Autocompletion in GraphQL resolvers with JavaScript
Problem
When using GraphQL with TypeScript, you always get autocompletion for the Prisma Client instance in your GraphQL resolvers because then the context
object can be typed – no matter if folks are using Nexus, TypeGraphQL or SDL first. This immensely helps with autocompletion and preventing unwanted errors.
Unfortunately, this needs a little more effort when you're working in plain JavaScript. Suppose we have a resolver like this:
filterPosts: (parent, args, ctx) => {
return ctx.prisma.post.findMany({
where: {
OR: [
{ title: { contains: args.searchString } },
{ content: { contains: args.searchString } },
],
},
})
}
Now whenever you type ctx.
VS Code will provide unnecessary options in the autocomplete which is undesirable.
VS Code doesn't know the type of the context
object so it can't provide any intellisense for it, which is why unwanted suggestions are displayed.
Solution
To overcome this, you need to add a JSDoc comment named typedef
to "import" the correct type of your PrismaClient
instance.
// Add this to the top of the file
/**
* @typedef { import("@prisma/client").PrismaClient } Prisma
*/
Note: You can learn more about JSDoc here.
Finally, you need to type your resolver arguments. For simplicity, ignore the parent
and args
parameters. So the resolver should now look like this:
/**
* @param {any} parent
* @param {{ searchString: string }} args
* @param {{ prisma: Prisma }} ctx
*/
filterPosts: (parent, args, ctx) => {
return ctx.prisma.post.findMany({
where: {
OR: [
{ title: { contains: args.searchString } },
{ content: { contains: args.searchString } },
],
},
})
}
This will tell VS Code that the context
has a property named prisma
and the type is Prisma
which was defined in the @typedef
above.
And voilà, autocompletion in plain JavaScript.
The final file should look something like:
/**
* @typedef { import("@prisma/client").PrismaClient } Prisma
* @typedef { import("@prisma/client").UserCreateArgs } UserCreateArgs
*/
const { makeExecutableSchema } = require('graphql-tools')
const typeDefs = `
type User {
email: String!
id: ID!
name: String
posts: [Post!]!
}
type Post {
author: User
content: String
id: ID!
published: Boolean!
title: String!
}
type Query {
feed: [Post!]!
filterPosts(searchString: String): [Post!]!
post(where: PostWhereUniqueInput!): Post
}
type Mutation {
createDraft(authorEmail: String, content: String, title: String!): Post!
deleteOnePost(where: PostWhereUniqueInput!): Post
publish(id: ID): Post
signupUser(data: UserCreateInput!): User!
}
input PostWhereUniqueInput {
id: ID
}
input UserCreateInput {
email: String!
id: ID
name: String
posts: PostCreateManyWithoutPostsInput
}
input PostCreateManyWithoutPostsInput {
connect: [PostWhereUniqueInput!]
create: [PostCreateWithoutAuthorInput!]
}
input PostCreateWithoutAuthorInput {
content: String
id: ID
published: Boolean
title: String!
}
`
const resolvers = {
Query: {
/**
* @param {any} parent
* @param {any} args
* @param {{ prisma: Prisma }} ctx
*/
feed: (parent, args, ctx) => {
return ctx.prisma.post.findMany({
where: { published: true },
})
},
/**
* @param {any} parent
* @param {{ searchString: string }} args
* @param {{ prisma: Prisma }} ctx
*/
filterPosts: (parent, args, ctx) => {
return ctx.prisma.post.findMany({
where: {
OR: [
{ title: { contains: args.searchString } },
{ content: { contains: args.searchString } },
],
},
})
},
/**
* @param {any} parent
* @param {{ where: { id: string }}} args
* @param {{ prisma: Prisma }} ctx
*/
post: (parent, args, ctx) => {
return ctx.prisma.post.findUnique({
where: { id: Number(args.where.id) },
})
},
},
Mutation: {
/**
* @param {any} parent
* @param {{ title: string, content: string, authorEmail: (string|undefined) }} args
* @param {{ prisma: Prisma }} ctx
*/
createDraft: (parent, args, ctx) => {
return ctx.prisma.post.create({
data: {
title: args.title,
content: args.content,
published: false,
author: args.authorEmail && {
connect: { email: args.authorEmail },
},
},
})
},
/**
* @param {any} parent
* @param {{ where: { id: string }}} args
* @param {{ prisma: Prisma }} ctx
*/
deleteOnePost: (parent, args, ctx) => {
return ctx.prisma.post.delete({
where: { id: Number(args.where.id) },
})
},
/**
* @param {any} parent
* @param {{ id: string }} args
* @param {{ prisma: Prisma }} ctx
*/
publish: (parent, args, ctx) => {
return ctx.prisma.post.update({
where: { id: Number(args.id) },
data: { published: true },
})
},
/**
* @param {any} parent
* @param {UserCreateArgs} args
* @param {{ prisma: Prisma }} ctx
*/
signupUser: (parent, args, ctx) => {
return ctx.prisma.user.create(args)
},
},
User: {
/**
* @param {{ id: number }} parent
* @param {any} args
* @param {{ prisma: Prisma }} ctx
*/
posts: (parent, args, ctx) => {
return ctx.prisma.user
.findUnique({
where: { id: parent.id },
})
.posts()
},
},
Post: {
/**
* @param {{ id: number }} parent
* @param {any} args
* @param {{ prisma: Prisma }} ctx
*/
author: (parent, args, ctx) => {
return ctx.prisma.post
.findUnique({
where: { id: parent.id },
})
.author()
},
},
}
const schema = makeExecutableSchema({
resolvers,
typeDefs,
})
module.exports = {
schema,
}