Adding a scalar from a library

[mmahalwy]

When using a library such as graphql-scalars for the JSON scalar, it's unclear how to add it to Giraphql. I tried this

const JsonType = builder.scalarType('GraphQLJSON', GraphQLJSON);

which resulted to error below:

Seems like the type needs to change to:

description?: string | null;
extensions?: Readonly<Record<string, unknown>> | null;

Narrowed it down to this:
https://github.com/hayes/giraphql/blob/1da1283475089311aed09a1c5079007e9abb7abf/packages/core/src/types/global/type-options.ts#L28

[hayes]

There are 2 methods:

scalarType let's you define your own scalars by implementing methods directly.

addScalarType let's you add existing scalar definitions.
https://giraphql.com/guide/scalars#adding-graphql-scalars

[mmahalwy]

Awesome, thank you @hayes!

[baconcheese113]

Trying this with DateTime from graphql-iso-date and it's TS definitions from DefinitelyTyped with this line:

import { GraphQLDateTime } from 'graphql-iso-date'

export const builder = new SchemaBuilder<{
    Context: IContext;
    PrismaTypes: PrismaTypes
    Scalars: {
        DateTime: {
            Input: Date
            Output: Date
        }
    }
}>({
    plugins: [PrismaPlugin],
    prisma: {
        client: prisma,
    },
})
builder.addScalarType("DateTime", GraphQLDateTime, {})

and I get the following error

Argument of type 'GraphQLScalarType' is not assignable to parameter of type 'GraphQLScalarType<unknown, unknown>'.
Type 'GraphQLScalarType' is missing the following properties from type 'GraphQLScalarType<unknown, unknown>': specifiedByURL, [Symbol.toStringTag]

This must be a common scalar type to add, any ideas what I'm doing wrong?

[hayes]

I think the type definitions from graphql-iso-date might just be out of date, I think this is a case of having multiple versions of the graphql library installed. Personally I would use https://www.graphql-scalars.dev/docs/scalars/date-time instead.

[baconcheese113]

Ah, that worked! I just switched to

import { GraphQLDateTime } from `graphql-scalars`

So after defining that scalar is this the best way to use it with Prisma?

builder.prismaObject('Event', {
    fields: (t) => ({
        id: t.exposeID('id'),
        sensor: t.relation('sensor'),
        propagatedAt: t.field({
            type: 'DateTime',
            nullable: true,
            resolve: (event) => event.propagatedAt,
        }),
        createdAt: t.field({
            type: 'DateTime',
            resolve: (event) => event.createdAt,
        }),
    })
})

Also is there a way to import the descriptions from the prisma schema?

[hayes]

So after defining that scalar is this the best way to use it with Prisma?

Thats probably the most consistent option. Another option would be to use propagatedAt: t.expose('propagatedAt', { type: 'DateTime', nullable: true }). Either of these should work.

Also is there a way to import the descriptions from the prisma schema?

Just pushed an option for this, after upgrading you can enable this with a new prisma: { exposeDescriptions: true } option when creating the builder.

Related to the above, t.expose and t.relation, t.relatedConnection, t.prismaObject and t.prismaNode are the methods that can automatically add descriptions from the prisma schema. so using propagatedAt: t.expose('propagatedAt', { type: 'DateTime', nullable: true }) would be best if you want descriptions for your date fields