Struggling to make an async function wait for a database response - javascript

Thank you in advance for taking the time to help me.
I am trying to log users in using a MongoDB backend, I call an async function which makes the fetch call, and returns the login token if I get a 200 response code. :
_initialize = async userAddress => {
const token = await login(userAddress);
console.log("TOKEN:", token);
// Do other stuff with the token
}
the login function looks like this:
export const login = async address => {
const requestOptions = {
method: 'POST',
headers: { 'Content-Type': 'application/json' },
body: JSON.stringify({ address })
};
let responseCode;
fetch(`___ENDPOINT___`, requestOptions)
.then(response => {
responseCode = response.status;
return(response.json());
})
.then(data => {
if(responseCode == 200){
console.log(data.token)
const token = data.token;
return token;
}
if(responseCode == 400){
if(data.message === "User not yet registered"){
// Do nothing
return;
}
}
})
.catch(error => {
console.log(error)
});
}
The issue that I am having is that the await login() call is not being waited on, instead token is console logged as undefined.
If I remove the await keyword I receive token as :
Promise {<fulfilled>: undefined}
__proto__: Promise
[[PromiseState]]: "fulfilled"
[[PromiseResult]]: undefined
I don't get it, why is token undefined? If I log token in the .then block it is returned successfully, but this only occurs after token has been printed as undefined in the initialize function.
Its like the async function initialize is not awaiting the async login function?
Any help is greatly appreciated, thank you again for your time.

Your login function doesn't return a promise. In fact, it doesn't return anything at all. See comments:
export const login = async address => {
const requestOptions = {
method: 'POST',
headers: { 'Content-Type': 'application/json' },
body: JSON.stringify({ address })
};
// Note: Don't catch erros in this function, let them propagate
// so the caller knows what happened
// No need for `.then`/`.catch` in an `async` function, use `await`
// Wait for the initial resaponse
const response = await fetch(`___ENDPOINT___`, requestOptions);
const responseCode = response.status;
if (!response.ok) {
// Not an OK reseponse
if (responseCode == 400) {
// Parse the body to see if we have the message
const data = await response.json();
if (data.message === "User not yet registered") {
// Do nothing
return;
}
}
throw new Error("HTTP error " + responseCode);
}
// OK response, read the data from the body, this is also async
const data = await response.json();
return data.token;
};
Note that login will return the token or will return undefined if the response code was 400 and the body of that response was valid JSON that defined a message property with the text "User not yet registered". _initialize will need to check for that. Also, _initialize should handle any errors from login.

If anyone knows why the above code doesn't work, that would still be very useful to know, however I came up with a solution :
export const login = async address => {
const requestOptions = {
method: 'POST',
headers: { 'Content-Type': 'application/json' },
body: JSON.stringify({ address })
};
const response = await fetch(`___ENDPOINT___`, requestOptions)
const data = await response.json();
const responseCode = response.status;
if(responseCode == 200){
console.log(data.token)
const token = data.token;
return token;
}
if(responseCode == 400){
if(data.message === "User not yet registered"){
// Do nothing
return;
}
}
}

