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YCM Jason
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I cook delicious TypeScript & JavaScript nuggets.

Short videos, long-form articles, and small open-source tools, mostly TypeScript, JavaScript, and the web.

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Latest video

New on YouTube

The most recent upload from the channel.

Video thumbnail: Introducing ts-migrating: Upgrade TSConfig Progressively
Introducing ts-migrating: Upgrade TSConfig Progressively

NEW 20 Jun 2025 YouTube

Your code: powerful, but not clean. Here's why 7 MODERN IIFE TRICKS IN 10 MINUTES TRY {} CATCH {} ‒ FIXED! (with a surprisingly old trick) Live Coding: Recreating Vue's Reactivity System @ Vue.js Slovenia - YCMJason Vue 3 Reactivity Reimagined - Live Coding @ Vue.js London Meetup 13 - Jason Yu
All videos YouTube
Speaking

On stage

Conference and meetup talks, mostly live-coding Vue internals from scratch.

Recreating Vue's Reactivity System Vue.js Slovenia · 2023 slides ↗
Vue 3 Reactivity Reimagined Vue.js London Meetup · 2019 slides ↗
The New Composition API Vue.js London Conf · 2019 slides ↗
Vue without View: Renderless Components Vue.js London Meetup · 2019 slides ↗
Building a Simple Virtual DOM from Scratch Manchester Web Meetup · 2018 slides ↗
Writing

Deep-dives and quick tips. The number is the read time, in minutes.

TypeScript Mutually Exclusive Unions: From `?: never` to `ExclusifyUnion` 3 min Nov 2025 ♥ 2 #typescript Introducing @ts-migrating: The Best Way To Upgrade Your TSConfig 3 min Jun 2025 ♥ 54 #typescript 7 Modern Use Cases of IIFE 7 min May 2025 ♥ 16 #javascript#typescript#webdev TRY {} CATCH {} ‒ FIXED! (with a surprisingly old trick) 3 min May 2025 ♥ 9 #javascript#typescript I Recreated Tom Riddle’s Diary, But Used My Soul Instead 👻 2 min Feb 2025 ♥ 3 #webdev#ai Advanced Typescript: Typing Partially Applicable Functions 12 min Jun 2023 ♥ 12 #typescript#functional Detecting barcode from the browser!!! 3 min Nov 2021 ♥ 47 #webdev#javascript#tutorial
All posts dev.to
Open source

Tools I shipped

Small, sharp tools I built and gave away.

ts-migrating ycmjason/

This plugin lets you upgrade to your desired compilerOptions (e.g. strict, noUncheckedIndexedAccess, erasableSyntaxOnly) across your entire codebase, while letting problematic lines fall back to the old compilerOptions.

TypeScript ★ 69 acme fishballapp/

A zero-dependency, minimalist ACME client in TypeScript that simplifies certificate generation with built-in defaults and no cryptographic complexity.

TypeScript ★ 38 inquirer-cli fishballapp/

Inquirer.js wrapper for `npx` usage.

JavaScript ★ 3 keyboard-keyboard ycmjason/

An interactive keyboard you play with your keyboard.

Vue ★ 35
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