Want to initialize a value from a async call, then keep on using that value, I don't know how to await before node loads other code here.
console.log('---- initialize the value during startup ----');
const p1 = (async () => {
const res = await requestAsync.get('https://nodejs.org/dist/latest-v8.x/docs/api/util.html');
return res.headers;
})();
const v2 = p1.then(v => (v));
console.log(v2);
console.log('---------- more work after v2 is resolved --------------');
i get
---- initialize the value during startup ----
Promise { <pending> }
---------- more work after v2 is resolved --------------
Until node.js has top level await (which it currently doesn't), then the usual way of doing things is to just use .then() and put everything that is dependent upon the asynchronous result inside the .then() handler:
requestAsync.get('https://nodejs.org/dist/latest-v8.x/docs/api/util.html').then(result => {
// put all the rest of your initialization code that
// needs this async result here
}).catch(err => {
// handle errors here
});
If you want to (just for code structure reasons), you can move everything into a function:
requestAsync.get('https://nodejs.org/dist/latest-v8.x/docs/api/util.html')
.then(startup)
.catch(handleErr);
function startup(result) {
// put your startup code here that needs result
}
function handleErr(err) {
// handle error here
}
Keep in mind that any other startup code will continue because module loading does not block waiting for this async result.
If you have multiple asynchronous operations you want do in a row, then you can chain them:
requestAsync.get().then(f1).then(f2).catch(err => {....});
Or, you can wrap code in a top level function so you can use await:
async function startup() {
let result1 = await f1(...);
let result2 = await f2(...);
let result3 = await f3(...);
}
startup().then(finalResult => {
// all async operation done here with finalResult
}).catch(err => {
// error starting up
});
I'm not sure I understand what you mean, but maybe this is what you want?
async function main() {
const response = await requestAsync.get('https://n...');
const headers = response.headers;
console.log('some other stuff here');
}
main();
Putting everything in a "main" function allows you to wait for you initial request before doing anything else.
Be careful though: this is blocking, so if the request takes a while, nothing will happen in your code until it's done.
Related
I wrote this code in lib/helper.js:
var myfunction = async function(x,y) {
....
return [variableA, variableB]
}
exports.myfunction = myfunction;
Then I tried to use it in another file :
var helper = require('./helper.js');
var start = function(a,b){
....
const result = await helper.myfunction('test','test');
}
exports.start = start;
I got an error:
await is only valid in async function
What is the issue?
The error is not refering to myfunction but to start.
async function start() {
....
const result = await helper.myfunction('test', 'test');
}
// My function
const myfunction = async function(x, y) {
return [
x,
y,
];
}
// Start function
const start = async function(a, b) {
const result = await myfunction('test', 'test');
console.log(result);
}
// Call start
start();
I use the opportunity of this question to advise you about an known anti pattern using await which is : return await.
WRONG
async function myfunction() {
console.log('Inside of myfunction');
}
// Here we wait for the myfunction to finish
// and then returns a promise that'll be waited for aswell
// It's useless to wait the myfunction to finish before to return
// we can simply returns a promise that will be resolved later
// useless async here
async function start() {
// useless await here
return await myfunction();
}
// Call start
(async() => {
console.log('before start');
await start();
console.log('after start');
})();
CORRECT
async function myfunction() {
console.log('Inside of myfunction');
}
// Here we wait for the myfunction to finish
// and then returns a promise that'll be waited for aswell
// It's useless to wait the myfunction to finish before to return
// we can simply returns a promise that will be resolved later
// Also point that we don't use async keyword on the function because
// we can simply returns the promise returned by myfunction
function start() {
return myfunction();
}
// Call start
(async() => {
console.log('before start');
await start();
console.log('after start');
})();
Also, know that there is a special case where return await is correct and important : (using try/catch)
Are there performance concerns with `return await`?
To use await, its executing context needs to be async in nature
As it said, you need to define the nature of your executing context where you are willing to await a task before anything.
