Alex Shapalov alexshapalov

Most Ruby programmers don't have any idea how garbage collection works in their runtime - what triggers it, how often it runs, and what is garbage collected and what isn't. That's not entirely a bad thing - garbage collection in dynamic languages like Ruby is usually pretty complex, and Ruby programmers are better off just focusing on writing code that matters for their users.

But, occasionally, you get bitten by GC - either it's running too often or not enough, or your process is using tons of memory but you don't know why. Or maybe you're just curious about how GC works!

One way we can learn a bit about garbage collection in CRuby (that is, the standard Ruby runtime, written in C) is to look at the built-in GC module. If you haven't read the docs of this module, check it out. There's a lot of interesting methods in there. But for right now, we're just going to look at one: GC.stat.

GC.stat outputs a hash with a bunch of different numbers, but none of th

How to change your commit messages in Git?

At some point you’ll find yourself in a situation where you need edit a commit message. That commit might already be pushed or not, be the most recent or burried below 10 other commits, but fear not, git has your back 🙂.

Not pushed + most recent commit:

git commit --amend

This will open your $EDITOR and let you change the message. Continue with your usual git push origin master.

Disclaimer 1: Первую которая "про то чего мы достигли" я таки пропустил.

Disclaimer 2: Многие доклады смотрелись и отчёты писались в состоянии алкогольного опьянения.

1. Ben Alpert - What Lies Ahead

Сейчас посмотрел Ben Alpert - What Lies Ahead она про то какие идеи они имеют о дальнейшем развитии. И они делят на UX-идеи и DX-идеи. В UX у них:

It's important to note that running this reset will drop any existing data you have in the application

How to reset PG Database on Heroku?

Step 1: heroku restart
Step 2: heroku pg:reset DATABASE (no need to change the DATABASE)
Step 3: heroku run rake db:migrate
Step 4: heroku run rake db:seed (if you have seed)

One liner

Screen Quick Reference

Basic

Description	Command
Start a new session with session name	`screen -S <session_name>`
List running sessions / screens	`screen -ls`
Attach to a running session	`screen -x`
Attach to a running session with name	`screen -r`

Originally published in June 2008

When hiring Ruby on Rails programmers, knowing the right questions to ask during an interview was a real challenge for me at first. In 30 minutes or less, it's difficult to get a solid read on a candidate's skill set without looking at code they've previously written. And in the corporate/enterprise world, I often don't have access to their previous work.

To ensure we hired competent ruby developers at my last job, I created a list of 15 ruby questions -- a ruby measuring stick if you will -- to select the cream of the crop that walked through our doors.

What to expect

Candidates will typically give you a range of responses based on their experience and personality. So it's up to you to decide the correctness of their answer.

How Dev Bootcamp Teaches: ActiveRecord

I'm Jesse, one of the co-founders of Dev Bootcamp, and the acting curricular editor-in-chief. We get lots of questions about how Dev Bootcamp approaches teaching, what our curriculum is like, and how it differs from other schools and competitors. I thought I'd share some of that with you, starting with a brief overview of our theory of learning and then sharing our introduction to ActiveRecord.

This will be light on theory and heavy on ActiveRecord, so if you're not familiar with SQL or Ruby it might be hard to follow. Mea culpa.

Dev Bootcamp's Theory of Learning

At Dev Bootcamp, we believe that "modeling" is central to learning. The most effective students have a clear model of how the world works and are able to quickly integrate new information int

Capybara

save_and_open_page

Matchers

have_button(locator)

	# Example of refactoring long method.

	def self.get_troubled_reasons(where_cond, session_country)
	reasons = (1..18).map { \|e\| "TR#{e.to_s.rjust(3, '0')}" }
	query = reasons.map do \|reason\|
	"SUM(CASE WHEN reason_code LIKE '%#{reason}%' THEN 1 ELSE 0 END) AS #{reason}"
	end.join(',')

	TroubledOrder.joins(:order).select(query).where(orders: { country_code: session_country }).where(where_cond).first
	end

	heroku pg:reset SHARED_DATABASE --confirm fasterfaster
	heroku run rake db:migrate
	heroku run console
	Rails.cache.clear
	heroku restart
	- manually add one record to test
	- run performance test