--description--

Given a string, return a URL-friendly version of the string using the following constraints:

• All letters should be lowercase.
• All characters that are not letters, numbers, or spaces should be removed.
• All spaces should be replaced with the URL-encoded space code %20.
• Consecutive spaces should be replaced with a single %20.
• The returned string should not have leading or trailing %20.

--hints--

generateSlug("helloWorld") should return "helloworld".

assert.equal(generateSlug("helloWorld"), "helloworld");

generateSlug("hello world!") should return "hello%20world".

assert.equal(generateSlug("hello world!"), "hello%20world");

generateSlug(" hello-world ") should return "helloworld".

assert.equal(generateSlug(" hello-world "), "helloworld");

generateSlug("hello world") should return "hello%20world".

assert.equal(generateSlug("hello  world"), "hello%20world");

generateSlug(" ?H^3-1*1]0! W[0%R#1]D ") should return "h3110%20w0r1d".

assert.equal(generateSlug("  ?H^3-1*1]0! W[0%R#1]D  "), "h3110%20w0r1d");

--seed--

--seed-contents--

function generateSlug(str) {

  return str;
}

--solutions--

function generateSlug(str) {
  let cleaned = str.replace(/[^a-zA-Z0-9 ]+/g, "");
  cleaned = cleaned.replace(/\s+/g, " ").trim();
  return cleaned.toLowerCase().replace(/ /g, "%20");
}