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Installation

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

This module has a peer dependency on @prisma/client. You can check the supported versions in the package.json (peerDependencies).

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)

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({ where: baseArgs.where }),
  { 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: (record) => ({ id: record.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.

Custom Edges & Nodes

By default, the edge consists of the cursor and the node. If you would like to add additional fields to the edge or the node, you can pass the following option:

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

const result = await findManyCursorConnection(
  (args) => client.todo.findMany(args),
  () => client.todo.count(),
  { first: 5, after: 'eyJpZCI6MTZ9' },
  {
    recordToEdge: (record) => ({
      node: { ...record, extraNodeField: 'Foo' },
      extraEdgeField: 'Bar',
    }),
  }
)

Out-of-the box this will have the revised types inferred for you.

Resolve information

You can pass GraphQL resolve information into the options to automatically remove extra Prisma queries for fields that are not present in your GraphQL query. This is mainly useful if you are not using totalCount for your pagination logic or you only want to query totalCount without any edges.

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

const resolveInfo: GraphQLResolveInfo = {
  // ...
}

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

Contributing

# Setup the test database
yarn prisma migrate dev --preview-feature

# 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