Testing SerenityOS #1: Generalize your inputs / BitmapView.h Martin Janiczek 2023-10-18 | Hey there everyone!In this first instalment of "Testing SerenityOS", we're going to show a common way to do property based testing: generalizing your inputs!Sometimes we developers get lazy and only unit-test the happy path, the simple inputs. But what if there is a buggy input just around the corner? Property based tests can easily explore the input space and find edge cases we didn't think of.We'll show this technique off on a (formerly) buggy implementation of a bitmap data structure.
TerminalTextEffects on a monochrome CRT Martin Janiczek 2025-06-07 | Trying out TerminalTextEffects on an old amber CRT from the 80s.Each effect is run twice: once with --no-colors and once with colors.TerminalTextEffects: chrisbuilds.github.io/terminaltexteffects/showroom00:00 - Intro02:05 - beams (✨)02:23 - binarypath02:48 - blackhole03:17 - bouncyballs03:53 - bubbles04:54 - burn (✨)05:16 - colorshift05:49 - crumble06:13 - decrypt07:02 - errorcorrect (✨)07:25 - expand07:32 - fireworks08:51 - highlight09:01 - laseretch (✨)10:00 - matrix10:54 - middleout11:04 - orbittingvolley11:49 - overflow11:59 - pour12:32 - print (✨✨)13:04 - rain13:18 - randomsequence13:33 - rings14:08 - scattered14:18 - slice14:28 - slide (✨)14:38 - spotlights (✨)15:00 - spray15:16 - swarm16:23 - sweep (✨)16:33 - synthgrid16:55 - unstable17:09 - vhstape17:39 - waves17:57 - wipe
Ratatui + TachyonFX on a monochrome CRT Martin Janiczek 2025-06-06 | What happens when you run the modern Rust-based TUI libraries' examples on an old amber CRT from the 80s?00:00 - Intro00:20 - RATATUI EXAMPLES00:30 - advanced-widget-impl00:43 - async-github00:53 - calendar-explorer01:14 - canvas01:38 - chart01:50 - color-explorer02:01 - colors-rgb (✨✨)02:12 - constraint-explorer02:37 - constraints02:52 - custom-widget03:10 - demo (✨)03:22 - demo203:41 - flex03:51 - gauge (✨✨)04:27 - hello-world, hyperlink04:38 - inline05:02 - input-form05:22 - minimal, modifiers05:34 - mouse-drawing05:44 - panic (💥messing up my setup)06:23 - popup, scrollbar06:44 - table06:55 - todo-list (✨)07:07 - tracing07:20 - user-input07:33 - weather (✨✨)07:43 - widget-ref-container07:53 - RATATUI-WIDGETS: barchart-grouped08:14 - barchart (✨)08:24 - block08:34 - calendar08:44 - canvas08:54 - chart, gauge (✨)09:08 - line_gauge (✨)09:22 - list (✨✨)09:35 - logo, paragraph09:50 - scrollbar, sparkline10:06 - table10:19 - tabs10:32 - TACHYONFX: basic-effects (✨✨)11:47 - effect-showcase (✨)12:28 - minimal12:38 - open-window (✨✨✨)12:52 - tweens
Parser combinators under the hood: advanced example Martin Janiczek 2025-03-24 | Let's look at how parser combinators are made, by making one from scratch.This time we'll try to parse strings like "123+55" or "99/3" and implement the helpers needed.Previous video in the series: youtu.be/hFO9G0Va__0
Parser combinators under the hood Martin Janiczek 2025-03-18 | Let's look at how parser combinators are made, by making one from scratch.
NuAshworld OST 02: The Forgotten Signal Martin Janiczek 2024-12-01 | Soundtrack for NuAshworld - a post-apocalyptic browser MMO set in the world of Fallout 2.Play NuAshworld at: nuashworld.com
NuAshworld OST 01: Dust of the Old World Martin Janiczek 2024-11-02 | Soundtrack for NuAshworld - a post-apocalyptic browser MMO set in the world of Fallout 2.Play NuAshworld at: nuashworld.com
elm-bench: easy CLI benchmarking of Elm code Martin Janiczek 2024-10-04 | elm-bench is a small CLI utility for easy benchmarking of Elm code.Get it at: martinjaniczek.gumroad.com/l/elm-bench
Removing dead feature flags from a codebase with elm-review Martin Janiczek 2024-07-02 | A showcase of removing an always-false feature flag from a real Elm codebase using elm-review.
Find PBT properties by looking at pairs Martin Janiczek 2024-05-30 | TL;DW: Think about _pairs_ of functions instead of single functions.Also, macOS presenter overlay is ... cool, and incredibly silly?