Just put async before the fn declaration in which your async task will execute.
var start = async function(a, b) {
// Your async task will execute with await
await foo()
console.log('I will execute after foo get either resolved/rejected')
}
Explanation:
In your question, you are importing a method which is asynchronous in nature and will execute in parallel. But where you are trying to execute that async method is inside a different execution context which you need to define async to use await.
var helper = require('./helper.js');
var start = async function(a,b){
....
const result = await helper.myfunction('test','test');
}
exports.start = start;
Wondering what's going under the hood
await consumes promise/future / task-returning methods/functions and async marks a method/function as capable of using await.
Also if you are familiar with promises, await is actually doing the same process of promise/resolve. Creating a chain of promise and executes your next task in resolve callback.
For more info you can refer to MDN DOCS.
When I got this error, it turned out I had a call to the map function inside my "async" function, so this error message was actually referring to the map function not being marked as "async". I got around this issue by taking the "await" call out of the map function and coming up with some other way of getting the expected behavior.
var myfunction = async function(x,y) {
....
someArray.map(someVariable => { // <- This was the function giving the error
return await someFunction(someVariable);
});
}
I had the same problem and the following block of code was giving the same error message:
repositories.forEach( repo => {
const commits = await getCommits(repo);
displayCommit(commits);
});
The problem is that the method getCommits() was async but I was passing it the argument repo which was also produced by a Promise. So, I had to add the word async to it like this: async(repo) and it started working:
repositories.forEach( async(repo) => {
const commits = await getCommits(repo);
displayCommit(commits);
});
If you are writing a Chrome Extension and you get this error for your code at root, you can fix it using the following "workaround":
async function run() {
// Your async code here
const beers = await fetch("https://api.punkapi.com/v2/beers");
}
run();
Basically you have to wrap your async code in an async function and then call the function without awaiting it.
The current implementation of async / await only supports the await keyword inside of async functions Change your start function signature so you can use await inside start.
var start = async function(a, b) {
}
For those interested, the proposal for top-level await is currently in Stage 2: https://github.com/tc39/proposal-top-level-await
async/await is the mechanism of handling promise, two ways we can do it
functionWhichReturnsPromise()
.then(result => {
console.log(result);
})
.cathc(err => {
console.log(result);
});
or we can use await to wait for the promise to full-filed it first, which means either it is rejected or resolved.
Now if we want to use await (waiting for a promise to fulfil) inside a function, it's mandatory that the container function must be an async function because we are waiting for a promise to fulfiled asynchronously || make sense right?.
async function getRecipesAw(){
const IDs = await getIds; // returns promise
const recipe = await getRecipe(IDs[2]); // returns promise
return recipe; // returning a promise
}
getRecipesAw().then(result=>{
console.log(result);
}).catch(error=>{
console.log(error);
});
If you have called async function inside foreach update it to for loop
Found the code below in this nice article: HTTP requests in Node using Axios
const axios = require('axios')
const getBreeds = async () => {
try {
return await axios.get('https://dog.ceo/api/breeds/list/all')
} catch (error) {
console.error(error)
}
}
const countBreeds = async () => {
const breeds = await getBreeds()
if (breeds.data.message) {
console.log(`Got ${Object.entries(breeds.data.message).length} breeds`)
}
}
countBreeds()
Or using Promise:
const axios = require('axios')
const getBreeds = () => {
try {
return axios.get('https://dog.ceo/api/breeds/list/all')
} catch (error) {
console.error(error)
}
}
const countBreeds = async () => {
const breeds = getBreeds()
.then(response => {
if (response.data.message) {
console.log(
`Got ${Object.entries(response.data.message).length} breeds`
)
}
})
.catch(error => {
console.log(error)
})
}
countBreeds()
In later nodejs (>=14), top await is allowed with { "type": "module" } specified in package.json or with file extension .mjs.
https://www.stefanjudis.com/today-i-learned/top-level-await-is-available-in-node-js-modules/
This in one file works..
