Update for the week ending on Friday, Mar 20, 2020

Portfolio Rebalancer

The portfolio rebalancer is a new project I started this week to rebalance portfolios so that the investor can maintain a particular ratio of assets. For example, you could say, “I want to 30% of my money in US stocks, 20% in international stocks, and 50% in bonds. Here’s my current portfolio.” And the rebalancer will tell you what assets to exchange so that you’re at the balance you want.

• Here’s a visual diary of my progress.
  • Day 1
    • Basic functionality works!
    • It can rebalance a portfolio with up to TWO holdings.
    • Spent lots of time figuring out how to wrap bootstrap-vue components so that they have the same functionality but work on arbitrary-precision numbers instead of JS-native number types (which are too imprecise for financial calculations).
  • Day 2
    • Put everything into nicer UI components like tables and cards to make everything feel more organized.
    • Started moving business logic out of the Vue components and into TypeScript controllers, where it’s easier to write unit tests for them.
  • Day 3
    • Implemented support for portfolios with up to 3 holdings.
    • Created a Firebase project to host it (https://rebalancer.mtlynch.io for now)
    • Added a CircleCI config for automatic deployment and testing
    • Spent hours trying to figure out how to use TypeScript enums as dictionary indices before finally giving up and converting the enums to const instances of a class.
  • Day 4
    • Added a bootstrap theme
    • Added a navbar
    • Wrote an About page
    • Added helper text to explain what each section is.
• It’s now sort of working for up to 3 investments.
  • I say sort of because it currently suggests trades as low as $0.01 to be perfectly balanced, but I need to put in some minimum threshold where within .1% or so should be considered fine.
• I’ve got it running in Firebase on a placeholder URL: https://rebalancer.mtlynch.io
• I added a navbar, about page, and a CircleCI configuration to automatically test and deploy every commit.
• This is my first time configuring a Vue project with TypeScript, and it’s kind of neat.
  • I’ll admit that it’s a bit annoying to have TypeScript complaining about things like “this variable might be undefined” when I’m used to an extremely passive JavaScript that does whatever I say, no matter how dumb it is.

NERD Summit

• Delivered my talk at NERD Summit (slides)
  • Also did lots of rehearsal runs.
    • Thanks to my girlfriend for being my test audience.

WanderJest

• Announced WanderJest’s official hiatus until the COVID-19 pandemic has subsided.
• Continued arranging a meeting with a comedian who runs a similar site in another city.
• Marked lots of events canceled or rescheduled.

mtlynch.io

• Upgraded to Hugo 0.67.0 (#547)
• Removed a dead link (#544)
• Realized I have a bunch of dead links but htmlproofer isn’t finding them
  • I have htmlproofer set to only report 4xx errors because it otherwise gets too many false positives, but that means I miss links that permanently get 5xx errors or where the server simply isn’t serving anymore.
  • I’m trying to switch to htmltest, which has the advantage of being Go-native (htmlproofer is Ruby), but I’m struggling to fix the false positives. (#546)
    • Submitted a small Docker improvement to htmltest (#144)

What Got Done

• Consolidated e2e tests into integration tests (#489, #490)
  • e2e tests only existed because some tests required an initial state like “add a reaction to this user’s pre-existing entry”
  • That was hard to replicate with my integration tests because the integration tests start with a fresh datastore, and I didn’t want to have to depend on a particular ordering of tests (e.g. only test reactions after we’ve tested posting so that the post is there).
  • Instead, I added a second server to my docker-compose setup that shares the datastore with the WanderJest test environment but can initialize and reset the datastore
  • Now Cypress calls this second server with the /reset HTTP request before each test.
  • I manage the “initial state” data in a simple YAML file.
  • This is a big win because now any developer can run all of my tests with a single command. The integration tests run their own local Firestore server, so it doesn’t depend on any external state.

Misc

• Lots of emailing friends to check in on how they’re doing with COVID-19.
• Diagnosed why my home VM server was running out of local disk
  • There were lots of images on the disk, but I couldn’t figure out which VMs they were associated with, because they’re just labeled with random UUIDs.
  • I’m using KVM/virsh, so the solution was:
    1. Call virsh vol-list <my-volume-pool> --details
    2. For large images, find the VM that’s using it by doing virsh domname <image UUID>
    3. If it’s an orphaned image, delete it with virsh vol-delete <image path>
• Updated the Sia Docker Image to 1.4.4
  • And then whined a lot on reddit about Sia’s annoying release process.
• Window shopped some new VM server hardware since my build is now almost 3 years old and I can build a much better one based on what I’ve learned about my usage these past few years.

Beekeeping

• Did my second post-winter quick inspection
  • Sadly, one of my two hives died.
    • They seem to have run out of honey in the last 10 days. It looks like the sugar patties I fed them on last inspection weren’t enough.
  • The other hive seems to be pretty healthy, but I’m going to supplement their food ASAP.

Dusty VCR Podcast

• Postponed all meetings and recording dates indefinitely due to COVID-19.