Getting "Cannot return null" error while querying API using Graphql? [duplicate] - graphql

Question

This question already has answers here:
Why does a GraphQL query return null?
(6 answers)
Closed 3 years ago.
I am not sure what I am doing wrong. I cant query this that seems to be a very easy API using GraphQL?
https://data.brreg.no/enhetsregisteret/enhet.json
I have tried different solutions. But I get the same error/problem.
import { ApolloServer, gql, IResolverObject } from "apollo-server";
import fetch from "node-fetch";
const typeDefs = gql`
type Company {
organisasjonsnummer: Int
navn: String
}
type Query {
companies: [Company!]!
}
`;
const resolvers: IResolverObject = {
Query: {
companies: async () => {
const response = await fetch(
"https://data.brreg.no/enhetsregisteret/enhet.json"
);
const data = await response.json();
return data.results;
}
}
};
const server = new ApolloServer({
typeDefs,
resolvers
});
server.listen().then(({ url }) => {
console.log(`🚀 Server ready at ${url}`);
});
Query used in GraphQL Playground:
{
companies{
organisasjonsnummer
}
}
Error received from GraphQL Playground:
{
"errors": [
{
"message": "Cannot return null for non-nullable field Query.companies.",
"locations": [
{
"line": 2,
"column": 3
}
],
"path": [
"companies"
],
"extensions": {
"code": "INTERNAL_SERVER_ERROR",
"exception": {
"stacktrace": [
"Error: Cannot return null for non-nullable field Query.companies.",
" at completeValue (F:\\apollo-datasource-rest-example\\node_modules\\graphql\\execution\\execute.js:573:13)",
" at F:\\apollo-datasource-rest-example\\node_modules\\graphql\\execution\\execute.js:505:16",
" at process._tickCallback (internal/process/next_tick.js:68:7)"
]
}
}
}
],
"data": null
}

Answer 1

Because the JSON return from that link does not have a field called "results" , so null is resolved for the companies root query but it is expected to have a non-nullable value because its schema is defined as [Company!]!.
You should return data.data from this resolver based on the JSON structure return from that link.