Extract unicode hashtags from text

hashtags.js

'use strict';

const twitter = require('twitter-text');

function extractTags(text) {
    const tags = twitter.extractHashtagsWithIndices(text);
    let buffer = '';
    let i = 0;
    for (let t of tags) {
        buffer += text.substring(i, t.indices[0]);
        i = t.indices[1];
    }
    buffer += text.substr(i);
    return {
        tags: tags.map(t => t.hashtag),
        text: buffer.trim()
    };
}

function tag(texts, vars) {
    vars = vars || [];
    let buffer = '';
    for (let t of texts) {
        buffer += t;
        let v = vars.shift();
        if (v) buffer += v;
    }
    return extractTags(buffer);
}


console.log(tag`שלום עולם! #ברכה #באנאלית`);