Looks like await only is applied to the local function which has to be async..
I also am struggling now with a more complex structure and in between different files. That's why I made this small test code.
edit: i forgot to say that I'm working with node.js.. sry. I don't have a clear question. Just thought it could be helpful with the discussion..
function helper(callback){
function doA(){
var array = ["a ","b ","c "];
var alphabet = "";
return new Promise(function (resolve, reject) {
array.forEach(function(key,index){
alphabet += key;
if (index == array.length - 1){
resolve(alphabet);
};
});
});
};
function doB(){
var a = "well done!";
return a;
};
async function make() {
var alphabet = await doA();
var appreciate = doB();
callback(alphabet+appreciate);
};
make();
};
helper(function(message){
console.log(message);
});
A common problem in Express:
The warning can refer to the function, or where you call it.
Express items tend to look like this:
app.post('/foo', ensureLoggedIn("/join"), (req, res) => {
const facts = await db.lookup(something)
res.redirect('/')
})
Notice the => arrow function syntax for the function.
The problem is NOT actually in the db.lookup call, but right here in the Express item.
Needs to be:
app.post('/foo', ensureLoggedIn("/join"), async function (req, res) {
const facts = await db.lookup(something)
res.redirect('/')
})
Basically, nix the => and add async function .
"await is only valid in async function"
But why? 'await' explicitly turns an async call into a synchronous call, and therefore the caller cannot be async (or asyncable) - at least, not because of the call being made at 'await'.
Yes, await / async was a great concept, but the implementation is completely broken.
For whatever reason, the await keyword has been implemented such that it can only be used within an async method. This is in fact a bug, though you will not see it referred to as such anywhere but right here. The fix for this bug would be to implement the await keyword such that it can only be used TO CALL an async function, regardless of whether the calling function is itself synchronous or asynchronous.
Due to this bug, if you use await to call a real asynchronous function somewhere in your code, then ALL of your functions must be marked as async and ALL of your function calls must use await.
This essentially means that you must add the overhead of promises to all of the functions in your entire application, most of which are not and never will be asynchronous.
If you actually think about it, using await in a function should require the function containing the await keyword TO NOT BE ASYNC - this is because the await keyword is going to pause processing in the function where the await keyword is found. If processing in that function is paused, then it is definitely NOT asynchronous.
So, to the developers of javascript and ECMAScript - please fix the await/async implementation as follows...
await can only be used to CALL async functions.
await can appear in any kind of function, synchronous or asynchronous.
Change the error message from "await is only valid in async function" to "await can only be used to call async functions".
I'm trying to learn async/await and your feedback would help a lot.
I'm simply using fs.readFile() as a specific example of functions that has not been modernized with Promises and async/await.
(I'm aware of fs.readFileSync() but I want to learn the concepts.)
Is the pattern below an ok pattern? Are there any issues with it?
const fs = require('fs');
const util = require('util');
//promisify converts fs.readFile to a Promised version
const readFilePr = util.promisify(fs.readFile); //returns a Promise which can then be used in async await
async function getFileAsync(filename) {
try {
const contents = await readFilePr(filename, 'utf-8'); //put the resolved results of readFilePr into contents
console.log('✔️ ', filename, 'is successfully read: ', contents);
}
catch (err){ //if readFilePr returns errors, we catch it here
console.error('⛔ We could not read', filename)
console.error('⛔ This is the error: ', err);
}
}
getFileAsync('abc.txt');
import from fs/promises instead, like this:
const { readFile } = require('fs/promises')
This version returns the promise you are wanting to use and then you don't need to wrap readFile in a promise manually.
Here is some more ways on using async/await
EDITED: as #jfriend00 pointed in comments, of course you have to use standard NodeJS features with built in methods like fs.readFile. So I changed fs method in the code below to something custom, where you can define your own promise.
// Create your async function manually
const asyncFn = data => {
// Instead of result, return promise
return new Promise((resolve, reject) => {
// Here we have two methods: resolve and reject.
