kevinmichaelchen

tsyringe isn't type-safe

• Token 'Greeter' is supposed to match Greeter (needs greet).
• We register WrongGreeter (only has sayHello).
• TypeScript passes (npx tsc --noEmit) because the string token is untyped.
• Runtime blows up: this.greeter.greet is not a function.

Run:

npm install

kevinmichaelchen

What's New in Effect v4

Table of Contents

• Schema Type System
• Separate Decode/Encode Services
• Explicit JSON Serialization
• First-Class Transformations
• First-Class Filters
• Constructor API

kevinmichaelchen

Testing Animated SVG in GitHub Markdown

This is a test to see if animated D2 SVG files work in GitHub's Markdown renderer.

Method 1: Object Tag

Your browser doesn't support embedded SVG. View the diagram directly.

kevinmichaelchen

GraphQL Codegen + Temporal Zod Demo

A demonstration of using GraphQL Codegen to generate [Zod][zod] schemas with Temporal type support using Deno and TypeScript.

kevinmichaelchen

Temporal Zod Deno Demo

A demonstration of using temporal-polyfill and temporal-zod in a Deno TypeScript project, focusing on Temporal.Instant validation and coercion.

What This Demonstrates

This project shows how temporal-zod schemas can accept either:

• A Temporal.Instant instance

kevinmichaelchen

Functional Domain-Driven Design with Effect-TS Monoid Value Objects

Sources

• Domain-driven design in functional programming
• DomainModelingwithMonoids.pdf
• Railway-oriented Programming
• Referential transparency
• Functional Core Imperative Shell

kevinmichaelchen

CUPID: Properties for Joyful Code

CUPID is a framework for creating "joyful code" that humans can understand and enjoy working with. As Martin Fowler noted: "Good programmers write code that humans can understand."

The Five Properties

🧩 Composable

kevinmichaelchen

🔄 Prisma vs Kysely: Unordered Migrations Comparison

📋 Executive Summary

Prisma does not suffer from the same unordered migrations problem that affects Kysely. While Kysely strictly enforces alphabetical/chronological ordering of migrations and fails when migrations are executed out of order, Prisma uses a more flexible approach that tracks migration history in the database and provides tools to handle divergent migration histories.

⚠️ The Kysely Problem

kevinmichaelchen

Kysely Migration Ordering: Handling Parallel Development

The Problem

When multiple developers work on feature branches simultaneously, they often create migrations with timestamps that become out of order when merged. This is a common scenario:

• Developer A creates migration 20240112_1200_add_users.sql on their feature branch
• Developer B creates migration 20240112_1201_add_products.sql on their feature branch
• Developer B merges first, production runs the 12:01pm migration
• Developer A merges second, but now there's a problem...

kevinmichaelchen

Migration Systems: Traditional Timestamp-Based vs Atlas

If you've ever seen Kysely return the error below, this post is for you.

☠️ Error: corrupted migrations: previously executed migration

The Problem with Traditional Timestamp-Based Migration Systems