Nate Delage ndelage

Unix Command Line Fu

Basics

tab completion

Nearly all shells have support for tab completion. At a minimum for completing file & directory names, though some even tab-complete based on which commands you're running. Some examples:

$ ls [TAB]
Gemfile app/ connectors.rb public/

Unix Challenge

Background

In this challenge you'll become familiar with a number of standard Unix command utilities and then implement a subset of their functionality in Ruby. You'll gain a better understanding of:

files/descriptors in unix
pipes
sockets
STDIN, STDERR, STDOUT

Tips for a #WINNING Github Profile

The basics

As a new developer some potential employers are going to review your Github profile as part of the interview process. This doc covers some tips that should help you make a good impression. What this doc won't do is polish a turd.

README

Think of your experiences reviewing a Gem or other JS library on Github. Where do you look first? The README of course. What makes for a frustrating repo? One that doesn't:

include a README.
include install instructions (if applicable)

Managing Secret Data in Open source Applications

If you're working on an open source project, committing API keys or secrets to your repo is a big no-no. You wouldn't want anyone else making request with your keys, right?

So instead of putting those keys in app/config/initializers set then as environment variables in your shell. Here's an example for a Facebook API key:

export FB_API_KEY=3629346238763284623874623

Entrepreneurial Notes

I've begun taking detailed notes for the entrepruneral presentations, articles and books I find most valuable. For now, these notes live here as a collection of Gists.

Web Preformance

Sources of slow

Database

n+1 queries (try :includes or join)
Complex joins (is there another way to find the data?)
Missing indexes
Useless indexes
Schema (prossibly denormalize)

Continuous Integration for Fun and Profit

Continu-what?

Definition: the practice of frequently integrating one's new or changed code with the existing code repository -Wikipedia

Merging new code into master often sounds awesome, but we've been learning the value of testing and the importance of a passing test suite.

But, as your projects grow, your test suite should grow as well. We're all lazy and forget to run the entire test suite everytime we create a new commit. For large projects, running the entire test suite can take hours. So we do what all lazy people do, make a computer to the work for us.

Testing Tips & Tricks

Run a single test

In a large application, running all the tests at once using rake spec can make it difficult to check the output of the test you're working on. Especially if you have many failing or pending tests. Run a single test by running rspec:

rspec spec/models/account.rb

You can be even more specific and run a specific example from a test file. For example, given the following tests:

11: describe "#deposit!" do

Definitions

General Testing

TDD Test Driven Development. Write examples before implementation.
BDD Behaviour-Driven Development is about implementing an application by describing its behavior from the perspective of its stakeholders. (The Rspec Book)
RSpec (mention alternatives, write a simple hand sewn test)

	require 'lib/svm'

	data = [
	[5, {:year => 1987, :campy => 1}],
	[3, {:year => 1978, :man_eating_monsters => 1, :horror => 1}],
	[2, {:year => 1988, :teens => 1}]
	]

	predictor = SvmPrediction.from_svm_problem( data )
	puts predictor.predict(:year => 1988)