Related

how to await value from another await variable

I cannot figure out how should I construct my code.
Basic info:
webhook (intercom) --> google cloud functions (await values) --> post message to slack.
Issue:
My code is working fine until I need to get an value from another await function and I am not sure how should I 'pause' the second await until the first one is complete.
Code:
// first function to get the information about agent
const getTeammateInfo = async function (teammate_id) {
try {
const response = await axios.get("https://api.intercom.io/admins/" + teammate_id, {
headers: {
'Authorization': "Bearer " + INTERCOM_API_AUTH_TOKEN,
'Content-type': "application/json",
'Accept': "application/json"
}
});
const { data } = response
return data
} catch (error) {
console.error(error);
}
};
// second function, which needs values from first function in order to find data
const slackID = async function (slack_email) {
if (slackID) {
try {
const response = await axios.get("https://api.intercom.io/admins/" + slack_email, {
headers: {
'Authorization': "Bearer " + SLACK_API_TOKEN,
'Content-type': "application/json",
'Accept': "application/json"
}
});
const { user } = response
return user
} catch (error) {
console.error(error);
}
}
};
It is used within the Google Cloud Function (
exports.execute = async (req, res) => {
try {
// map of req from intercom webhook
let {
data: {
item: {
conversation_rating: {
rating,
remark,
contact: {
id: customerId
},
teammate: {
id: teammateId
}
}
}
}
} = req.body
const teammateName = await getTeammateInfo(teammateId); // this works fine
const slackTeammateId = await slackID(teammateName.email) // this is where it fails I need to get the values from 'teammateName' in order for the function slackID to work
...
} catch (error) {
console.error(error)
res.status(500)
res.json({ error: error })
}
}
I have tried with Promise.all
const [teammateName, slackTeammateId] = await Promise.all([
getTeammateInfo(teammateId),
slackID(teammateName.email)
])
But I just cannot wrap my head around this how it should work.
Thank you.
// edit:
Code is okay, I just put the wrong API into the slackID function...
Thanks for double checking.
The problem with Promise.all() is that it fires both functions at the same time and waits until both are done, so you can't chain that way.
let teammateName
let slackTeammateId
getTeammateInfo(teammateId).then(r => {
teammateName = r
slackID(teammateName.email).then(r2 => {
slackTeammateId = r2
)}
);
then() method, on the other hand, waits until your method's return and then fires out everything in the callback function.

SWR not working properly with async fetch

Recently updated SWR - now for some reason my data is not fetching properly.
const { data: expressionsData, error: expressionsError } = useSWRImmutable(
[`dashboard/expression/get-expression-analytics?startTime=${startDate}&endTime=${endDate}`, startDate, endDate],
apiRequest
);
Using this fetching,
import firebase from "./firebase";
export async function apiRequest(path, method = "GET", data) {
const accessToken = firebase.auth().currentUser
? await firebase.auth().currentUser.getIdToken()
: undefined;
//this is a workaround due to the backend responses not being built for this util.
if (path == "dashboard/get-settings") {
return fetch(`/api/${path}`, {
method,
headers: {
"Content-Type": "application/json",
Authorization: `Bearer ${accessToken}`,
},
body: data ? JSON.stringify(data) : undefined,
})
.then((response) => response.json())
.then((response) => {
if (response.error === "error") {
throw new CustomError(response.code, response.messages);
} else {
return response;
}
});
}
return fetch(`/api/${path}`, {
method,
headers: {
"Content-Type": "application/json",
Authorization: `Bearer ${accessToken}`,
},
body: data ? JSON.stringify(data) : undefined,
})
.then((response) => response.json())
.then((response) => {
console.log("error", response);
if (response.status === "error") {
// Automatically signout user if accessToken is no longer valid
if (response.code === "auth/invalid-user-token") {
firebase.auth().signOut();
}
throw new CustomError(response.code, response.message);
} else {
return response.data;
}
});
}
// Create an Error with custom message and code
export function CustomError(code, message) {
const error = new Error(message);
error.code = code;
return error;
}
// Check if a indexDb database exists
export function indexedDbdatabaseExists(dbname, callback) {
const req = window.indexedDB.open(dbname);
let existed = true;
req.onsuccess = function () {
req.result.close();
if (!existed) window.indexedDB.deleteDatabase(dbname);
callback(existed);
};
req.onupgradeneeded = function () {
existed = false;
callback(existed);
};
}
Now I'm looking at this StackOverflow thread,
useSWR doesn't work with async fetcher function
And thinking I'll just remake the fetcher to be without Async. I'm just wondering why this has stopped working though in general, and if I can just keep my existing codebase.
The error is a 400 message, it only happens with this expressions API call which takes longer to load due to the amount of data I think,
xxxx/dashboard/expression/get-expression-analytics?startTime=1648183720488&endTime=1650865720488 400 (Bad Request)
with error log
These calls are working fine, they have substantly less data though.
const { data: overall, error: psychometricError } = useSWRImmutable(
`dashboard/psychometric/get-psychometric-home?starttime=infinite`,
apiRequest
);
const { data: sentimentData, error: sentimentError } = useSWRImmutable(
[`dashboard/sentiment/get-sentiment-timefilter?startTime=${startDate}&endTime=${endDate}`, startDate, endDate],
fetchSentiment
);
Made an update to the fetch call to be more readable and specifically about the URL pathway.
import firebase from './firebase';
// Create an Error with custom message and code
export function CustomError(code, message) {
const error = new Error(message);
error.code = code;
return error;
}
export async function expressionsRequest(path, method = 'GET') {
const accessToken = firebase.auth().currentUser
? await firebase.auth().currentUser.getIdToken()
: undefined;
return fetch(`/api/${path}`, {
method,
headers: {
'Content-Type': 'application/json',
Authorization: `Bearer ${accessToken}`,
},
})
.then((response) => {
if (!response.ok) {
throw `Server error: [${response.status}] [${response.statusText}] [${response.url}]`;
}
return response.json();
})
.then((receivedJson) => {
if (receivedJson.status === 'error') {
// Automatically signout user if accessToken is no longer valid
if (receivedJson.code === 'auth/invalid-user-token') {
firebase.auth().signOut();
}
throw new CustomError(receivedJson.code, receivedJson.message);
} else {
return receivedJson.data;
}
})
.catch((err) => {
console.debug('Error in fetch', err);
throw err;
});
}
Additionally, this is what the lambda function (using next API folder) looks like,
const requireAuth = require('../../_require-auth');
const { db } = require('../../_sql');
export default requireAuth(async (req, res) => {
const { uid: id } = req.user;
const startTime = Math.round(req.query.startTime * 0.001);
const endTime = Math.round(req.query.endTime * 0.001);
const parameters = [id, startTime, endTime];
//sql injection definitely possible here, need to work out better method of dealing with this.
const sqlText = `SELECT a,b,c,d,e,f,g,h,i FROM tablename WHERE a=$1 AND i BETWEEN $2 AND $3;`;
try {
const { rows } = await db.query(sqlText, parameters);
return res.status(200).json({
code: 0,
data: rows,
});
} catch (error) {
return res.status(200).json({
code: 0,
message: 'Error occurred in getting tablename',
error,
});
}
});
using postman with the same query, i.e.,
curl --location --request GET 'http://localhost:3000/api/dashboard/expression/get-expression-analytics?startTime=1648387240382&endTime=1651069240382' \
--header 'Authorization: Bearer xxxx' \
--data-raw ''
Successfully returns a response with data attached.
Based on your first code blocks, the startDate value is getting passed into the fetcher as method, and the endDate value is getting passed into the fetcher as data. This is based on the useSWR docs about passing in an array for the key argument: https://swr.vercel.app/docs/arguments#multiple-arguments
If the code you provided is correct, I'd assume the 400 is coming from trying to pass in a random value for the method option for fetch.
This should be fixed by only passing the API endpoint path into useSWR instead of an array:
const { data: expressionsData, error: expressionsError } = useSWRImmutable(
`dashboard/expression/get-expression-analytics?startTime=${startDate}&endTime=${endDate}`,
apiRequest
);

