Joonas' blog

Security Testing Supabase PostgREST

Sun, 06 Apr 2025 00:00:00 GMT

Some common enumeration, recon and exfiltration methods for Supabase

Keep your API elegant only in its signature

Tue, 25 Feb 2025 00:00:00 GMT

Messy code inside a function is fine if the call site stays simple. A worked example from an internal API client, inspired by React's design principles.

Bringing

Mon, 19 Aug 2024 00:00:00 GMT

How React Server Components change a design system

Next.js + Supabase app in production: what would I do differently

Fri, 16 Aug 2024 00:00:00 GMT

My learnings for building a Next.js and Supabase app and keeping it running in production

How does Apple wifi password sharing work?

Thu, 01 Aug 2024 00:00:00 GMT

A look into how Apple devices share WiFi passwords between (semi-anonymous) devices without internet

Visiting Japan

Fri, 19 Jul 2024 00:00:00 GMT

Notes from a trip to Japan: eSIMs, cash and 7/11 ATMs, Suica, hotels, food, and what to see in Tokyo, Osaka, Kyoto and Hiroshima.

Next.js: request parameter reference

Wed, 01 Nov 2023 00:00:00 GMT

How to read route params, query params, headers, cookies and the client IP, and how to redirect, in each kind of Next.js component and handler.

Migrating to PKCE-compatible generateLink in Supabase

Sat, 02 Sep 2023 00:00:00 GMT

auth-helpers-nextjs 0.7.0 made PKCE the default and broke generateLink. What changed, and the route handler that fixes it.

Next.js app directory: URL-synced state

Thu, 10 Aug 2023 00:00:00 GMT

How to store state in URL with Next.js app directory

PostgREST/Supabase: joins and join conditions

Tue, 08 Aug 2023 00:00:00 GMT

A look at how postgREST does joins and the gotchas involved

How to fix a NPM package mess

Fri, 28 Jul 2023 00:00:00 GMT

How to fix broken npm installs, starting with a clean reinstall and a known-good package-lock.json, then missing packages and binaries.

Git: set working directory contents to a commit

Fri, 28 Jul 2023 00:00:00 GMT

Update files in the working tree to match the version in given [commitref] without updating HEAD

Blog idea hack: source your ideas from web history

Thu, 27 Jul 2023 00:00:00 GMT

A method to write about topics your past self wishes existed

PostgREST datetime operators

Mon, 24 Jul 2023 00:00:00 GMT

Quick reference to PostgREST operator behavior with datetime columns

Opinionated UI: SVG icons in React

Fri, 21 Jul 2023 00:00:00 GMT

Opinionated way to use SVGR to serve SVG icons in a React design system library

Implement user impersonation in Supabase

Wed, 21 Jun 2023 00:00:00 GMT

Let admins log in as any user in a Next.js and Supabase app, with the code to start and stop impersonation.

Generating Supabase JWT/access token manually

Wed, 21 Jun 2023 00:00:00 GMT

How to manually generate JWT tokens to use Supabase services as any user

Type-safe prop passing in Next.js server components

Tue, 20 Jun 2023 00:00:00 GMT

Flexible method for easily passing typed data from server in Next.js server components

Creating a Postgres function for a Supabase RLS policy

Tue, 20 Jun 2023 00:00:00 GMT

Postgres function templates that move repeated access checks out of your Supabase RLS policies, starting with a join table membership check.

Opinionated UI:

Mon, 05 Jun 2023 00:00:00 GMT

Opinionated way to create a Button component in a React design system library

Building complex and interactive forms for React

Sun, 02 Oct 2022 00:00:00 GMT

How I built a complex form for React (with react-hook-forms). An introduction and learned best practices on how some common complex form usecases might be handled.

2D Navmesh generation and pathfinding in Javascript

Sun, 03 May 2020 00:00:00 GMT

Minimal-dependency navmesh generation and path-finding in Javascript

JSON Serialization might be your Rails bottleneck

Sun, 29 Mar 2020 00:00:00 GMT

Why your Rails app might surprisingly be bottlenecked by JSON serialization and what can you do about it

PostGIS marker culling