How do I swap substrings within a string?

Question

I am trying to swap all occurrences of a pair of substrings within a given string.

For example, I may want to replace all occurrences of \"coffee\" with \"tea\" and

Answer 1

Based on @alexander-gessler's answer, but with support for dynamic inputs.

(While potentially opening the door to code injection.)

function swapSubstrings(string, a, b) {
  return string.replace(
    new RegExp(`(${a}|${b})`, "g"),
    match => match === a ? b : a
  )
}