ISS Martin Janiczek 2024-03-02 | My "One Song" made while reading "How To Write One Song" by Jeff Tweedy.Chorus:ISS wants to tell you somethingBoy, are you listeningSomething scary's looming just around the bendOh, how could have we missed itQuick, honey, kiss meWish I told my kids I love them every dayVerse 1:It started happening yesterdayThe moon got pulled awayLooks like something's eating planetsIt's a crazy thing to sayAll our conflicts now are goneCountries sending soldiers homeTo waitThe sun is shining less and lessWith each and every dayElectromagnetism's screwed upAll the bees dance figure eightAll our arguments are goneNature keeps on keeping onFor nowVerse 2:The future's gloomOur certain doomIs sprinting towards usMaybe we are running towards it tooIt's hard to sayOur reference frameIs weird...The planet's darkWe're a Noah's arkSailing to some unknown placeDrifting in the outer spaceLet's take the landing slowArriving at our second homeTonight
Testing SerenityOS #2: Pairs of functions / Complex.h Martin Janiczek 2023-11-22 | Hey there everyone!In this second instalment of "Testing SerenityOS" I demonstrate a way to more easily find properties to test: considering pairs of functions.It's hard enough to try to come up with properties for a single function; counter-intuitively taking pairs of them makes the problem easier.We'll show this technique off on an implementation of complex numbers, and uncover and fix two bugs in the process.
Spears Martin Janiczek 2023-10-29 | Another quick Sunday afternoon doodle in Surge XT.This time, it all started by downloading some chiptune presets: reddit.com/r/synthrecipes/comments/fdx4vj/recipe_using_surge_for_8bit_videogame_sounds_long...and following a 1m-5m-7b-4 progression that was stuck in my head.Any similarity to a female pop artist and an outlaw song is purely coincidental :)
Testing SerenityOS - Announcement Martin Janiczek 2023-09-30 | Hey there everyone!This is just a quick announcement that I have been working on adding property based testing capabilities to SerenityOS.I'm starting a small video series where I go write different types of property based tests for the many libraries and utilities and programs that SerenityOS has, in order to teach you how to use these in your own programs.
6 7 7b 6 Martin Janiczek 2023-03-12 | Randomly picking a chord progression (hence the name) and learning Surge XT and Ableton on it resulted in a Super Meat Boy-like track!
Property based testing: tale of two shrinkers Martin Janiczek 2022-09-12 | This is a recording of an internal talk I gave at Permutive, to a mostly Scala + Elm developer audience.The aim is to explain common approaches for PBT shrinking and their issues, and raise awareness about a not so well known approach ("internal shrinking", see the Python library Hypothesis) that doesn't suffer from these issues.Shared with permission.
Property based testing: primer and examples Martin Janiczek 2022-08-15 | This is a recording of an internal talk I gave at Permutive, to a mostly Scala + Elm developer audience.The aim is to tell you what PBT is, why do it, and teach you just enough basics, principles and examples to be able to apply it in your day-to-day job.Shared with permission.
The Store pattern in Elm Martin Janiczek 2022-05-22 | Repo: github.com/Janiczek/elm-store-patternPresentation PDF: github.com/Janiczek/elm-store-pattern/raw/main/Presentation.pdf
Wordle in Elm in 1h13m17s (PB, timelapse) Martin Janiczek 2022-01-29 | I, in my infinite arrogance, thought implementing my own Wordle will be a 20min piece of cake.Well, the keyboard scoring got me. And importing Tailwind. And Set.member not taking the set as the first argument 🤦♂️Other than that, I'm pretty pleased with how well did a simple List representation hold up!Set and timelapsed to the music from Peer Gynt (Anitra's Dance and Hall of the Mountain King), specifically to the arrangement found in the game The Witness. Panic inducing!
