NOTE: This is mainly a question about the pg or Node-PostgreSQL module. It has details from Gatsby and Postgraphile, but I don't need expertise in all three, just pg.
I have a database that works great with a PostGraphile-using Express server. I can also acces it via node at the command line ...
const { Pool } = require("pg");
const pool = new Pool({ connectionString: myDbUrl });
pool.connect().then(() => console.log('connected'));
// logs 'connected' immediately
The exact same database also previously worked great with Gatsby/PostGraphile via the gatsby-source-pg plug-in ... but recently I changed dev machines, and when I try to build or run a dev server, Gatsby hangs on the "source and transform nodes" step. When I debug it, it's hanging on a call to pool.connect().
So I literally have two codebases both using PostGraphile, both with the same config, and one works and the other doesn't. Even stranger, if I edit the source code of the Gatsby plug-in in node_modules, to make it use the exact same code (which I can run at the command line successfully) ... it still hangs.
The only thing I can think of is that some other Gatsby plug-in is using up all the connections and not releasing them, but as far as I can tell (eg. by grep-ing through node_modules) no other plug-in even uses pg.
So really I have two questions:
A) Can anyone help me understand why connect would hang? Bonus points if you can help me understand why it would do so with a known-good config and only inside Gatsby (after some environmental factor changed)?
B) Can anyone help me fix it? If it might be some sort of "previous code forgot to release connections" issue, is there any way I can test for that? If I could just log new Pool().areYouBroken() somehow that would be amazingly useful.
Annoying answer: because of a bug (thank you @charmander). For further details see: https://github.com/brianc/node-postgres/issues/2300
P.S. I never did find any sort of new Pool().areYouBroken() function.