I have class with method:
export default class ChatService {
static async findDMChat(companionID: number) {
return $api.post<IChat>('/findDMChat', {companion_id: companionID})
}
}
In ChatStore.setCompanion( ) I want to assign result of that method to property:
export class ChatStore {
companion = {} as IUser;
chat = {} as IChat;
constructor() {
makeAutoObservable(this)
}
async setCompanion(companion: IUser) {
this.companion = companion;
this.chat = await ChatService.findDMChat(companion.id) // Type 'AxiosResponse<IChat, any>' is missing the following properties from type 'IChat': type, idts(2739)
}
Description of the error is indicated in the code comment.
Thanks in advance.
await ChatService.findDMChat(companion.id) return the result of response, not just data. If you look at AxiosResponse type you'll see what response includes
export interface AxiosResponse<T = any, D = any> {
data: T;
status: number;
statusText: string;
headers: AxiosResponseHeaders;
config: AxiosRequestConfig<D>;
request?: any;
}
so, in your case you should get data property from response
const { data} = await ChatService.findDMChat(companion.id);
this.chat = data;
I'm using Nestjs decorators and am trying to make the most of custom decorators. I'm trying to write my own custom #Body param decorator that validates and applies multiple decorators at the same time.
Does anyone know if the below is possible? I'm having difficulty getting the second argument in the transform call of the pipes to have metadata: ArgumentMetadata.
export const MyParamDecorator = <T>(myDto: T) => {
return createParamDecorator(
(data: unknown, ctx: ExecutionContext) => {
applyDecorators( // also get SetMeta and Pipes to validate DTO
SetMetadata('thisWorks', true)
UsePipes(CustomValidationPipe, OtherPipe), // + add MyDTO - type T somehow..
);
return doAsyncWork()
},
)();
}
#Controller('users')
export class UsersController {
#Patch(':id')
update(#MyParamDecorator() asyncWork: Promise<any>) { // <------ Promise<any> is custom async opperation that will be handled. (So I can't type the DTO here..)
return reqBody;
}
}
I ran across this question because I needed a similar answer. Hopefully what I've found is helpful.
Part 1. You can do async processing in a decorator.
And, it would resolve for you, so your controller would look like:
update(#MyParamDecorator() asyncWork: any) {
Notice that Promise<any> is just any.
Part 2. You can get ArgumentMetadata using an enhancer.
Here is a quick example, let's assume METADATA__PARAM_TYPE is myType.
param-type.enhancer.ts
export const paramTypeEnhancer: ParamDecoratorEnhancer = (
target: Record<string, unknown>,
propertyKey: string,
parameterIndex: number,
): void => {
const paramTypes = Reflect.getOwnMetadata('design:paramtypes', target, propertyKey);
const metatype = paramTypes[parameterIndex];
Reflect.defineMetadata(METADATA__PARAM_TYPE, metatype, target[propertyKey]);
};
my-decorator.ts
import { paramTypeEnhancer } from './param-type.enhancer';
export const MyDecorator = createParamDecorator(
async (data: unknown, ctx: ExecutionContext): Promise<any> => {
const metatype = Reflect.getOwnMetadata(METADATA__PARAM_TYPE, ctx.getHandler());
const argument: ArgumentMetadata = {
type: 'custom',
data: undefined,
metatype: metatype,
};
// Do processing here... You can return a promise.
},
[paramTypeEnhancer],
);
See this gist for a full annotated version: https://gist.github.com/josephdpurcell/fc04cfd428a6ee9d7ffb64685e4fe3a6
I have this:
LocationController.ts
import {GenericController} from './_genericController';
interface Response {
id : number,
code: string,
name: string,
type: string,
long: number,
lat: number
}
const fields = ['code','name','type','long','lat'];
class LocationController extends GenericController{
tableName:string = 'location';
fields:Array<any> = fields;
}
const locationController = new LocationController();
const get = async (req, res) => {
await locationController._get(req, res);
}
export {get};
GenericController.ts
interface Response {
id : number
}
export class GenericController{
tableName:string = '';
fields:Array<any> = [];
_get = async (req, res) => {
try{
const id = req.body['id'];
const send = async () => {
const resp : Array<Response> = await db(this.tableName).select(this.fields).where('id', id)
if (resp[0] === undefined) {
// some error handling
}
res.status(status.success).json(resp[0]);
}
await send();
}catch (error){
// some error handling
}
}
}
What I want to do is to pass the Response interface from LocationController to the GenericController parent, so that the response is typed accurately depending on how the child class has defined it. Clearly it doesn't work like this since the interface is defined outside of the class so the parent has no idea about the Response interface in the LocationController.ts file.
I've tried passing interface as an argument in the constructor, that doesn't work. So is there a way I can make this happen? I feel like I'm missing something really simple.