// To end promise with success, use resolve
// or reject in opposite
//
// Here we do some task that can take time.
// For example purpose we will emulate it with
// setTimeout delay of 3 sec.
setTimeout(() => {
// After some processing time we done
// and can resolve promise
resolve(`Task completed! Result is ${data * data}`);
}, 3000);
});
}
// Create function from which we will
// call our asyncFn in chain way
const myFunct = () => {
console.log(`myFunct: started...`);
// We will call rf with chain methods
asyncFn(2)
// chain error handler
.catch(error => console.log(error))
// chain result handler
.then(data => console.log(`myFunct: log from chain call: ${data}`));
// Chain call will continue execution
// here without pause
console.log(`myFunct: Continue process while chain task still working.`);
}
// Create ASYNC function to use it
// with await
const myFunct2 = async () => {
console.log(`myFunct2: started...`);
// Read file and wait for result
const data = await asyncFn(3);
// Use your result inline after promise resolved
console.log(`myFunct2: log from async call: ${data}`);
console.log(`myFunct2: continue process after async task completed.`);
}
// Run myFunct
myFunct();
myFunct2();
I wrote this code in lib/helper.js:
var myfunction = async function(x,y) {
....
return [variableA, variableB]
}
exports.myfunction = myfunction;
Then I tried to use it in another file :
var helper = require('./helper.js');
var start = function(a,b){
....
const result = await helper.myfunction('test','test');
}
exports.start = start;
I got an error:
await is only valid in async function
What is the issue?
The error is not refering to myfunction but to start.
async function start() {
....
const result = await helper.myfunction('test', 'test');
}
// My function
const myfunction = async function(x, y) {
return [
x,
y,
];
}
// Start function
const start = async function(a, b) {
const result = await myfunction('test', 'test');
console.log(result);
}
// Call start
start();
I use the opportunity of this question to advise you about an known anti pattern using await which is : return await.
WRONG
async function myfunction() {
console.log('Inside of myfunction');
}
// Here we wait for the myfunction to finish
// and then returns a promise that'll be waited for aswell
// It's useless to wait the myfunction to finish before to return
// we can simply returns a promise that will be resolved later
// useless async here
async function start() {
// useless await here
return await myfunction();
}
// Call start
(async() => {
console.log('before start');
await start();
console.log('after start');
})();
CORRECT
async function myfunction() {
console.log('Inside of myfunction');
}
// Here we wait for the myfunction to finish
// and then returns a promise that'll be waited for aswell
// It's useless to wait the myfunction to finish before to return
// we can simply returns a promise that will be resolved later
// Also point that we don't use async keyword on the function because
// we can simply returns the promise returned by myfunction
function start() {
return myfunction();
}
// Call start
(async() => {
console.log('before start');
await start();
console.log('after start');
})();
Also, know that there is a special case where return await is correct and important : (using try/catch)
Are there performance concerns with `return await`?
To use await, its executing context needs to be async in nature
As it said, you need to define the nature of your executing context where you are willing to await a task before anything.
Just put async before the fn declaration in which your async task will execute.
var start = async function(a, b) {
// Your async task will execute with await
await foo()
console.log('I will execute after foo get either resolved/rejected')
}
Explanation:
In your question, you are importing a method which is asynchronous in nature and will execute in parallel. But where you are trying to execute that async method is inside a different execution context which you need to define async to use await.
var helper = require('./helper.js');
var start = async function(a,b){
....
const result = await helper.myfunction('test','test');
}
exports.start = start;
Wondering what's going under the hood
await consumes promise/future / task-returning methods/functions and async marks a method/function as capable of using await.
Also if you are familiar with promises, await is actually doing the same process of promise/resolve. Creating a chain of promise and executes your next task in resolve callback.
For more info you can refer to MDN DOCS.
