graphql-typed-client/src/client/applyTypeMapperToVariable.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 { LinkedType } from './linkTypeMap'
import { TypeMapper } from './applyTypeMapperToResponse'
import { getFieldFromPath } from './getFieldFromPath'

const applyRecursively = (root: LinkedType, data: any, typeMapper: TypeMapper, path: string[]): any => {
  if (data === null || data === undefined) return data
  else {
    const field = path.length > 0 ? getFieldFromPath(root, path) : undefined
    const specificMapper = field ? typeMapper[field.type.name] : undefined
    if (specificMapper !== undefined) return specificMapper.serialize(data)
    else if (Array.isArray(data)) return data.map(i => applyRecursively(root, i, typeMapper, path))
    else if (typeof data === 'object')
      return Object.keys(data).reduce<any>((r, k) => {
        r[k] = applyRecursively(root, data[k], typeMapper, [...path, k])
        return r
      }, {})
    else return data
  }
}

export const applyTypeMapperToVariable = (value: any, root: LinkedType, typeMapper?: TypeMapper) => {
  if (!typeMapper) return value
  const specificMapper = typeMapper[root.name]
  if (specificMapper !== undefined) return specificMapper.serialize(value)
  return applyRecursively(root, value, typeMapper, [])
}