3: Writing a property-based testing library in Elm - The core loop Martin Janiczek 2021-08-07 | Subscribe to get notified about the next video in the series!Code we'll write over the course of this tutorial: github.com/Janiczek/elm-microthesisFollow me on Twitter: http://twitter.com/janiczekI also ocassionally stream on Twitch: http://twitch.tv/martinjaniczekSupport me on Patreon: patreon.com/janiczekYour support will help me continue the series and create more videos like this one.Important timestamps:- 00:00 Intro- 00:16 Disprover.run - heart of the library- 02:03 Finished diagram- 02:30 generateAndTest- 05:02 initLoop- 05:28 generate- 06:50 Stopping conditions- 07:49 sawPassingTests and shouldTryToGenerate- 09:19 Figuring out PRNG representation- 11:05 Passing the random seed- 14:00 Checking the TODOs
2: Writing a property-based testing library in Elm - Sketching the library API Martin Janiczek 2021-05-22 | Next video to come in a week - subscribe to get notified about it.Code we'll write over the course of this tutorial: github.com/Janiczek/elm-microthesisFollow me on Twitter: http://twitter.com/janiczekI also ocassionally stream on Twitch: http://twitch.tv/martinjaniczekSupport me on Patreon: patreon.com/janiczekYour support will help me continue the series and create more videos like this one.Important timestamps:- 00:00 Intro- 00:04 Creating the Elm project- 00:46 Dreaming up an example usage- 01:20 Running the compiler with a file watcher- 01:37 Stubbing the Generator- 02:18 Stubbing Disprover.run- 02:27 Stubbing the types- 02:47 Checking the TODOs- 02:57 Outro
1: Writing a property-based testing library in Elm - Intro Martin Janiczek 2021-05-21 | Next video (with actual code!) is already in works - subscribe to get notified about it.Code we'll write over the course of this tutorial: github.com/Janiczek/elm-microthesisFollow me on Twitter: http://twitter.com/janiczekI also ocassionally stream on Twitch: http://twitch.tv/martinjaniczekSupport me on Patreon: patreon.com/janiczekYour support will help me continue the series and create more videos like this one.Link to QuickCheck paper:http://www.quviq.com/wp-content/uploads/2014/08/QuviqFlyer.pdfImportant timestamps:- 00:00 Intro- 00:13 Prerequisites- 00:31 What is property-based testing- 02:28 The two types of PBT- 03:02 How type-based shrinking works- 04:18 How integrated shrinking works- 04:54 MAIN TAKEAWAY- 05:44 Caveat of integrated shrinking: how you write generators matters- 07:41 Tradeoffs summarized- 08:36 Ending
Solving Advent of Code 2016-09 with Elm parser combinators Martin Janiczek 2020-10-26 | I've recently solved the Advent of Code problem 2016-09 and found it's quite amenable to parser combinators. So let's go through it together!Advent of Code 2016-09: adventofcode.com/2016/day/9elm/parser: package.elm-lang.org/packages/elm/parser/latest
Advent of Code 2017 - 25/25 Martin Janiczek 2017-12-25 | Reupload from twitch.tv/martinjaniczekStarts at 01:42
Advent of Code 2017 - 24/25 Martin Janiczek 2017-12-24 | Reupload from twitch.tv/martinjaniczekStarts at 01:28
Advent of Code 2017 - 23/25 Martin Janiczek 2017-12-23 | Reupload from twitch.tv/martinjaniczekStarts at 01:49
Advent of Code 2017 - 22/25 Martin Janiczek 2017-12-22 | Reupload from twitch.tv/martinjaniczekStarts at 01:17
Advent of Code 2017 - 21/25 Martin Janiczek 2017-12-21 | Reupload from twitch.tv/martinjaniczekStarts at 01:53
Advent of Code 2017 - 20/25 Martin Janiczek 2017-12-20 | Reupload from twitch.tv/martinjaniczekStarts at 02:42
Advent of Code 2017 - 19/25 Martin Janiczek 2017-12-19 | Reupload from twitch.tv/martinjaniczekStarts at 01:28
Advent of Code 2017 - 18/25 Martin Janiczek 2017-12-18 | Reupload from twitch.tv/martinjaniczekStarts at 02:11
Advent of Code 2017 - 17/25 Martin Janiczek 2017-12-17 | Reupload from twitch.tv/martinjaniczekStarts at 03:03
Advent of Code 2017 - 16/25 Martin Janiczek 2017-12-16 | Reupload from twitch.tv/martinjaniczekStarts at 00:34
Advent of Code 2017 - 15/25 Martin Janiczek 2017-12-15 | Reupload from twitch.tv/martinjaniczekStarts at 02:01
Advent of Code 2017 - 14/25 Martin Janiczek 2017-12-14 | Reupload from twitch.tv/martinjaniczekStarts at 00:49
Advent of Code 2017 - 13/25 Martin Janiczek 2017-12-13 | Reupload from twitch.tv/martinjaniczekStarts at 02:27
Advent of Code 2017 - 12/25 Martin Janiczek 2017-12-12 | Reupload from twitch.tv/martinjaniczekStarts at 01:59
Advent of Code 2017 - 11/25 Martin Janiczek 2017-12-11 | Reupload from twitch.tv/martinjaniczekStarts at 00:57
Advent of Code 2017 - 10/25 Martin Janiczek 2017-12-10 | Reupload from twitch.tv/martinjaniczekStarts at 01:17
Advent of Code 2017 - 09/25 part 2 Martin Janiczek 2017-12-09 | Reupload from twitch.tv/martinjaniczekStarts at 01:19
Advent of Code 2017 - 09/25 part 1 Martin Janiczek 2017-12-09 | Reupload from twitch.tv/martinjaniczekStarts at 01:49
Advent of Code 2017 - 08/25 Martin Janiczek 2017-12-08 | Reupload from twitch.tv/martinjaniczekStarts at 00:48
Advent of Code 2017 - 07/25 Martin Janiczek 2017-12-07 | Reupload from twitch.tv/martinjaniczekStarts at 01:36
Advent of Code 2017 - 06/25 Martin Janiczek 2017-12-06 | Reupload from twitch.tv/martinjaniczekStarts at 00:54
Advent of Code 2017 - 05/25 Martin Janiczek 2017-12-05 | Reupload from twitch.tv/martinjaniczekStarts at 01:03
