encodeURI()

const uri = "https://mozilla.org/?x=";
const encoded = encodeURI(uri);
console.log(encoded);
// : "https://mozilla.org/?x=%D1%88%D0%B5%D0%BB%D0%BB%D1%8B"

try {
  console.log(decodeURI(encoded));
  // : "https://mozilla.org/?x="
} catch (e) {
  // Catches a malformed URI
  console.error(e);
}

encodeURI(uri)

http://username:password@www.example.com:80/path/to/file.php?foo=316&bar=this+has+spaces#anchor

const name = "Ben & Jerry's";

// This is bad:
const link = encodeURI(`https://example.com/?choice=${name}`); // "https://example.com/?choice=Ben%20&%20Jerry's"
console.log([...new URL(link).searchParams]); // [['choice', 'Ben '], [" Jerry's", '']

// Instead:
const link = encodeURI(
  `https://example.com/?choice=${encodeURIComponent(name)}`,
);
// "https://example.com/?choice=Ben%2520%2526%2520Jerry's"
console.log([...new URL(link).searchParams]); // [['choice', "Ben%20%26%20Jerry's"]]

const set1 = ";/?:@&=+$,#"; // 
const set2 = "-.!~*'()"; // 
const set3 = "ABC abc 123"; //  + 

console.log(encodeURI(set1)); // ;/?:@&=+$,#
console.log(encodeURI(set2)); // -.!~*'()
console.log(encodeURI(set3)); // ABC%20abc%20123 ( %20 )

console.log(encodeURIComponent(set1)); // %3B%2C%2F%3F%3A%40%26%3D%2B%24%23
console.log(encodeURIComponent(set2)); // -.!~*'()
console.log(encodeURIComponent(set3)); // ABC%20abc%20123 ( %20 )

//  OK
console.log(encodeURI("\uD800\uDFFF"));

//  "URIError: malformed URI sequence" 
console.log(encodeURI("\uD800"));

//  "URIError: malformed URI sequence" 
console.log(encodeURI("\uDFFF"));

function encodeRFC3986URI(str) {
  return encodeURI(str)
    .replace(/%5B/g, "[")
    .replace(/%5D/g, "]")
    .replace(
      /[!'()*]/g,
      (c) => `%${c.charCodeAt(0).toString(16).toUpperCase()}`,
    );
}