace');
  }
  let preamble = str.slice(0, openingBrace.index);
  let postscript = str.slice(closingBrace.index + 1, str.length);
  let expressionRaw = str.slice(openingBrace.index + 1, closingBrace.index);
  let expressionList = expressionRaw.split(',');
  if (expressionList.length === 0) {
    throw new Error('Must pass at least one item in the expression list');
  }
  return { preamble, expressionList, postscript };
}