pglite VS otj-pg-embedded

Hey HN! For a few months, I've been building pgmock at work for our E2E and unit test suite. It emulates Postgres in WebAssembly and has full feature parity with production databases.

The cool thing about it is that you don't need any external processes or proxies. If your platform can run WASM (Node.js, browser, etc.), it can probably run pgmock. Creating a new database with mock data is as simple as creating a JavaScript object.

It's a bit different from the amazing pglite [1] (which inspired me to open-source pgmock in the first place). While pgmock runs an x86 emulator, pglite compiles a Postgres fork to native WASM directly and is hence much faster and more lightweight. However, it only supports single-user mode and a select few extensions, so you can't connect to it with normal Postgres clients (which is quite crucial for E2E testing).

Theoretically, it could be modified to run any Docker image on WebAssembly platforms. Anything specific you'd like to see?

Happy hacking!

[1] https://github.com/electric-sql/pglite

I've found postgres via docker to be fine for dev and testing, but there are various epheremal postgres scripts, plus this could be promising for node stuff https://github.com/electric-sql/pglite if it works out. I'd imagine if this does work out we'll see the same kind of builds for other runtimes as well (like python)

> Use SQLite for everything, or Postgres if you outgrow it.

Or both! ElectricSQL syncs front end SQLlite back to server side postgres. And they just rebuilt postgres on pure WASM (https://github.com/electric-sql/pglite). All ties together with a CRDT.

I'm not affiliated, but just think it's just cool to imagine calls to front end sqllite as the be-all-end-all.

Anyone have an opinion of embedded-postgres vs https://github.com/opentable/otj-pg-embedded (of which its a fork) for Clojure use?

Can you elaborate a bit on this part? I'm still unsure why it's unadvised to do this, as I understood from other commenters it's because there is no official support for it correct? Why can't I use opentable for instance? https://github.com/opentable/otj-pg-embedded

It's pretty easy to run embedded postgres on the JVM: https://github.com/opentable/otj-pg-embedded

The defaults create a temporary DB which is useful for dev & tests, but a pair of calls to .setCleanDataDirectory(false) and .setDataDirectory("...") will change that.

If you don't like the default postgres version, you may select one from https://search.maven.org/search?q=io.zonky.test.postgres or include your own postgres binary.

I've been using this embedded PostgreSQL thing for tests:

https://github.com/opentable/otj-pg-embedded

It's very simple to use and works perfectly. The one problem, and it's a significant one, is that it only ships one version of PostgreSQL, and adding another was difficult enough that I didn't.