GraphQL with nested schema returning null - node.js

Question

I am trying to return a mongodb document upon a graphql query but getting null value. No error is being shown. The mongodb query works fine with mongoshell or mongoose.
Here is the schema, typedef and resolver:
const unionSchema = new Schema(
{
geometry: mongoose.Schema.Types.MultiPolygon,
properties: {
Divi_name: String,
Dist_name: String,
Upaz_name: String,
Uni_namae: String,
},
},
{ collection: "unionbounds" }
);
const union = mongoose.model("Union", unionSchema);
const typeDefs = `
type Query {
data: Union
}
type Union {
properties: Props
}
type Props{
Dist_name: String,
}
`;
const resolvers = {
Query: {
data: () => {
union.findOne(
{
geometry: {
$geoIntersects: {
$geometry: {
type: "Point",
coordinates: [90, 22],
},
},
},
},
"properties"
);
},
},
};
Mongoshell query returns the document:
{
properties: {
Div_ID: '10',
Dist_ID: '04',
Upz_ID: '28',
Un_ID: '95',
Un_UID: '10042895',
Divi_name: 'Barisal',
Dist_name: 'Barguna',
Upaz_name: 'Barguna Sadar Upazila',
Uni_name: 'Naltona',
Area_SqKm: 45.7658667915
},
_id: 6001e54a51c6d49215322f94
}
My suspicion is that I am doing something wrong in the resolver function. I would appreciate any suggestion.

Answer 1

The problem was indeed the resolver function. Following code worked after returning the result from the callback function and using async .. await.
const resolvers = {
Query: {
data: async () => {
var value;
await union.findOne(
{
geometry: {
$geoIntersects: {
$geometry: {
type: "Point",
coordinates: [90, 22],
},
},
},
},
"properties",
function (err, result) {
value = result;
}
);
return value;
},
},
};