Typically, generics are used in a situation like this. Here's how I'd do it:
interface Response {
id: number;
}
// Note the generic parameter <R extends Response>
export class GenericController<R extends Response> {
tableName: string = "";
fields: Array<any> = [];
_get = async (req, res) => {
try {
const id = req.body["id"];
const send = async () => {
// The array is now properly typed. You don't know the exact type,
// but you do know the constraint - R is some type of `Response`
let resp: Array<R> = await db(this.tableName).select(this.fields).where("id", id);
if (resp[0] === undefined) {
// some error handling
}
res.status(status.success).json(resp[0]);
};
await send();
} catch (error) {
// some error handling
}
};
}
import { GenericController } from "./_genericController";
interface Response {
id: number;
code: string;
name: string;
type: string;
long: number;
lat: number;
}
const fields = ["code", "name", "type", "long", "lat"];
// Here we tell the GenericController exactly what type of Response it's going to get
class LocationController extends GenericController<Response> {
tableName: string = "location";
fields: Array<any> = fields;
}
const locationController = new LocationController();
const get = async (req, res) => {
await locationController._get(req, res);
};
export { get };
If this is not enough and you wish to somehow know the exact response type you're going to get, I believe the only way is a manual check. For example:
import { LocationResponse } from './locationController';
// ... stuff
// Manual runtime type check
if (this.tableName === 'location') {
// Manual cast
resp = resp as Array<LocationResponse>
}
// ...
You could also check the form of resp[0] (if (resp[0].hasOwnProperty('code')) { ... }) and cast accordingly. There are also nicer ways to write this, but the basic idea remains the same.
Generally, a properly written class should be unaware of any classes that inherit from it. Putting child-class-specific logic into your generic controller is a code smell. Though as always, it all depends on a particular situation.
I'm just getting into Fastify with Typescript and really enjoying it.
However, I'm trying to figure out if I can type the response payload. I have the response schema for serialization working and that may be sufficient, but I have internally typed objects (such as IUser) that it would be nice to have Typescript check against.
The following works great, but I'd like to return an TUser for example and have typescript if I return something different. Using schema merely discludes fields.
interface IUser {
firstname: string,
lastname: string
} // Not in use in example
interface IUserRequest extends RequestGenericInterface {
Params: { username: string };
}
const getUserHandler = async (
req: FastifyRequest<IUserRequest, RawServerBase, IncomingMessage | Http2ServerRequest>
) => {
const { username } = req.params;
return { ... }; // Would like to return instance of IUser
};
app.get<IUserRequest>('/:username', { schema }, helloWorldHandler);
Is there an equivalent of RequestGenericInterface I can extend for the response?
Small Update: It seems that the reply.send() can be used to add the type, but it would be nice for self-documentation sake to provide T higher up.
From the documentation:
Using the two interfaces, define a new API route and pass them as generics. The shorthand route methods (i.e. .get) accept a generic object RouteGenericInterface containing five named properties: Body, Querystring, Params, Headers and Reply.
You can use the Reply type.
interface MiscIPAddressRes {
ipv4: string
}
server.get<{
Reply: MiscIPAddressRes
}>('/misc/ip-address', async (req, res) => {
res
.status(_200_OKAY)
.send({
ipv4: req.ip // this will be typechecked
})
})
After looking at the type definitions, I found out that there is also an alternative way to only type-check the handler (like in Julien TASSIN's answer), like this:
import { FastifyReply, FastifyRequest, RawReplyDefaultExpression, RawRequestDefaultExpression, RawServerDefault } from "fastify";
import { RouteGenericInterface } from "fastify/types/route";
interface IUser {
firstname: string;
lastname: string;
}
interface IUserRequest extends RouteGenericInterface {
Params: { username: string };
Reply: IUser; // put the response payload interface here
}
function getUserHandler(
request: FastifyRequest<IUserRequest>,
reply: FastifyReply<
RawServerDefault,
RawRequestDefaultExpression,
RawReplyDefaultExpression,
IUserRequest // put the request interface here
>
) {
const { username } = request.params;
// do something
// the send() parameter is now type-checked
return reply.send({
firstname: "James",
lastname: "Bond",
});
}
You can also create your own interface with generic to save writing repeating lines, like this:
import { FastifyReply, FastifyRequest, RawReplyDefaultExpression, RawRequestDefaultExpression, RawServerDefault } from "fastify";
import { RouteGenericInterface } from "fastify/types/route";
export interface FastifyReplyWithPayload<Payload extends RouteGenericInterface>
extends FastifyReply<
RawServerDefault,
RawRequestDefaultExpression,
RawReplyDefaultExpression,
Payload
> {}
then use the interface like this:
function getUserHandler(
request: FastifyRequest<IUserRequest>,
reply: FastifyReplyWithPayload<IUserRequest>
) {
const { username } = request.params;
// do something
// the send() parameter is also type-checked like above
return reply.send({
firstname: "James",
lastname: "Bond",
});
}
If you want to type the handler only, you can perform it this way
import { RawReplyDefaultExpression, RawRequestDefaultExpression, RawServerDefault, RouteHandler, RouteHandlerMethod } from "fastify";
const getUserHandler: RouteHandlerMethod<
RawServerDefault,
RawRequestDefaultExpression,
RawReplyDefaultExpression,
{ Reply: IUser; Params: { username: string } }
> = async (
req: FastifyRequest<IUserRequest, RawServerBase, IncomingMessage | Http2ServerRequest>
) => {
const { username } = req.params;
return { ... }; // Would like to return instance of IUser
};
Trying to type these was a truely awful experience. Thanks to the other answers, this is where I ended up. Bit of a code dump to make life easier for others.
