In Javascript, what's an efficient way to replace adjacent duplicate phrases in a random string?

I’d like to replace duplicate phrases that appear adjacent to the original phrase in a string.
None of the phrases or strings are known at runtime.

I’ve tried some regex that I think should work, to replace the duplicate phrase with " | ". See below.

Example Input String:

"FounderFounder Breakthrough Energy Breakthrough Energy 2015 - Present · 8 yrs2015 - Present · 8 yrs"

Desired Output String

"Founder | Breakthrough Energy | 2015 - Present · 8 yrs |"

// Regex function
function replaceDuplicateSubstrings(string) {
    var regex = /(\b\w+\b)\s+\1/g;
    return string.replace(regex, "$1 |");
}
// Sample String
var exampleString = "FounderFounder Breakthrough Energy Breakthrough Energy 2015 - Present · 8 yrs2015 - Present · 8 yrs";

// Console Write
console.log(replaceDuplicateSubstrings(exampleString)); 


// Should log "Founder | Breakthrough Energy | 2015 - Present · 8 yrs |" to the console
// Instead logs the same input string with no changes: "FounderFounder Breakthrough Energy Breakthrough Energy 2015 - Present · 8 yrs2015 - Present · 8 yrs"
`

>Solution :

You may use this snippet:

const str = "FounderFounder Breakthrough Energy Breakthrough Energy 2015 - Present · 8 yrs2015 - Present · 8 yrs";
var repl = str.replace(/(.+?)\1/g, "$1 |");

console.log(repl)

RegEx Demo

RegEx Pattern (.+?)\1 matches 1+ of any characters and captures it in group #1. It must be immediately followed by back-reference \1 to make sure adjacent repeating text.