graphql-typed-client/src/client/linkTypeMap.ts

A tool that generates a strongly typed client library for any GraphQL endpoint. The client allows writing GraphQL queries as plain JS objects (with type safety, awesome code completion experience, custom scalar type mapping, type guards and more)

import { TypeMap } from '../render/typeMap/renderTypeMap'

export interface LinkedArgMap {
  [arg: string]: [string, LinkedType] | undefined
}
export interface LinkedField {
  type: LinkedType
  args?: LinkedArgMap
}

export interface LinkedFieldMap {
  [field: string]: LinkedField | undefined
}

export interface LinkedType {
  name: string
  fields?: LinkedFieldMap
  scalar?: string[]
}

export interface LinkedTypeMap {
  [type: string]: LinkedType | undefined
}

export const linkTypeMap = (typeMap: TypeMap) => {
  const linkedTypeMap = <LinkedTypeMap>JSON.parse(JSON.stringify(typeMap))

  Object.keys(linkedTypeMap).forEach(t => {
    const type = <LinkedType>linkedTypeMap[t]

    if (type.fields) {
      const fields = type.fields

      Object.keys(fields).forEach(f => {
        const field = <LinkedField>fields[f]

        if (field.args) {
          const args = field.args
          Object.keys(args).forEach(key => {
            const arg = args[key]

            if (arg) {
              const [, typeName] = arg

              if (typeof typeName === 'string') {
                if (!linkedTypeMap[typeName]) {
                  linkedTypeMap[typeName] = { name: typeName }
                }

                arg[1] = <LinkedType>linkedTypeMap[typeName]
              }
            }
          })
        }

        const typeName = <LinkedType | string>field.type

        if (typeof typeName === 'string') {
          if (!linkedTypeMap[typeName]) {
            linkedTypeMap[typeName] = { name: typeName }
          }

          field.type = <LinkedType>linkedTypeMap[typeName]
        }
      })
    }
  })

  return linkedTypeMap
}