prettier-plugin-pg

This is a work-in-progress plugin for prettier to support formatting of PostgreSQL-flavour SQL, including formatting view and function bodies as SQL, PL/pgSQL, Python (plpython), JavaScript (plv8) etc.

Guiding principles

Try and match pg_dump-style capitalisation and word order, but with prettier line-wrapping/indentation.

• Capitalise keywords
• Use lower case for case-insensitive identifiers (table/column/function/etc names)
• Only escape case-insensitive identifiers if they are reserved words
• Always escape identifiers if they are reserved words
• Always escape case-sensitive identifiers (obviously)
• Where a statement can be expressed in many orders, express it in the same order that pg_dump would
• Try not to add/remove things (e.g. functions are volatile by default, mark them as VOLATILE in the output if and only if they were marked as such in the input (otherwise omit))
• Be safe! If we don't understand something, throw an error - don't just carry on regardless!

How to use it

Don't! We're not ready yet!

git clone git@github.com:benjie/prettier-plugin-pg.git
cd prettier-plugin-pg
yarn

Then compile the source (watch flag is optional):

yarn tsc --watch

And in another terminal:

yarn test

How it works / history

We use pg-query-native which uses libpq_query to parse the SQL using the same parser code that PostgreSQL uses internally.

We then took the deparser from pg-query-parser as the foundation for the printer, and converted it from using strings internally to using prettier's formatting commands. [This is where we're working currently.]

We've not got this far yet, but next we'll be adding a library of tests (if you have any particularly tricky SQL, please submit it!) to ensure that nothing is corrupted.

Finally we'll be optimising the formatting of the output queries - putting the groups and lines in the correct places.

Status

Very much a work in progress - do NOT use this for basically ANYTHING yet, we've got a long way to go.

Contributing

Help would be very much appreciated - just jot down in an issue what you'd like to do and if you get the nod (which tends to be fairly prompt!) then please send a PR. Issues will be opened up to other contributors after a short period of inactivity, so you're encouraged to open a PR before it's ready to merge, just mark it as [WIP] in the PR title.

Self-promotion

While I've got your attention:

• my open source work is self-funded through freelance consulting work and generous donations from the community, you can support my open source work via Patreon, or PayPal
• you can follow me on Twitter: @benjie
• if you're looking for an instant GraphQL server for your PostgreSQL database that leverages the power of PostgreSQL and doesn't fall foul of N+1 issues, check out PostGraphile (formerly PostGraphQL)