Refactor from fetch to await that can yield same result

So I moved over a non-reusable fetch request code snippet to my API:
let response = await fetch(visitURL, {
method: 'POST',
headers: {
'Content-Type': 'application/json',
'Authorization': 'Bearer ' + userJWT
},
body: JSON.stringify(endingVisit)
});
if (response.ok) {
let {visitId, createdAt} = await response.json();
const viewVisitDto = new ViewVisitDto(`${visitId}${createdAt}${visitorId}${doctorId}${oldPatientId}`);
return viewVisitDto;
} else {
throw new Error("deactivated!")
}
I was able to get this far:
axios.post(visitURL, {
headers,
body: JSON.stringify(visit)
}).then((response) => {
console.log(response);
}).catch((error) => {
console.log(error);
})
But does not exactly give me the visitId and createdAt from the response and I cannot use a response.ok nor a response.json(). Essentially I need to pull out that visitId and createdAt that should be coming back in the response.
I also tried just using node-fetch library, but although in VS code it seems to accept it, TypeScript is not happy with it even when I do install #types/node-fetch and even when I create a type definition file for it, my API just doesn't like it.
Guessing what you are after is
// don't know axios, but if it returns a promise await it
const dto = await axios.post(visitURL, {
headers,
body: JSON.stringify(visit)
}).then((response) => {
// parse response
return {resonse.visitId, resonse.createdAt}
}).then(({visitId, createdAt}) => {
// form dto (where are other vals)?
return new ViewVisitDto(`${visitId}${createdAt}${visitorId}${doctorId}${oldPatientId}`);
}).catch((error) => {
console.log(error);
})
However - you don't mention where doctorId and oldPatientId come from... You try providing more info, including output of the console.log's and the surrounding code

How to handle async fetch undesired result?

