resolveMiddleware.jsx

/*
export default new GraphQLObjectType({
  name: 'User',
  description: 'A user',
  fields: () => ({
    first_name: {
      type: GraphQLString,
      description: 'The first name of the user.'
    },
    email: {
      type: GraphQLString,
      description: 'The email of the user',
      resolve: when(or(isAdmin, isSelf))
    }
  })
});
*/

import P from 'bluebird';

export function when(...conditions) {
  return (rootValue, params, info) => {

    var results = conditions.map(f => {

      let authed = f(rootValue, params, info);

      return authed === false ? P.reject() : authed;

    });

    return P.all(results)

    .then(() => rootValue[info.fieldName])

    .catch(() => null);

  };
}

export function or(...conditions) {
  return (rootValue, params, info) => {

    var results = conditions.map(f => {

      let authed = f(rootValue, params, info);

      return authed === false ? P.reject() : authed;

    });

    return P.any(results);

  };
}

export function isAdmin(rootValue, params, info) {
  const authedUser = info.rootValue.authedUser;
  if (!authedUser) return false;
  return authedUser.isAdmin;
};


export function isSelf(rootValue, params, info) {
  const authedUser = info.rootValue.authedUser;
  if (!authedUser) return false;
  return authedUser._id.toString() === rootValue._id.toString();
};