Proof of concept for extracting a the query created by a generated document node.

extractQueryProperty.ts

type Query<TData> = {
	data: TData;
};

type QueryOne = {
	queryOne: {
		foo: string;
	};
};

type QueryTwo = {
	queryTwo: {
		foos: string[];
	};
};

const queryOne: QueryOne = { queryOne: { foo: 'bar' } };
const queryTwo: QueryTwo = { queryTwo: { foos: ['a', 'b', 'c'] } };

const dictionary = { queryOne, queryTwo };
const map = new Map(Object.entries(dictionary));

type QueryResult<TData = any> = {
	data?: TData | undefined;
};

type TypedDocument<Result = { [key: string]: any }> = {
	key: string;
	__resultType?: Result;
};

const useQuery = <TData>(query: TypedDocument<TData>): QueryResult<TData> => ({
	data: (map.get(query.key) as unknown) as TData | undefined
});

const extractQueryProperty = <TData, TKey extends keyof TData>(
	query: TypedDocument<TData>,
	key: TKey
): TData[TKey] | null => {
	const { data } = useQuery(query);

	if(!data) {
		return null;
	}

	return data[key];
};