I have the following React Native client code:
confirmMatchRecord(userId, matchedUserData['userId'], matchRecordData['matchRecord']['matchWinner'], matchRecordData['matchType'], currentUserRating, matchedUserRating, matchData['_id'], matchRecordData['matchRecord']['_id'], airbnbRatingValue, true, new Date())
.then((results) => {
// Do stuff
})
.catch((error) => {
Alert.alert('Error', 'There was an issue with confirming the record. Please check your connection and/or try again later.');
});
And the following code in my confirmMatchRecord function:
export async function confirmMatchRecord(userId, matchedUserId, matchWinner, matchType, currentUserRating, matchedUserRating, matchId, matchRecordId, matchRating, matchConfirmed, timestamp) {
console.log('Attempting to record match');
info = { userId, matchedUserId, matchWinner, matchType, currentUserRating, matchedUserRating, matchId, matchRecordId, matchRating, matchConfirmed, timestamp }
const firebaseIdToken = await AsyncStorage.getItem('#firebaseIdToken')
const requestOptions = {
method: 'POST',
headers: { 'Content-Type': 'application/json', 'Authorization': 'Bearer ' + firebaseIdToken },
body: JSON.stringify(info)
};
const response = await fetch(ngrokOrLocalhost + '/confirmmatchrecord', requestOptions)
if (response['Status']==='Failure') {
// throw new Error(`HTTP error! status: ${response.status}`);
throw new Error(400);
} else if (response['Status']==='Success') {
const data = await response.json()
return data
}
}
Server code:
router.post('/confirmmatchrecord', async (req, res) => {
// Do a lot of stuff
if (response==='Success') {
return res.status(200).json({'Status': 'Success'})
} else {
return res.status(400).json({'Status': 'Failure'})
console.log('Match record was not confirmed successfully');
}
When response['Status']==='Failure (sent by server) it throws an error 400 as you can see, I was hoping to trigger the .catch in the client code then. But that does not happen, because the client code continues to run on the .then part.
How should I do this instead? Not sure if using .catch here is even correct or if I should do this type of work another way.
You seem to be aware of the bit of a footgun in the fetch API (I write about it here) where fetch only rejects its promise on network errors, not HTTP errors, but your check is incorrect in a couple of ways:
It's status, not Status (capitalization matters), and
It's the HTTP code (400 for instance), not a string
The Response object provides a convenient ok flag that's true for any successful response and false otherwise, so:
const response = await fetch(ngrokOrLocalhost + '/confirmmatchrecord', requestOptions)
if (!response.ok) {
throw new Error(`HTTP error! status: ${response.status}`); // This will be "HTTP error! status: 400" if the HTTP error code is 400
}
const data = await response.json();
return data;
In a comment you've said:
My response['Status'] was checking for a custom server message I had sent (res.status(400).json({'Status': 'Failure'}), I updated the post with it. Not sure why it didn't catch that
Ah! Okay. The reason it didn't catch it is that you're looking for it on the Response object, but your JSON is in the response body.
I suspect you don't want to use your own Status anymore since you know about response.ok and response.status now, but if you ever do want to include your own information in an error response as JSON, you can do that. You'd do it like this:
const response = await fetch(ngrokOrLocalhost + '/confirmmatchrecord', requestOptions)
const data = await response.json(); // Expects JSON in *both* the success response and the error response
if (data.Status === "Failure") {
throw new Error(`HTTP error! status: ${response.status}`); // This will be "HTTP error! status: 400" if the HTTP error code is 400
}
return data;
But I'd stick with just the built-in ok and status for pure success/failure information. This could be handy if you wanted to provide more details of the failure, though.

