Functions

Supabase provides Edge functions to execute code on-demand in the cloud

Prerequisites

• Deno
• Deno VSCode Extension

A rest client to trigger functions, E.g.

• Insomnia Desktop App, or
• Thunder Client VSCode Extension

Running Locally

If developing functions locally run via

yarn nx run picsa-server:supabase functions serve

Authorization

Functions may expect a user to pass auth credentials with the function. A list of available credentials can be found via

yarn nx run picsa-server:supabase status

Output will provide keys for both anonymous and service role user

anon key: eyJhbGciOiJIUzI1N....
service_role key: eyJhbGciOiJI...

Either of these can be included in the headers of your http rest client when calling functions. Usually there will be an Auth option with the request, use this to set a Bearer token with the value Output

E.g. in Insomnia:

Develop New Functions

Supabase recommends using a smaller number of functions, where each function can serve multiple purposes

As such all functions related to a specific product, e.g. the dashboard, should be grouped into a single parent function as seen in

To add a new function simply create the .ts file and add a new endpoint to call that function from the main index, e.g.

apps/picsa-server/supabase/functions/dashboard/index.ts

switch (endpoint) {
  case "my-endpoint":
    return myFunction(req);
  // ...
}

my-function.ts

export const myFunction = async (req: Request) => {
  return new Response("it works");
};

To return more structured responses you may want to use the JSONResponse and ErrorResponse utility methods included locally

Run via Rest Client

Simply make a request to the named endpoint, e.g.

http://localhost:54321/functions/v1/dashboard/my-function

Unit Testing

Whilst serving functions tests can be executed by

yarn nx run picsa-server:test-functions

In order to run tests that connect to supabase an additional .env.local file should be populated in the the functions directory with SUPABASE_ANON_KEY credentials

Tests are written using the Behavior-Driven Development module

Functions cli supports additional arguments such as --watch

yarn nx run picsa-server:test-functions --watch

Production Deployment

supabase functions deploy

Additional Links

• https://supabase.com/docs/guides/functions/local-development