bradtraversy

MongoDB Cheat Sheet

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dferber90

Visual Regression Testing with Jest

This is a walkthrough of how to set up Visual Regression Testing with Jest for an application created with create-react-app.

The following walkthrough uses React as an example, but the approach should work for any modern frontend library! I assume it can be used with Angular, Vue, Cycle.js and more.

This gist walks you through a create-react-app application as an example of how to set up Visual Regression Testing in Jest using libraries I wrote recently which enable this: jsdom-screenshot, jest-transform-css and jest-transform-file.

steffencrespo

1-In the github repo on Settings > Integration & Services, enable
2-Go to travisCI page and enable the repo
3-Configure the env variables on TravisCI so that it is not necessary to save credentials on github
	-in the project Settings on TravisCI, add the entry for netlify site id: NETLIFY_SITE_ID - <site_id from .netlify file generated on netlify create>
	-create a netlify access token for TravisCI
		-On Netlify Dashboard, Go to Account Settings > OAuth Applications (https://app.netlify.com/account/applications) > Personal access tokens and press New Access Token
		-Name it anything, but to make it easier the suggestion is name TravisCI. 
		-Generate it and COPY it - you won’t see it again!
	-in the project Settings on TravisCI, add the entry for netlify personal access token generated for TravisCI: NETLIFY_ACCESS_TOKEN
4-Generate a .travis.yml file in the local repo

faressoft

DOM Performance

• How the browser renders the document
  • Receives the data (bytes) from the server.
  • Parses and converts into tokens (<, TagName, Attribute, AttributeValue, >).
  • Turns tokens into nodes.
  • Turns nodes into the DOM tree.
• Builds CSSOM tree from the css rules.

yangshun

	prettier-eslint	eslint-plugin-prettier	eslint-config-prettier
What it is	A JavaScript module exporting a single function.	An ESLint plugin.	An ESLint configuration.
What it does	Runs the code (string) through prettier then eslint --fix. The output is also a string.	Plugins usually contain implementations for additional rules that ESLint will check for. This plugin uses Prettier under the hood and will raise ESLint errors when your code differs from Prettier's expected output.	This config turns off formatting-related rules that might conflict with Prettier, allowing you to use Prettier with other ESLint configs like eslint-config-airbnb.
How to use it	Either calling the function in your code or via [prettier-eslint-cli](https://github.co

fokusferit

Shallow

Real unit test (isolation, no children render)

Simple shallow

Calls:

• constructor
• render

anthonyray

1. Connect to your EC2 instance
2. Install zsh : sudo apt-get update && sudo apt-get install zsh
3. Edit your passwd configuration file to tell which shell to use for user ubuntu : sudo vim /etc/passwd
4. Look for ubuntu user, and replace bin/bash by bin/zsh
5. Install OhMyZsh : sh -c "$(wget https://raw.githubusercontent.com/robbyrussell/oh-my-zsh/master/tools/install.sh -O -)"
6. Disconnect from your instance and reconnect it.

wojteklu

Code is clean if it can be understood easily – by everyone on the team. Clean code can be read and enhanced by a developer other than its original author. With understandability comes readability, changeability, extensibility and maintainability.

---

General rules

1. Follow standard conventions.
2. Keep it simple stupid. Simpler is always better. Reduce complexity as much as possible.
3. Boy scout rule. Leave the campground cleaner than you found it.
4. Always find root cause. Always look for the root cause of a problem.

Design rules

michaellihs

tmux Cheat Sheet

Table of Contents

• General Usage
• Shortcuts
• Commands
• Scripting tmux
• Configuring tmux

gaearon

// connect() is a function that injects Redux-related props into your component.
// You can inject data and callbacks that change that data by dispatching actions.
function connect(mapStateToProps, mapDispatchToProps) {
  // It lets us inject component as the last step so people can use it as a decorator.
  // Generally you don't need to worry about it.
  return function (WrappedComponent) {
    // It returns a component
    return class extends React.Component {
      render() {
        return (