Apollo-server: Regarding circular dependencies

[m64253]

This how I understood how to handle circular dependencies, wrap in function & return array. Reference: http://dev.apollodata.com/tools/graphql-tools/generate-schema.html

So if I do this:

// file: Author.js
const Book = require('./Book');

const Author = `
  type Author {
    name: String
    books: [Book]
  }
`;

module.exports = () => [Author, Book];

// -----------------------------------

// file: Book.js
const Author = require('./Author');

const Book = `
  type Book {
    title: String
    author: Author
  }
`;

module.exports = () => [Book, Author];

// -----------------------------------

// file: schema.js
const Author = require('./Author');

const RootQuery = `
  type RootQuery {
    author(name: String): Author
  }
`;
const SchemaDefinition = `
  schema {
    query: RootQuery
  }
`;

const schema = makeExecutableSchema({
  typeDefs: [SchemaDefinition, RootQuery, Author],
  resolvers: {}
});

It will result in the following error:

Error: typeDef array must contain only strings and functions, got object

I'm sure I misunderstood something and any help pointing me in the right direction is highly appreciated.

[linonetwo]

There is no need to import Book to where Author is, just combine them at schema.js. Since the order of graphQL file is unaffected with it.

[helfer]

I think the error you're getting because require('./Author') actually gives you an object, which contains more stuff than what you exported. Other than that, it all looks correct.

[m64253]

Thanks for the replies it turns out that all it need was some rubber ducking to realise the issue. All I needed to do is handle circular dependencies node style, export before require.

Like this:

// file: Author.js
module.exports = () => [Author, Book];

const Book = require('./Book');

const Author = `
  type Author {
    name: String
    books: [Book]
  }
`;
// -----------------------------------

// file: Book.js
module.exports = () => [Book, Author];

const Author = require('./Author');

const Book = `
  type Book {
    title: String
    author: Author
  }
`;
// -----------------------------------

// file: schema.js
const Author = require('./Author');

const RootQuery = `
  type RootQuery {
    author(name: String): Author
  }
`;
const SchemaDefinition = `
  schema {
    query: RootQuery
  }
`;

const schema = makeExecutableSchema({
  typeDefs: [SchemaDefinition, RootQuery, Author],
  resolvers: {}
});

[eddyerburgh]

If anyone wants to see this in a working project - https://github.com/eddyerburgh/express-graphql-boilerplate