Anderkins

Gettings started writing a ESLint rule

First, take a look at the ESLint rule documentation. Just skim it for now. It's very long and boring. You can come back to it later.

ESLint rules works on the AST (Abstract Syntax Tree) representation of the code. In short, this is a tree structure that describes the code in a very verbose form. ESLint walks this tree and rules can subscribe to be notified when it hits a specific node type, like a Literal type, which could be the "hello" part of const welcome = "hello";.

Go ahead and play around with some code in AST Explorer (Make sure the parser is espree). It's a great tool!

Here are some good articles on the subject (ignore the scaffolding parts):

https://insideops.wordpress.com/2015/12/08/creating-custom-rules-for-eslint/

Default

Powerlevel10k

Better local require() paths for Node.js

Problem

When the directory structure of your Node.js application (not library!) has some depth, you end up with a lot of annoying relative paths in your require calls like:

const Article = require('../../../../app/models/article');

Those suck for maintenance and they're ugly.

	# This makes sure Chrome is always up to date in your test suite
	# On average this adds about 10 seconds to your build suite
	# Be sure to use Ubuntu 14.04 (Trusty) in the CircleCI's OS setting (Settings > Build Environment)
	dependencies:
	pre:
	- curl -L -o google-chrome.deb https://dl.google.com/linux/direct/google-chrome-stable_current_amd64.deb
	- sudo dpkg -i google-chrome.deb
	- sudo sed -i 's\|HERE/chrome\"\|HERE/chrome\" --disable-setuid-sandbox\|g' /opt/google/chrome/google-chrome
	- rm google-chrome.deb

	var fn = function(arg1, arg2) {
	var str = '<p>aap ' + this.noot + ' ' + arg1 + ' ' + arg2 + '</p>';
	document.body.innerHTML += str;
	};
	var context = {
	'noot': 'noot'
	};
	var args = ['mies', 'wim'];

	// Calls a function with a given 'this' value and arguments provided individually.