Travis Fantina

This week I formally transitioned from my fulltime consulting gig at Objective for a fulltime gig at Built For Teams more details on that in a future post. However; broadly speaking it means that I’m dusting off my Ruby skills, diving deeper into the realm of OO programing then I ever have before.

Farewell ASDF

Last Friday night I pulled a Flutter repo I’m working on with a friend. I started having all kinds of issues trying to install Cocoapods. gem install cocoapods but then flutter run produced this error:

Warning: CocoaPods is installed but broken. Skipping pod install.
...
Error: CocoaPods not installed or not in valid state.

Ok. So do some more research throw in a sudo, no luck. pod version produces this error:

<internal:/Users/travis/.asdf/installs/ruby/3.3.5/lib/ruby/3.3.0/rubygems/core_ext/kernel_require.rb>:136:in `require': linked to incompatible /Users/travis/.asdf/installs/ruby/3.1.6/lib/libruby.3.1.dylib -

Ah! I’ve seen this more than once! Ever since I shifted to a Ruby focused team at the start of the year I feel like Ruby version management has been an uphill slog. I’ve reshim’d multiple times, removed versions of Ruby, removed the Ruby plugin, and reinstalled ASDF. Things work for a time but eventually I run into errors like the above. My hunch, which may be ovbious, is that something was wrong with my setup that was placing versions of Ruby inside other versions (ruby/3.3.5/lib/ruby/3.3.0); I’m not sure if the path is supposed to look like that but it doesn’t make sensee to me. I’m willing to take responsability here, it may be that my $PATH was misconfigured (although I attempted multiple times to proide a concise path for ASDF) or that something in my system was messing with ASDF. I love ASDF, it’s served me very well for years. Being able to remove rvm and nvm and seamlessly manage Elixir versions between projects was a breath of fresh air. The docs are clear and concise, the tool provides enough functionality to get stuff done without getting in the way. However; for whatever reason, the slog to get Ruby working just took its toll. One of my coworkers mentioned Mise which is a drop in replacement for ASDF. I installed it in about 30 seconds and in 45 seconds my project was running with Mise. 👏

At the agency, we have a customer who has asked that customers accept terms of service before checking out. This is for an Elixir project; mostly fullstack Elixir however the frontend has an odd assortment of sprinkles: StimulusJS and React. I created a terms_and_conditions versions table and an accompanying view helper which will check a terms_version_accepted on the user record if the last terms_and_conditions.inserted_at date matches the terms_version_accepted then the user is shown an active “proceed to checkout” button, if not the button is disabled and a note asking them to acccept the terms of service will display.
Since most of the Elixir projects I work on are fullstack (Phoenix LiveView) I don’t often get to write API endpoints. The API work on this was admittidly very small, a simpl endpoint that takes the user’s ID and updates the terms_version_accepted timestamp when they click “accept” in the modal. It returns a URL which we then append to checkout link allowing the user to proceed. This feature is due May 5th but I’m hoping to get onto the staging server on Monday or Tuesday.

Internal Tooling:

I’ve been using fzf for a while but I’ve wanted to filter only unstaged files, ideally whenever I type git add I just want to see a list of unstaged files that I can add. Admittidly I got some help from AI to do write this up:

function git_add_unstaged() {
    local files
    files=$(git diff --name-only --diff-filter=ACMR | fzf --multi --preview 'git diff --color=always -- {}')
    if [[ -n "$files" ]]; then
        BUFFER="git add $files"
        CURSOR=$#BUFFER
    fi
}

function git_add_unstaged_widget() {
    if [[ $BUFFER == 'git add' ]] && [[ $CURSOR -eq $#BUFFER ]]; then 
        git_add_unstaged 
        zle redisplay
    else 
        zle self-insert
    fi
}

zle -N git_add_unstaged_widget 
bindkey ' ' git_add_unstaged_widget

I’m wondering if I’ll find the automatic git add to be jarring or have situations such as a merge conflict where this may not work. If so I can always fiddle with the bindkey but for right now I’m enjoying my new found git add speeds.

A phenomenal read, I was thoroughly hooked into this book from 1849 to 2346. I haven’t read anything quite like this; in the hands of a less talented writer, structurally, it could have been a bit gimmicky. However; Mitchell is talented provide one compelling story after another. Initially I worried that The Pacific Journal of Adam Ewing and Sloosha’s Crossin' an' Evrythin' After were going to drag because of the verbosity or eccentricity (respectively) of the language but after a few pages I was engrossed in both.

Working for a small agency I am fortunate to work on a number of fast moving projects simultaneously. For years I’ve failed to document what I do during the week but I’m going a little recap of my week. One part historical record, one part general interest. I’m posting it on my blog in the off chance that somebody reads it and, facing a similar problem will reach out I’m always happy to discuss what worked for me and what didn’t work. It also doesn’t hurt to put this stuff into the world to show that yes I actually do work; I haven’t always had the most active GitHub but most of my client projects a private/propriety. I’m easing into this, all week I was looking forward to this post; now, however, I realize I should have been working on this not cramming it in from memory on a Friday night.

This week was a balance between my ongoing Elixir projects and a newer (to me) Ruby project.

