Discussion on: Say goodbye Trycatch Hell

[Gers2017]

I usually do

async function handleRequest(req: Response, res: Request){
   const {user, error} = await getUserData(1);
   if(error){
       return res.status(400).json({error})
   }
   res.status(200).json({user})
}

interface UserData{
    name:string
    age: number
}

type UserResponse = { user: UserData | null, error: string | null }
async function getUserData(id: number): Promise<UserResponse>{
    if(id <= 0){
        return {
            user: null,
            error: "Wrong, id can't be less or equal to zero!!!" // Why this failed
        }
    }
    return {
        user: {name: "Jimmy", age: 22},
        error: null
    }
}

Or I'd just throw an error inside the getUserData function

async function handleRequest(){
    try{
        const { user } = await getUserData(1);
        const { user: user2 } = await getUserData(1);
        console.log(user, user2);
    }
    catch(e){
        console.error(e);
    }
}

interface UserData{
    name:string
    age: number
}

type UserResponse = { user: UserData | null }
async function getUserData(id: number): Promise<UserResponse>{
    if(id <= 0){
        throw Error("Wrong, id can't be less or equal to zero!!!")
    } else {
        return { user: {name: "Jimmy", age: 22} }
    }
}

[Ivan Zaldivar]

Thank you for your contribution, my friend.

Personally, I do not like to handle errors that way, I consider them incorrect, I leave you the link so you can take a look about making these exceptions: developer.mozilla.org/docs/Web/Jav...

async function getUser(id: number): Promise<User> {
  // We throw an exception.
  if (id <= 0) throw new Error("Wrong, id can't be less or equal to zero!!!");
  // Result.
  return { id, email: "[e-mail]" };
}

Now we handle it.

async function handleRequest(req: Request, res: Response) {
  const [user, err] = await promHandler(getUser(Number(req.params.id)));
  if (!user || err) return res.status(400).json({
    name: "BadRequest",
    message: err.message
  });
  res.status(200).json(user);
}

[Gers2017]

Sure, I actually like the golang pattern because is easy to read.
Also I got a different approach by asking about this.

type Result<T> = 
{ result: T, error?: undefined } ||  
{ result?: undefined, error: Error }

async function getUserData(id: number): Promise<Result<UserData>>{
    if(id <= 0){
        return {
            error: new Error("Wrong, id can't be less or equal to zero!!!");
        }
    }
    return {
        result: {name: "Jimmy", age: 22},
    }
}