interfaces.js

const R = require('ramda')

const interfaces = {...}

const unpackSelectionFromAST = R.map(s => {
  switch (s.kind) {
    case 'Field':
      if (!s.selectionSet) {
        return s.name.value
      } else {
        return `${s.name.value} { ${unpackSelectionFromAST(
          s.selectionSet.selections
        )} }`
      }
    case 'InlineFragment':
      switch (s.typeCondition.kind) {
        case 'NamedType':
          return R.compose(
            R.map(field => `${R.toLower(s.typeCondition.name.value)}_${field}`),
            R.reject(R.startsWith('__')), // apollo client compatibility (__typename)
            unpackSelectionFromAST
          )(s.selectionSet.selections)
        default:
          console.error(`${s.typeCondition.kind} unknown in selections AST`)
          break
      }
      break
    default:
      console.error(`${s.kind} unknown in selections AST`)
      break
  }
})

const makeSelection = (info) =>
  R.compose(
    fields => `{ ${R.join(',')(fields)} }`,
    R.reject(R.isNil),
    R.flatten,
    unpackSelectionFromAST,
    R.prop('selections'),
    R.prop('selectionSet'),
    R.head,
    R.prop('fieldNodes')
  )(info)

const formatPrimitiveFields = R.map(
  R.compose(
    R.fromPairs,
    R.map(([k, v]) => [R.replace(/^.*_/, '', k), v]),
    R.toPairs
  )
)

module.exports = { interfaces, makeSelection, formatPrimitiveFields }