routeql.js

import gql from 'graphql-tag';
import { pick } = 'lodash'

function routeql({ query = {}, params = [], method, apiPrefix = "" }) {
  const ast = gql`
    ${query}
  `;
  if (
    ast.definitions.length > 1 ||
    ast.definitions[0].selectionSet.selections.length > 1
  ) {
    throw new Error('nested definitions are currently not supported');
  }
  const def = ast.definitions[0];
  const route = def.selectionSet.selections[0];
  const routeName = route.name.value;
  const fields = route.selectionSet.selections.map(field => field.name.value);
  const reqType = method || def.operation === "query" ? "GET" : "POST";
  const paramString = params.reduce(acc, param => `${acc}/${param}`, "/");
  const queryStrying = Object.entries(query).reduce(
    (qs, [key, value]) => `${qs}${qs.length === 1 ? "" : "&"}${key}=${value}`,
    "?"
  );
  return fetch(`${apiPrefix}/${route}/${paramString}${queryString}`, {
    method: reqType
  })
  .then(res => res.json())
  .then(data => pick(data, fields));
}

routeql({
  query: `
    query {
      document {
        id
        name
        type
      }
    }
  `,
  params: ["1"],
  apiPrefix: "/api/v1"
});