I'm trying to put together a simple endpoint following the Fastify with Typescript docs here:
https://www.fastify.io/docs/v3.1.x/TypeScript/
export default async function foo(fastify: any) {
const MyInstance = new Foo(fastify.db);
app.get<{ Querystring: IQueryString, Headers: IHeaders }>(
"/foo",
async (request: FastifyRequest, reply: FastifyReply) => {
console.log(request.query); // *prints query object*
const { queryObj } = request.query; // *Gives error: Object is of type 'unknown'*
const result = await MyInstance.getFoo(queryObj);
reply.status(200).send(result);
}
);
}
Why do I get the error when I try to access the request.query object and how do I fix it?
By default FastifyRequest.query's type RequestQuerystringDefault maps to unknown because one cannot guess which attributes/type you'll want to set for it.
Should you have a defined type for the query of some request, just define that request type and use it:
type MyRequest = FastifyRequest<{
Querystring: { queryObj: MyQueryObject }
}>
then specify it as the expected request type:
async (request: MyRequest, reply: FastifyReply) => {
const { queryObj } = request.query // Ok
}