Installation

yarn add @devoxa/prisma-relay-cursor-connection

This module has a peer dependency on @prisma/client@^2.0.0.

Usage

General Usage

This module validates the connection arguments to make sure they work with Prisma. The following combinations are supported:

• {} All resources
• { first: number } The first X resources
• { first: number, after: string } The first X resources after the id Y
• { last: number } The last X resources
• { last: number, before: string } The last X resources before the id Y

Two cases need to be checked in your code if you are passing in user-provided data to prevent the user from reading out too many resources at once:

• One of first | last has to be defined
• first | last have to be below a reasonable maximum (e.g. 100)

If you are encoding your cursors outside of this module, you will also need to decode them before passing them.

import {
  findManyCursorConnection,
  ConnectionArguments,
} from '@devoxa/prisma-relay-cursor-connection'

const result = await findManyCursorConnection(
  (args) => client.todo.findMany(args),
  () => client.todo.count(),
  { first: 5, after: '5c11e0fa-fd6b-44ee-9016-0809ee2f2b9a' } // typeof ConnectionArguments
)

Type-Safe Arguments

You can also use additional FindManyArgs while keeping type safety intact:

import { findManyCursorConnection } from '@devoxa/prisma-relay-cursor-connection'

const baseArgs = {
  select: { id: true, isCompleted: true },
  where: { isCompleted: true },
}

const result = await findManyCursorConnection(
  (args) => client.todo.findMany({ ...args, ...baseArgs }),
  () => client.todo.count(baseArgs),
  { last: 5, before: '5c11e0fa-fd6b-44ee-9016-0809ee2f2b9a' }
)

// Type error: Property text does not exist
result.edges[0].node.text

Custom Cursors

By default, the cursor is the id field of your model. If you would like to use a different field, a compound index, or handle encoding/decoding, you can pass the following options:

import { findManyCursorConnection } from '@devoxa/prisma-relay-cursor-connection'

const result = await findManyCursorConnection(
  (args) => client.todo.findMany(args),
  () => client.todo.count(),
  { first: 5, after: 'eyJpZCI6MTZ9' },
  {
    getCursor: (node) => ({ id: node.id }),
    encodeCursor: (cursor) => Buffer.from(JSON.stringify(cursor)).toString('base64'),
    decodeCursor: (cursor) => JSON.parse(Buffer.from(cursor, 'base64').toString('ascii')),
  }
)

You can find more examples for custom cursors in the unit tests.

Contributing

# Setup the test database
yarn prisma migrate up --experimental --create-db
yarn prisma generate

# Run the tests
yarn test

Contributors

Thanks goes to these wonderful people (emoji key):

This project follows the all-contributors specification. Contributions of any kind welcome!

License

MIT