request-types.ts
With this I am standardising my response to optionally have data and message.
import {
FastifyReply,
FastifyRequest,
RawReplyDefaultExpression,
RawRequestDefaultExpression,
RawServerDefault,
} from 'fastify';
type ById = {
id: string;
};
type ApiRequest<Body = void, Params = void, Reply = void> = {
Body: Body;
Params: Params;
Reply: { data?: Reply & ById; message?: string };
};
type ApiResponse<Body = void, Params = void, Reply = {}> = FastifyReply<
RawServerDefault,
RawRequestDefaultExpression,
RawReplyDefaultExpression,
ApiRequest<Body, Params, Reply>
>;
type RouteHandlerMethod<Body = void, Params = void, Reply = void> = (
request: FastifyRequest<ApiRequest<Body, Params, Reply>>,
response: ApiResponse<Body, Params, Reply>
) => void;
export type DeleteRequestHandler<ReplyPayload = ById> = RouteHandlerMethod<void, ById, ReplyPayload>;
export type GetRequestHandler<ReplyPayload> = RouteHandlerMethod<void, ById, ReplyPayload>;
export type PostRequestHandler<Payload, ReplyPayload> = RouteHandlerMethod<Payload, void, ReplyPayload>;
export type PatchRequestHandler<Payload, ReplyPayload> = RouteHandlerMethod<Payload, ById, ReplyPayload>;
export type PutRequestHandler<Payload, ReplyPayload> = RouteHandlerMethod<Payload, ById, ReplyPayload>;
Usage
get-account.ts - GetRequestHandler
export const getAccount: GetRequestHandler<AccountResponseDto> = async (request, reply) => {
const { id } = request.params;
...
const account = await Account.findOne....
...
if (account) {
return reply.status(200).send({ data: account });
}
return reply.status(404).send({ message: 'Account not found' });
};
delete-entity.ts - DeleteRequestHandler
export const deleteEntity: DeleteRequestHandler = async (request, reply) => {
const { id } = request.params;
...
// Indicate success by 200 and returning the id of the deleted entity
return reply.status(200).send({ data: { id } });
};
update-account.ts - PatchRequestHandler
export const updateAccount: PatchRequestHandler<
UpdateAccountRequestDto,
AccountResponseDto
> = async (request, reply) => {
const { id } = request.params;
...
return reply.status(200).send({ data: account });
};
register-account-routes.ts - No errors with provided handler.
export const registerAccountRoutes = (app: FastifyInstance) => {
app.get(EndPoints.ACCOUNT_BY_ID, getAccount);
app.patch(EndPoints.ACCOUNT_BY_ID, updateAccount);
app.post(EndPoints.ACCOUNTS_AUTHENTICATE, authenticate);
app.put(EndPoints.ACCOUNTS, createAccount);
};
I'm writing decorators for the following class method:
export default class API {
...
public async request(url_stub: string, options: any = {}): Promise<any> {
console.log(this)
const url = this.join_url(url_stub);
...
}
}
The functions run as expected when no decorators are applied, but when I apply one of the following decorators:
export function log_func(_target: any,
name: string,
descriptor: PropertyDescriptor): PropertyDescriptor {
const original_function = descriptor.value;
descriptor.value = (... args: any[]) => {
const parameters = args.map((a) => JSON.stringify(a)).join();
const result = original_function.apply(this, args);
const result_str = JSON.stringify(result);
console.log(`Call: ${name}(${parameters}) => ${result_str}`);
return result;
}
return descriptor;
}
export function uri_encode(parameter_index?: number) {
return (_target: any,
name: string,
descriptor: PropertyDescriptor): PropertyDescriptor => {
const original_function = descriptor.value;
descriptor.value = (... args: any[]) => {
args = args.map((arg, index) => {
if (parameter_index === undefined || index === parameter_index) {
arg = encodeURI(arg);
}
return arg;
});
const result = original_function.apply(this, args);
return result;
}
return descriptor;
}
}
as such:
#uri_encode(0)
#log_func
public async request(url_stub: string, options: any = {}): Promise<any> {
this inside the class method is now undefined. I'm guessing this is because the method is technically being called from outside the context of the class.
Is there a flaw in my design, or is this what I should expect? If so is there a way for me to retain the context while still using decorators?
The problem was in my decorator. Apparently modifying the original descriptor value with a () => {} function was the problem. Changing it to function () {} made it work.
God knows why.