Stephen Margheim fractaledmind

FWIW: I (@rondy) am not the creator of the content shared here, which is an excerpt from Edmond Lau's book. I simply copied and pasted it from another location and saved it as a personal note, before it gained popularity on news.ycombinator.com. Unfortunately, I cannot recall the exact origin of the original source, nor was I able to find the author's name, so I am can't provide the appropriate credits.

Effective Engineer - Notes

By Edmond Lau
Highly Recommended 👍
http://www.theeffectiveengineer.com/

What's an Effective Engineer?

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

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

Design rules

Upload a file in Rails, parse it, then throw it away

You don't need Paperclip or Carrierwave or even an ActiveRecord model to manage file uploads in Rails if all you need to do is read the file in and extract data from it.

The Catalog class (referenced in the UploadController#create method) knows how to read a JSON file, translate and extract the data therein, and create or modify Book and Product records in the surrounding application.

By using the FileUtils.cp class method, we move the uploaded file into a known location at a known filename, so the Catalog (PORO) can do its work. The tempfile created by Rack during the upload is harvested as normal by garbage collection, but the copy we made is deleted manually after the parsing process is completed.

	//----------------------------------*\
	// TRIGONOMETRY FUNCTIONS
	//----------------------------------*/

	// # Trigonometry in CSS
	//
	// - Through Taylor/Maclaurin polynomial representation: http://people.math.sc.edu/girardi/m142/handouts/10sTaylorPolySeries.pdf
	// - Useful if you don't want to use JS.
	// - With CSS Variables.
	// - `calc()` can't do power (x ^ y) so I used multiplication instead.

	// UPDATE: In 2023, you should probably stop using this! The narrow version of Safari that
	// does not support `nomodule` is probably not being used anywhere. The code below is left
	// for posterity.

	/**
	* Safari 10.1 supports modules, but does not support the `nomodule` attribute - it will
	* load <script nomodule> anyway. This snippet solve this problem, but only for script
	* tags that load external code, e.g.: <script nomodule src="nomodule.js"></script>
	*
	* Again: this will not prevent inline script, e.g.:

	gem 'devise'

	# ENV variable management
	gem 'figaro'

	# OmniAuth Authentication providers
	gem 'omniauth-google-oauth2'
	gem 'omniauth-facebook'

	group :development, :test do

	require 'monitor'

	class IdWorker

	attr_reader :worker_id, :datacenter_id, :reporter, :logger, :sequence, :last_timestamp

	TWEPOCH = 1288834974657
	WORKER_ID_BITS = 5
	DATACENTER_ID_BITS = 5
	MAX_WORKER_ID = (1 << WORKER_ID_BITS) - 1

	{
	"keys": ["tab"],
	"command": "expand_abbreviation_by_tab",

	// put comma-separated syntax selectors for which
	// you want to expandEmmet abbreviations into "operand" key
	// instead of SCOPE_SELECTOR.
	// Examples: source.js, text.html - source
	"context": [
	{

	# this is a dirty implementation of logger that
	# compiles AR queries with trace into /last_request_log.html
	# the snippet is useful when optimizing performance of the endpoint

	class QueryLogSubscriber < ActiveSupport::LogSubscriber
	TRACE_LEVEL = :app
	LINES = 5
	IGNORE_CACHED_QUERIES = false

	def initialize

	function mapValues(obj, fn) {
	return Object.keys(obj).reduce((result, key) => {
	result[key] = fn(obj[key], key);
	return result;
	}, {});
	}

	function pick(obj, fn) {
	return Object.keys(obj).reduce((result, key) => {
	if (fn(obj[key])) {