Extreme Programming

Stimulus.js Lifecycle Callbacks

One common mistake I see in Stimulus controllers is that people use the connect() callback to set up…

My RuboCop config

By far my favorite is Style/MethodCallWithArgsParentheses, which forces parentheses everywhere. Optional parens are one of my least…

Enumerable in Go Using Generics

The latest iteration of generics is amazing. Here’s a short proof of concept for a Ruby-like enumerable construct.

package main

import (
 "fmt"
 "strings"
)

func newSliceEnum[T comparable](s []T)…

Avoid []

It’s a Risky Tool with No Benefit

What

Avoid calling hash[key]. Instead use hash.fetch(key) if the key is expected to always be present, or hash.fetch(key, nil) if it’s valid/expected for the key to be absent.

Why

Avoid #each_with_object (generally)

In my experience, Ruby’s each_with_object (docs here) can almost always be replaced with a simpler more specific/semantic construct.

Example 1

all_points = routes.each_with_object([]) do |route, result|…

Use buildpacks not Dockerfiles

Don’t take my word for it, let these people make the case.

https://www.youtube.com/watch?v=spW9ZlJpobM

https://blog.heroku.com/docker-images-with-buildpacks

https://www.youtube.com/watch?v=2Xorbt3TaP4

https://buildpacks.io/

Don’t use version constraints in Gemfile

The “~>” is not a “min version specifier”. It is the pessimistic operator. For example:

Don’t use version constraints outside of lock files

The coin change probem in Go

How many ways can we pick a set of coins of allowed denomination to equal a specified amount?

package main

import (
    "fmt"
)

func numWays(amount int, coins []int) (result int) {
    if amount == 0 {…

Details Matter

When you’re a disciplined software engineer, particularly one working in the XP (Extreme Programming) school, it can be a bit challenging when people don’t readily see the importance of minute details. But I find that people tend to care once they’ve been burned. This is one of my experiences sharing…

Avoiding Type Assertions in Go

Prefer Polymorphism to Conditionals

OOP vs. FP

I’ve come across countless articles debating the merits of object oriented programming (OOP) vs. functional programming (FP). I want to put a stop to this madness by simply noting that OOP and FP are only different in terms of minor semantics. For example, compare these two ways of writing the same code.

OAuth and TDD in Go

I recently set up some Go code to communicate with the Nielsen API using OAuth 2. In addition I wanted to use the VCR…

Exceptional Go

You’ll often hear Go developers claiming that it’s incorrect (not idiomatic) to panic in Go; instead we should return errors. After…

Tests & Dependencies

You’re probably mocking too much.

What Goes In Active Records

In October 2011, Gary Bernhardt did a two-part screencast titled “What Goes In Active Records” (1, 2). Starting with general principles, Gary states his goals for an ActiveRecord class’s design.

The things I want in this class are things that wrap the…

Unnecessary Conditionals

Imagine we have the following methods:

def book_content(indifferent)
  if indifferent
    book_json_blob_content_with_indifferent_access
  else
    book_json_blob_content
  end
end

def book_json_blob_content_with_indifferent_access…

Notes & Thoughts on Exceptional Ruby

Buy it here.

Bi-directional use of class_name in ActiveRecord associations

Labels: rails, ruby, software

I recently wanted to use ActiveRecord’s association syntax on two models, called Proposal and Period. To add clarity, I wanted the Proposals to be called…

What goes in Rails lib/

A common question teams run into while building a Rails app is “What code should go in the lib/ directory?”. The generated Rails README proclaims:

lib — Application specific libraries. Basically, any kind of custom code that doesn’t belong under controllers…

Ruby/Rails FYI

Interpolation

Interpolation automatically calls to_s, so the to_s calls in this sample text are unnecessary.

def s3_filename(record)
  name = record.name || 'Empty '
  date = Date.today.to_s
  guid = UUIDTools::UUID.random_create.to_s…

The Twelve-Factor App, Abridged

Use declarative formats.

• API (“clean contract”) with the OS for portability
• Cloud deployable
• Minimize divergence between dev and prod, facilitate continuous integration (CI).

The Hierarchy of Complexity for Conditionals

When the Ruby on Rails framework was first released, one of its biggest selling points was convention over configuration. Name your ActiveRecord model User, and it would use the users table in its generated SQL. This preempted the need for verbose…

Notes from 99 Bottles of OOP

Link to book.

The net cost of caching can be calculated only by comparing the benefit of increases in speed to the cost of creating and maintaining the cache. If you require this speed increase, any cost is cheap. If you don’t, every cost is too much.

On Comments

Documentation in code. Programmers are taught to comment their code: good code has lots of comments. Unfortunately, they are never taught why code needs comments: bad code requires lots of comments. The DRY principle tells us to keep the low-level knowledge in the code, where it belongs, and reserve the…