Stitch

index.js

const { makeExecutableSchema } = require('@graphql-tools/schema')
const { stitchSchemas } = require('@graphql-tools/stitch')
const { RenameObjectFields, FilterRootFields, PruneSchema, wrapSchema } = require('@graphql-tools/wrap')
const { printSchema, parse, execute, print } = require('graphql')

/// SERVICE 1

const source = /* GraphQL */ `
  type Query {
    foo(key: String!): Foo
  }

  type Foo {
    key: String
    name: String
  }
`

const inner = makeExecutableSchema({
  typeDefs: source,
  resolvers: {
    Query: {
      foo: (_, args) => ({ key: args.key, name: 'dsfjkasd' })
    }
  }
})

const config = {
  schema: inner,
  transforms: [
    new FilterRootFields(() => false),
    new PruneSchema({
      skipPruning: type => type.name === 'Foo',
    }),
    new RenameObjectFields((typeName, fieldName) => {
      if (typeName === 'Foo' && fieldName === 'key') {
        return '_my_1_key'
      }
      return fieldName
    })
  ],
  merge: {
    Foo: {
      fieldName: 'foo',
      selectionSet: '{ _mapped__s1_key }',
      args: (source) => ({ key: source._mapped__s1_key })
    }
  },
  executor: ({ document, variables }) => {
    console.log('\n\n:: executing service one\n')
    console.log(print(document))
    console.log(variables)
    return execute({ schema: inner, document, variableValues: variables })
  }
}

///  KEY SERVICE

const keySource = /* GraphQL */ `
  type Query {
    foo(id: ID!): Foo
  }

  type Foo {
    id: ID!
    _mapped__s1_key: String
  }
`

const keySchema = makeExecutableSchema({
  typeDefs: keySource,
  resolvers: {
    Query: {
      foo: (_, args) => ({
        id: args.id,
        _mapped__s1_key: 'abc',
      })
    }
  }
})

const keyConfig = {
  schema: keySchema,
  merge: {
    Foo: {
      entryPoints: []
    }
  },
  executor: ({ document, variables }) => {
    console.log('\n\n:: executing key service')
    console.log(print(document))
    console.log(variables)
    return execute({ schema: keySchema, document, variableValues: variables })
  }
}


/// STITCH

const outer = stitchSchemas({
  subschemas: [config, keyConfig]
})

console.log(printSchema(wrapSchema(config)))
// console.log(printSchema(outer))


const query = /* GraphQL */ `
  query {
    foo(id:"120") {
      id
      _mapped__s1_key
      _my_1_key
      name
    }
  }
`

const go = async () => {
  const result = await execute({
    schema: outer,
    document: parse(query),
  })

  console.log('\n\n:: result\n')
  console.log(JSON.stringify(result, null, 2))
}


go()