How can I combine a GraphQLObjectType with a schema created by graphql-tag with gql-tag? - apollo-server

Question

I use graphql-tag together with apollo-server-express to connect to build a graphQL endpoint for an api. At the moment I create the schema definition like this:
properties.js
let model = {}
const typeDefs = gql`
extend type Query {
property(id: Int!): [Property]
}
type Property {
title: String
street: String
postalcode: String
city: String
country: String
}
`
const resolvers = {
Query: {
property: getTheEntriesFromDB,
},
}
model.typeDefs = typeDefs;
model.resolvers = resolvers;
module.exports = model;
and server.js
const server = new ApolloServer({
modules: [
require('./modules/properties'),
],
}):
However I want to create the type 'Property' based on a database schema automatically. I found out that I can create a GraphQLObjectType like this:
const propertyType = new graphql.GraphQLObjectType({
name: 'Property',
fields: {
title: { type: graphql.GraphQLString },
street: { type: graphql.GraphQLString },
postalcode: { type: graphql.GraphQLString },
city: { type: graphql.GraphQLString },
country: { type: graphql.GraphQLString },
}
});
but I don't know how to combine this with
let model = {}
const typeDefs = gql`
extend type Query {
property(id: Int!): [Property]
}
`
const resolvers = {
Query: {
property: getTheEntriesFromDB,
},
}
model.typeDefs = typeDefs;
model.resolvers = resolvers;
module.exports = model;
to create the final schema. Can someone point me in the right direction?
Any help is highly appreciated. Thanks a lot in advance!

Answer 1

OK, after hours of trial and error and searching I found this solution which works for me:
properties.js
const { buildASTSchema, GraphQLObjectType, GraphQLSchema, GraphQLString, parse, printSchema } = require('graphql')
let model = {}
const propertyType = new GraphQLObjectType({
name: 'Property',
fields: {
title: { type: GraphQLString },
street: { type: GraphQLString },
postalcode: { type: GraphQLString },
city: { type: GraphQLString },
country: { type: GraphQLString },
}
});
let typeDefs = gql`
extend type Query {
property(id: Int!): [Property]
}
type Property {
id: Int
}
`
typeDefs.definitions[0].kind = 'ObjectTypeDefinition' //replace ObjectTypeExtension with ObjectTypeDefinition to make AST 'valid' but keep extend in gql-tag to satisfy code inspection in ide
typeDefs = parse(printSchema(buildASTSchema(typeDefs)).replace('type Query {', 'extend type Query {') + printSchema(new GraphQLSchema({ types: [ propertyType ]})).replace('type Property {', 'extend type Property {'))
const resolvers = {
Query: {
property: getTheEntriesFromDB,
},
}
model.typeDefs = typeDefs;
model.resolvers = resolvers;
module.exports = model;
The "extend" keywords are needed because Property needs to be declared inside the gql tag and Query is declared more than once throughout the project.