ef4

Webpack 5 Node Polyfills Upgrade Cheatsheet

Webpack 4 automatically polyfilled many Node APIs in the browser. This was not a great system, because it could lead to surprisingly giant libraries getting pulled into your app by accident, and it gave you no control over the exact versions of the polyfills you were using.

So Webpack 5 removed this functionality. That means you need to make changes if you were relying on those polyfills. This is a quick reference for how to replace the most common patterns.

List of polyfill packages that were used in webpack 4

For each automatically-polyfilled node package name on the left, this shows the name of the NPM package that was used to polyfill it on the right. Under webpack 5 you can manually install these packages and use them via resolve.fallback.

slikts

Advanced memoization and effects in React

Memoization is a somewhat fraught topic in the React world, meaning that it's easy to go wrong with it, for example, by [making memo() do nothing][memo-pitfall] by passing in children to a component. The general advice is to avoid memoization until the profiler tells you to optimize, but not all use cases are general, and even in the general use case you can find tricky nuances.

Discussing this topic requires some groundwork about the technical terms, and I'm placing these in once place so that it's easy to skim and skip over:

• Memoization means caching the output based on the input; in the case of functions, it means caching the return value based on the arguments.
• Values and references are unfortunately overloaded terms that can refer to the low-level implementation details of assignments in a language like C++, for example, or to memory

ryanflorence

Everything I Know About UI Routing

Definitions

1. Location - The location of the application. Usually just a URL, but the location can contain multiple pieces of information that can be used by an app
   1. pathname - The "file/directory" portion of the URL, like invoices/123
   2. search - The stuff after ? in a URL like /assignments?showGrades=1.
   3. query - A parsed version of search, usually an object but not a standard browser feature.
   4. hash - The # portion of the URL. This is not available to servers in request.url so its client only. By default it means which part of the page the user should be scrolled to, but developers use it for various things.
   5. state - Object associated with a location. Think of it like a hidden URL query. It's state you want to keep with a specific location, but you don't want it to be visible in the URL.

gaearon

Note:

When this guide is more complete, the plan is to move it into Prepack documentation.
For now I put it out as a gist to gather initial feedback.

A Gentle Introduction to Prepack (Part 1)

If you're building JavaScript apps, you might already be familiar with some tools that compile JavaScript code to equivalent JavaScript code:

• Babel lets you use newer JavaScript language features, and outputs equivalent code that targets older JavaScript engines.

Kruemelkatze

Theming Ant Design with Sass and Webpack

This is a solution on how to theme/customize Ant Design (which is written in Less) with Sass and webpack. Ant itself offers two solutions and a related article on theming, but these are only applicable if you use Less, the antd-init boilerplate or dva-cli.

What this solution offers:

• use a single sass-file to customize (no duplicate variables for your project and Ant)
• hot reload compatibility
• no dependencies on outdated npm modules
• easy integration with your existing webpack setup (webpack 3+ tested)

j1r1k

const R = require("ramda");

const data = {
  title: "Intro to functional lenses",

  author: {
    name: "Jiri Marsicek",
    email: "jiri.marsicek@gmail.com",
    position: {
      name: "Software Engineer",

ximeg

#!/usr/bin/env python
# Implementation of algorithm from http://stackoverflow.com/a/22640362/6029703
import numpy as np
import pylab

def thresholding_algo(y, lag, threshold, influence):
    signals = np.zeros(len(y))
    filteredY = np.array(y)
    avgFilter = [0]*len(y)
    stdFilter = [0]*len(y)

MoOx

# ...

[options]
# webpack loaders
module.name_mapper='.*\.css$' -> '<PROJECT_ROOT>/flow/stub/css-modules.js'
module.name_mapper='.*\.\(svg\|png\|jpg\|gif\)$' -> '<PROJECT_ROOT>/flow/stub/url-loader.js'

mpj

Usage

node dirtyserve.js

The point your browser to

http://localhost:3000/myfile.xxx

and the server will try to serve that file from the local server.

subfuzion

Common Options

-#, --progress-bar Make curl display a simple progress bar instead of the more informational standard meter.

-b, --cookie <name=data> Supply cookie with request. If no =, then specifies the cookie file to use (see -c).

-c, --cookie-jar <file name> File to save response cookies to.