Vue SPA retrieve status code on error codes (not 200) in nested promise

In my VUE components, I use this async method to fetch data from API:
Components:
methods: {
async fetch() {
// console.log("##### WAIT ####");
const { data } = await staffRepository.getItems(this.teamId)
// console.log("##### END WAIT ####");
this.staffs = data
},
},
As you can see I use a custom repository to have a single axios code, this repository is imported in my previous component.
staffRepository:
export default {
getItems(nationId) {
return Repository.get(`page/${nationId}`)
},
}
And finally the main repository having the axios code:
Repository:
import axios from 'axios/index'
const baseDomain = 'https://my end point'
const baseURL = `${baseDomain}`
...
const headers = {
'X-CSRF-TOKEN': token,
// 'Access-Control-Allow-Origin': '*', // IF you ADD it add 'allowedHeaders' to ai server config/cors.php
'X-Requested-With': 'XMLHttpRequest',
'Content-Type': 'application/json',
Authorization: `Bearer ${jwtoken}`,
}
export default axios.create({
baseURL,
withCredentials: withCredentials,
headers: headers,
})
This code works very nice when the jwtoken is a valid and NOT EXIPRED token.
The problem is when the token is expired or not found and my laravel 5.8 API returns the status code 401 (or other).
GET https://api.endpoint 401 (Unauthorized)
A good solution could catch the status code in staffRepository, the one having the get method.
MySolution: (not working)
getItems(nationId) {
return Repository.get(`page/${nationId}`)
.then(response => {
console.log(response)
})
.catch(error => {
console.log(error.response.status) // <-- it works!
})
},
This could be nice because in error case the error in console is 401
But I can't use this solution because I have 2 nested promises: this one and the async fetch() into the component.
How can I fix it still using my repository environment?
I would suggest using the returned promise in your component, to make things more explicit:
methods: {
fetch() {
let data = null
staffRepository
.getItems(this.teamId)
.then(data => {
// do something with data
this.staffs = data
})
.catch(e => {
// do something with error, or tell the user
})
},
},
Edit - this will work perfectly fine, as your method in Repository will return a promise by default if you are using axios.
Try this: API code, where HTTP is an axios instance
export const get = (path: string): Promise<any> => {
return new Promise((resolve, reject) => {
HTTP.get(`${path}`)
.then((response) => {
resolve(response);
})
.catch((error) => {
reject(handleError(error));
});
});
};
// ***** Handle errors *****/
export function handleError(error) {
if (error.response) {
const status = error.response.status;
switch (status) {
case 400:
// do something
break;
case 401:
// do something, maybe log user out
break;
case 403:
break;
case 500:
// server error...
break;
default:
// handle normal errors here
}
}
return error; // Return the error message, or whatever you want to your components/vue files
}
The best practice solution is to use axios's interceptors:
import axios from "axios";
import Cookies from "js-cookie";
export default (options = {}) => {
let client = options.client || axios.create({ baseURL: process.env.baseUrl });
let token = options.token || Cookies.get("token");
let refreshToken = options.refreshToken || Cookies.get("refreshToken");
let refreshRequest = null;
client.interceptors.request.use(
config => {
if (!token) {
return config;
}
const newConfig = {
headers: {},
...config
};
newConfig.headers.Authorization = `Bearer ${token}`;
return newConfig;
},
e => Promise.reject(e)
);
client.interceptors.response.use(
r => r,
async error => {
if (
!refreshToken ||
error.response.status !== 401 ||
error.config.retry
) {
throw error;
}
if (!refreshRequest) {
refreshRequest = client.post("/auth/refresh", {
refreshToken
});
}
const { data } = await refreshRequest;
const { token: _token, refreshToken: _refreshToken } = data.content;
token = _token;
Cookies.set("token", token);
refreshRequest = _refreshToken;
Cookies.set("refreshToken", _refreshToken);
const newRequest = {
...error.config,
retry: true
};
return client(newRequest);
}
);
return client;
};
Take a look at client.interceptors.response.use. Also you should have a refreshToken. We are intercepting 401 response and sending post request to refresh our token, then waiting for a new fresh token and resending our previous request. It's very elegant and tested solution that fits my company needs, and probably will fit your needs too.
To send request use:
import api from './api'
async function me() {
try {
const res = await api().get('/auth/me')
// api().post('/auth/login', body) <--- POST
if (res.status === 200) { alert('success') }
} catch(e) {
// do whatever you want with the error
}
}
Refresh token: The refresh token is used to generate a new access
token. Typically, if the access token has an expiration date, once it
expires, the user would have to authenticate again to obtain an access
token. With refresh token, this step can be skipped and with a request
to the API get a new access token that allows the user to continue
accessing the application resources.

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