Hey all - how have you all solved the multiple schema file problem with sst? I’ve looked into

graphql-tools

and also see there are a few experimental methods in the appsync sdk for creating fields, types, etc… but I was hoping to just do some sort of simple concatenation (without being too low level) and pass it into my AppSyncApi config.

graphqlApi: {
  schema:  'src/schema/schema.graphql',
}

Any ideas here? Hoping to have a structure something like

src/schema/
  -- project.schema
  -- other-entity.schema

Hey @colin, does AppSync support multiple schema files? I’m asking b/c if AppSync supports it and SST doesn’t, we should add support for it.

Heya @Frank - yeah our old serverless app did support multiple files. it looked something like this in our

serverless.yml

file

appSync:
  name:  apinamehere
  schema:
    - types/base.graphql
    - types/employer.graphql
    - types/projects.graphql
    ...

I see. Do you know if SLS is merging them into a single schema? Or AppSync takes multiple natively?

We use

@graphql-tools/merge

to generate one schema atm. Happy to share a snippet if you need

@Frank Awesome! fwiw I think SLS is just doing a big concat on those files so the graphql-tools seems good to me. Ill check this out today!

Lemme share what I did, maybe @Alex Price can spot some holes 😁

import { print } from "graphql";
import { mergeTypeDefs } from "@graphql-tools/merge";
import { loadFilesSync } from "@graphql-tools/load-files";

// Schemas is an array of file names
const mergedSchema = mergeTypeDefs(
  loadFilesSync(schemas)
);

// Write the merged schema to a file
fs.writeFileSync("merged.graphql", print(mergedSchema));

// Create the AppSync schema using the file
appsync.Schema.fromAsset("merged.graphql");

Worked well for me @Frank, thank you! What are your thoughts on adding a call to

graphql/validate

for the schema before it gets set as

mainSchema

. I had a bad path and it took me until the CloudFormation error from

sst start

to realize it. something like below. I can add some tests for this if its something you’d want to do.

const errors = validate(mergedSchema)
if (errors.length > 0) throw new Error(`Invalid schema: ${errors}`)

Ah I can see that being useful! Can you show me an example of a bad path?

yep, I accidentally left off my

src

directory when initializing the AppSyncApi.

// Single file schema (worked)
{
  schema: 'src/schema/base.graphql'
}

// Array schema (broken)
{
  schema: ['schema/base.graphql', 'schema/project.graphql']
}

I’m thinking this gave me a “blank” schema but took me a second to realize.

Ah got it. It should at least catch missing files.

Thats a good question, even though they are two slightly different problems. I think it could be useful to have both some sort of error for missing files (via a node

fs.access()

call? not sure here) as well as a graphql validation call to catch small typos and things… but its a little more overhead on the build process

Yup that makes sense. Let me put in the missing files check first.

Sweet!

Hey @colin, v0.39.0 now officially supports merging schemas 🎉

sweet!