When I got this error, it turned out I had a call to the map function inside my "async" function, so this error message was actually referring to the map function not being marked as "async". I got around this issue by taking the "await" call out of the map function and coming up with some other way of getting the expected behavior.
var myfunction = async function(x,y) {
....
someArray.map(someVariable => { // <- This was the function giving the error
return await someFunction(someVariable);
});
}
I had the same problem and the following block of code was giving the same error message:
repositories.forEach( repo => {
const commits = await getCommits(repo);
displayCommit(commits);
});
The problem is that the method getCommits() was async but I was passing it the argument repo which was also produced by a Promise. So, I had to add the word async to it like this: async(repo) and it started working:
repositories.forEach( async(repo) => {
const commits = await getCommits(repo);
displayCommit(commits);
});
If you are writing a Chrome Extension and you get this error for your code at root, you can fix it using the following "workaround":
async function run() {
// Your async code here
const beers = await fetch("https://api.punkapi.com/v2/beers");
}
run();
Basically you have to wrap your async code in an async function and then call the function without awaiting it.
The current implementation of async / await only supports the await keyword inside of async functions Change your start function signature so you can use await inside start.
var start = async function(a, b) {
}
For those interested, the proposal for top-level await is currently in Stage 2: https://github.com/tc39/proposal-top-level-await
async/await is the mechanism of handling promise, two ways we can do it
functionWhichReturnsPromise()
.then(result => {
console.log(result);
})
.cathc(err => {
console.log(result);
});
or we can use await to wait for the promise to full-filed it first, which means either it is rejected or resolved.
Now if we want to use await (waiting for a promise to fulfil) inside a function, it's mandatory that the container function must be an async function because we are waiting for a promise to fulfiled asynchronously || make sense right?.
async function getRecipesAw(){
const IDs = await getIds; // returns promise
const recipe = await getRecipe(IDs[2]); // returns promise
return recipe; // returning a promise
}
getRecipesAw().then(result=>{
console.log(result);
}).catch(error=>{
console.log(error);
});
If you have called async function inside foreach update it to for loop
Found the code below in this nice article: HTTP requests in Node using Axios
const axios = require('axios')
const getBreeds = async () => {
try {
return await axios.get('https://dog.ceo/api/breeds/list/all')
} catch (error) {
console.error(error)
}
}
const countBreeds = async () => {
const breeds = await getBreeds()
if (breeds.data.message) {
console.log(`Got ${Object.entries(breeds.data.message).length} breeds`)
}
}
countBreeds()
Or using Promise:
const axios = require('axios')
const getBreeds = () => {
try {
return axios.get('https://dog.ceo/api/breeds/list/all')
} catch (error) {
console.error(error)
}
}
const countBreeds = async () => {
const breeds = getBreeds()
.then(response => {
if (response.data.message) {
console.log(
`Got ${Object.entries(response.data.message).length} breeds`
)
}
})
.catch(error => {
console.log(error)
})
}
countBreeds()
In later nodejs (>=14), top await is allowed with { "type": "module" } specified in package.json or with file extension .mjs.
https://www.stefanjudis.com/today-i-learned/top-level-await-is-available-in-node-js-modules/
This in one file works..
Looks like await only is applied to the local function which has to be async..
I also am struggling now with a more complex structure and in between different files. That's why I made this small test code.
edit: i forgot to say that I'm working with node.js.. sry. I don't have a clear question. Just thought it could be helpful with the discussion..
function helper(callback){
function doA(){
var array = ["a ","b ","c "];
var alphabet = "";
return new Promise(function (resolve, reject) {
array.forEach(function(key,index){
alphabet += key;
if (index == array.length - 1){
resolve(alphabet);
};
});
});
};
function doB(){
var a = "well done!";
return a;
};
async function make() {
var alphabet = await doA();
var appreciate = doB();
callback(alphabet+appreciate);
};
make();
};
helper(function(message){
console.log(message);
});
A common problem in Express:
The warning can refer to the function, or where you call it.
