ycmjason

// https://github.com/ycmjason/svg-to-img
const getImageDataURL = (image, type = 'png') => {
  // pre: image is loaded
  if (type === 'jpg') type = 'jpeg';
  const { width, height } = image;
  const canvas = document.createElement('canvas');
  const context = canvas.getContext('2d');
  canvas.width = width;
  canvas.height = height;

ycmjason

const MongoClient = require('mongodb').MongoClient;

const DB_NAME = 'mydb';
const MONGO_URL = process.env.MONGO_URL;

const dbPromise = MongoClient.connect(
  MONGO_URL,
  { useNewUrlParser: true },
).then(client => client.db(DB_NAME));

ycmjason

const MongoClient = require('mongodb').MongoClient;

const DB_NAME = 'mydb';
const MONGO_URL = process.env.MONGO_URL;

const dbPromise = MongoClient.connect(
  MONGO_URL,
  { useNewUrlParser: true },
).then(client => client.db(DB_NAME));

ycmjason

const crushOnce = (xs) => {
  if (xs.length < 3) return xs;
  let count = 0;
  
  for (const x of xs) {
    if (x !== xs[0]) break;
    count++;
  }

  if (count >= 3) {

ycmjason

const asyncStringReplace = async (str, regex, aReplacer) => {
  regex = new RegExp(regex, regex.flags + regex.flags.includes('g')? '': 'g');
  const replacedParts = [];
  let match;
  let i = 0;
  while ((match = regex.exec(str)) !== null) {
    // put non matching string
    replacedParts.push(str.slice(i, match.index));
    // call the async replacer function with the matched array spreaded
    replacedParts.push(aReplacer(...match));

ycmjason

// Usage:   @include transition(width, height 0.3s ease-in-out);
// Output:  -webkit-transition(width 0.2s, height 0.3s ease-in-out);
//          transition(width 0.2s, height 0.3s ease-in-out);
//
// Pass in any number of transitions
@mixin transition($transitions...) {
  $unfoldedTransitions: ();
  @each $transition in $transitions {
    $unfoldedTransitions: append($unfoldedTransitions, unfoldTransition($transition), comma);
  }

ycmjason

const objectAssignDeep = (...objs) => objs.reduce((acc, obj) => Object.assign(acc, ...Object.keys(obj).map(key => {
  if (acc[key] instanceof Object && obj[key] instanceof Object) {
    return { [key]: objectAssignDeep({}, acc[key], obj[key]) };
  }                                                                       
  return { [key]: obj[key] };
})));

ycmjason

// Simple memoization, done

const memoize = (fn) => {
  const memo = {};
  return function(...args){
    const hash = JSON.stringify(args);
    if(hash in memo) return memo[hash];
    return fn(...args);
  };
};

ycmjason

const limitAsyncCalls = (fn, n) => {
  const cap = n;
  let executing_count = 0;
  let waitings = [];

  const wait = () => new Promise(res => waitings.push(res));
  const execute = async (fn, args) => {
    executing_count++;
    const result = await fn(...args);
    executing_count--;

ycmjason

const queue = (() => {
  const promises = {};
  return async (name, f) => {
    while(promises[name]) await promises[name];
    promises[name] = f();
    const res = await promises[name];
    promises[name] = undefined;
    return res;
  };
})();