• For the past five years I’ve either supported, or been the lead dev on a large B2B ecommerce platform which handles a few million in daily sales. Over the winter the company began consolidating their North American and European processes which includes using said platform for sales in the EU. Although the hope is that the European process will align with the North American there are some relevant differences. For example in North America the client’s product is technically considered a “raw material” which means there is no “Value Added Tax” (VAT); however in Europe, depending on the country of origin and the destination VAT may be charged, other relevant changes are shipping across borders, truck loading calculations and different invoicing procedures. At this point we are still in the research and discovery phase but I’ve been working with another developer to scope this project out and write some preliminary tests as research.
• For another client I’ve been moving from a Quickbooks Online integration to Quickbooks Desktop, this is a multi-tenancy Elixir Phoenix app so I’ll be keeping the Online functionality and just adding a connection to Quickbooks Desktop. The API docs for QBOnline are fairly good, this is not the case with QB Desktop, it’s evident that Intuit either has the platform on life support or intentionally obfuscates the functionality to foster a consulting industry around the product. QB Desktop uses an SOAP XML type endpoint. Having wrangled fairly nasty endpoints with SAP I wanted to, if at all possible, avoid dealing directly with QB Desktop. I discovered a service called Conductor that does the bulk of the heavy lifting and allows you to hit a very concise REST endpoint.
• Since the beginning of the year I’ve been transitioning from primarily Elixir projects at the agency to a single Ruby based product. On that front I’ve been involved in an ongoing integration with BambooHR; partnering with Bamboo to pull employee data from their endpoint.
• On a personal front I finished the migration of this blog from Ghost back to markdown files. I still love Ghost but managing my own instance and integrating it with my Garden proved to be more management than I wanted.

Experience has shown that if you put out a bug bounty your server will be hit repeatedly with requests to /wp_admin for the rest of eternity.

I wrote this post back in January, just dusted it off to post today as I attempt to get back on the blogging horse.

Today I was refactoring a small module that makes calls to an SAP endpoint. The compiler got hung up because it couldn’t find the value item. It was an easy fix, my code looked like this:

for itm <- data do
    %{"MATNR" => material, "PSTYV" => category, "VBELN" => so} = item
    %{material: material, category: category, so: so}
end

It’s easy to spot (especially if the compiler tells you exactly where it is); in the function head I wrote itm but down below I’m looking for item. Simple; yet this is not the first time something similar has happened to me. It’s also not the first time I’ve specifically confused itm with item which led me to this conclusion: just write item every time. There is an odd switch in my brain that thinks I’m penalized by the character, and leaving e out of item will somehow make my code more terse. While technically true, it’s not worth it. It never is; just write item, everytime. People know what item is. itm is more ambiguous, not just because it only saves one letter, but it could be an abbreviation or some weird naming convention. Why put that mental load on someone, even yourself, reading through this code? This is a tiny example but it’s magnified in function names. While check_preq may be quick to type and take up less horizontal space in an editor it’s not immediately clear what this function does. I would argue that get_purchase_requisition_number is a much better function name; even if you know nothing about the function, the codebase, or programming in general you can read that and know what’s supposed to happen. Of course there are conventions, ie. ! dangerous or ? bankbook method endings in Ruby ie. exitst? will throw an error. These sorts of things require one to be a little familiar with the patterns of a language but that’s ok that just means that I can write a function get_purchase_requisition_number! and anyone familiar with Ruby or Elixir will expect the function to raise or return an explicit value (as opposed to something wrapped in an :ok tuple).

Moving forward I’m calling things what they are even if it comes with a dash of verbosity.

Reading 80% of this book was an exercise in torture. I’m always a little wary of personal memoirs cum self-help books but a few have been transformative for me (ie. Pamela Druckerman’s Bringing Up Bébé). Katherine May hooked me early with this book, the prose was sharp and the anecdotes interesting however it very quickly devolved into anecdote after anecdote from a brief period in her life where, I guess, she was forced to work less?

This book is rife with privilege, which doesn’t always bother me but in this particular case it seems to hallow where half of of the book is dedicated to the message of “slow down, take it easy” and the other half is, “go to Iceland, trek the northern tundras of Sweden”.

Ultimately this book fell into the same trap as Gretchen Rubin’s Happier At Home (a did not finish from last year); an extremely self absorbed upper-middle class person thinking that their experience = wisdom and is therefore worth writing an entire book.

Zero stars. Did not finish.

Today’s TIL has a twist ending… so stick around.

Elixir has a shortcut for creating anonymous functions. I’ve always written:

greet = fn name -> "Hello, #{name}!" end 
# which can be invoked
greet.("Travis")
# returns
"Hello, Travis!"

However; I came across some tricky code with a case statement:

docs = case type do 
	:billing -> &[billing_act: &1]
    :shipping -> &[shipping_act: &1]
end 

# invocation
type = :billing
docs.("some customer")
# returns 
[billing_act: "some customer"]

This was very confusing to me, the fact that the anonymous function was a case form only further obfuscated what was happening. I thought it might be some case magic.

No. Apparently you can short cut the aforementioned anonymous function declaration:

greet = & "Hello, #{&1}!"

You treat this as any other anonymous function. You can even have multi-arity functions:

greet = & "Hello, #{&1} #{&2}!"
# invocation 
greet.("Travis", "Fantina")
# returns 
"Hello, Travis Fantina!"

In my case the case statement could have also been written:

docs = fn customer -> 
	case type do
		:billing -> [billing_act: customer]
    	:shipping -> [shipping_act: customer]
	end
end

Plot twist: This is not a TIL, apparently I learned this at least four years ago. That initial case function… the author was me four years ago!

Interesting things I passed on the way to the library with my daughter here in Guelph.

Merry Christmas everyone!