MongoDB: how to find documents ignoring case sensitive, accents and percent like logic (%)

what happened if you use just :

find({name: {$regex: 'pala', $options: "i"}})

you used new Regex() that may not valid constructor valid constructor is new RegExp()

This works for me!

Just replace vowels with a regex which contains accents vowels. Additionally can use $options: 'i' to avoid case sensitive.

function diacriticSensitiveRegex(string = '') {
         return string.replace(/a/g, '[a,á,à,ä]')
            .replace(/e/g, '[e,é,ë]')
            .replace(/i/g, '[i,í,ï]')
            .replace(/o/g, '[o,ó,ö,ò]')
            .replace(/u/g, '[u,ü,ú,ù]');
    }

find ({ name: { $regex: diacriticSensitiveRegex('pala'), $options: 'i' } });

There is no magic bullet here inside of MongoDb. But since you obviously changing user input anyway to create '%pala%', why not replace "a" with "[aá]" and wrap in ".*", this way you can use regex and have your diacritics.

Here are options not much work to create replaces.

French Letters [a-zA-ZàâäôéèëêïîçùûüÿæœÀÂÄÔÉÈËÊÏΟÇÙÛÜÆŒ]

German Letters The controversial capital letter for ß, now included in unicode, is missing in many fonts, so it might show on your screen as a question mark. [a-zA-ZäöüßÄÖÜẞ]

Polish Letters [a-pr-uwy-zA-PR-UWY-ZąćęłńóśźżĄĆĘŁŃÓŚŹŻ] Note that there is no Q, V and X in Polish. But if you want to allow all English letters as well, use [a-zA-ZąćęłńóśźżĄĆĘŁŃÓŚŹŻ]

Italian Letters [a-zA-ZàèéìíîòóùúÀÈÉÌÍÎÒÓÙÚ]

Spanish Letters [a-zA-ZáéíñóúüÁÉÍÑÓÚÜ] from http://www.rexegg.com/regex-interesting-character-classes.html#languages