Thúlio Costa thulio

My notes on the video series "London vs Chicago TDD styles" by Uncle Bob And Sandro Mancuso

The git repo of the kata is here: https://github.com/sandromancuso/cleancoders_openchat/

The "starting-point" branch is where both implementations began: https://github.com/sandromancuso/cleancoders_openchat/tree/starting-point

The 🇬🇧 "openchat-outside-in" branch captures the tomato by tomato history of the London approach.
The 🇺🇸 "openchat-unclebob" branch captures the tomato by tomato history of the Chicago approach.

What I like about Sandro's style 👍

Atom Clojure Setup

This describes how I setup Atom for an ideal Clojure development workflow. This fixes indentation on newlines, handles parentheses, etc. The keybinding settings for enter (in keymap.cson) are important to get proper newlines with indentation at the right level. There are other helpers in init.coffee and keymap.cson that are useful for cutting, copying, pasting, deleting, and indenting Lisp expressions.

Install Atom

Download Atom

The Atom documentation is excellent. It's highly worth reading the flight manual.

Demonstrate Erlang's 'busy wait' effect on CPU utilization

How?

Just make Erlang to do some light-load task in a bunch of relatively short leaving processes. Calculating PI to 80th digit in batches per 10 procs with short, 8 ms, sleep in-between, to give schedulers a breath space, will do.

Running

Run erl with 8 schedulers and no busy waiting on schedulers at all.

	#!/bin/bash

	CONFIG_PATH=~/.config/Code

	for i in $CONFIG_PATH/User/workspaceStorage/*; do
	if [ -f $i/workspace.json ]; then
	folder="$(python3 -c "import sys, json; print(json.load(open(sys.argv[1], 'r'))['folder'])" $i/workspace.json 2>/dev/null \| sed 's#^file://##;s/+/ /g;s/%\(..\)/\\x\1/g;')"

	if [ -n "$folder" ] && [ ! -d "$folder" ]; then
	echo "Removing workspace $(basename $i) for deleted folder $folder of size $(du -sh $i\|cut -f1)"

	(function (context, trackingId, options) {
	const history = context.history;
	const doc = document;
	const nav = navigator \|\| {};
	const storage = localStorage;
	const encode = encodeURIComponent;
	const pushState = history.pushState;
	const typeException = 'exception';
	const generateId = () => Math.random().toString(36);
	const getId = () => {

	{_, port} = \
	GenServer.whereis(EventStore.Notifications.Listener.Postgrex)\
	\|> :sys.get_state()\
	\|> Map.get(:pid)\
	\|> :sys.get_state()\
	\|> Map.get(:mod_state)\
	\|> Map.get(:protocol)\
	\|> Map.get(:sock)

	:erlang.port_close(port)

	#! /usr/bin/env ruby

	# NOTE: Requires Ruby 2.1 or greater.

	# This script can be used to parse and dump the information from
	# the 'html/contact_info.htm' file in a Facebook user data ZIP download.
	#
	# It prints all cell phone call + SMS message + MMS records, plus a summary of each.
	#
	# It also dumps all of the records into CSV files inside a 'CSV' folder, that is created

	#!/bin/bash
	# This script provides easy way to debug remote Erlang nodes that is running in a kubernetes cluster.
	# Usage: ./erl-observe.sh -l app=my_all -n default -c erlang_cookie
	#
	# Don't forget to include `:runtime_tools` in your mix.exs application dependencies.
	set -e

	# Trap exit so we can try to kill proxies that has stuck in background
	function cleanup {
	echo " - Stopping kubectl proxy."

	CREATE TABLE accounts(
	id serial PRIMARY KEY,
	name VARCHAR(256) NOT NULL
	);

	CREATE TABLE entries(
	id serial PRIMARY KEY,
	description VARCHAR(1024) NOT NULL,
	amount NUMERIC(20, 2) NOT NULL CHECK (amount > 0.0),
	-- Every entry is a credit to one account...

	(ns x.y
	(:use [plumbing.core]) ;; Just for the map-vals
	(:require [clojure.walk :refer [postwalk prewalk prewalk-demo postwalk-demo]]
	[clojure.core.match :refer [match]]
	[schema.utils :refer [named-error-explain validation-error-explain]]
	[schema.core :as s])
	(:import (schema.utils NamedError ValidationError)))

	;; Partially FROM:
	;; https://github.com/puppetlabs/clj-schema-tools