Express items tend to look like this:
app.post('/foo', ensureLoggedIn("/join"), (req, res) => {
const facts = await db.lookup(something)
res.redirect('/')
})
Notice the => arrow function syntax for the function.
The problem is NOT actually in the db.lookup call, but right here in the Express item.
Needs to be:
app.post('/foo', ensureLoggedIn("/join"), async function (req, res) {
const facts = await db.lookup(something)
res.redirect('/')
})
Basically, nix the => and add async function .
"await is only valid in async function"
But why? 'await' explicitly turns an async call into a synchronous call, and therefore the caller cannot be async (or asyncable) - at least, not because of the call being made at 'await'.
Yes, await / async was a great concept, but the implementation is completely broken.
For whatever reason, the await keyword has been implemented such that it can only be used within an async method. This is in fact a bug, though you will not see it referred to as such anywhere but right here. The fix for this bug would be to implement the await keyword such that it can only be used TO CALL an async function, regardless of whether the calling function is itself synchronous or asynchronous.
Due to this bug, if you use await to call a real asynchronous function somewhere in your code, then ALL of your functions must be marked as async and ALL of your function calls must use await.
This essentially means that you must add the overhead of promises to all of the functions in your entire application, most of which are not and never will be asynchronous.
If you actually think about it, using await in a function should require the function containing the await keyword TO NOT BE ASYNC - this is because the await keyword is going to pause processing in the function where the await keyword is found. If processing in that function is paused, then it is definitely NOT asynchronous.
So, to the developers of javascript and ECMAScript - please fix the await/async implementation as follows...
await can only be used to CALL async functions.
await can appear in any kind of function, synchronous or asynchronous.
Change the error message from "await is only valid in async function" to "await can only be used to call async functions".
I have a function for fetching credentials for an external API (oversimplified):
const fetchCredentials= async () => {
return await fetch(/* url and params */);
};
And another one which calls the above and keeps retrying to call if it the response is not ok.
const retryFetchCredentials = (initialDelay = 250): Promise<Credentials | void> => {
return fetchCredentials().then(async res => {
if (res.ok) {
const parsedResponse = await res.json() as Credentials ;
return parsedResponse;
}
else {
// The issue is with this timeout/return:
setTimeout(() => {
return retryFetchCredentials (initialDelay * 2);
}, initialDelay);
}
});
};
My problem is that I don't know how to strongly type the return inside the setTimeOut function, I keep getting a Promise returned in function argument where a void return was expected. error. I have tried several return types for the functionretryFetchCredentials to no avail.
Any clues about how to solve this?
Just removing the return from the the function inside setTimeout should make the error go away without affecting the behavior of the rest of the code.
As a side note, you shouldn't mix async/await with .then for consistency. And if you use async/await whenever possible, your code is going to increase its readability.
The problem I'm having is that Jest is reporting setResultsSpy is being called 0 times when in fact, I know that it is being called. I know this by putting console.log(results) under the const results = await getFileList(data.path); in my code and was able to see results returned.
My guess right now is that try-catch blocks creates a local scope, which is causing those calls to not be registered. If this is true, my question is "how can I test if those methods have been called"?
// test_myFunction.js
test((`myFunction with valid path should return list of files`), () => {
const actions = {
setMsg: () => { },
setButton: () => {},
setResults: () => {},
setAppState: () => {}
};
const setMsgSpy = jest.spyOn(actions, 'setMsg');
const setSubmitButtonStateSpy = jest.spyOn(actions, 'setButton');
const setResultsSpy = jest.spyOn(actions, 'setResults');
const setAppStateSpy = jest.spyOn(actions, 'setAppState');
const returnedFileList = [
'file1.pdf',
'file2.pdf',
'file3.pdf',
];
const requestConfig = {
component: COMPONENTS.myComponent,
request: RequestTypes.REQUEST,
data: {path: 'folder1'},
actions
};
processRequest(requestConfig)
expect(setMsgSpy).toHaveBeenCalledTimes(1);
expect(setMsgSpy)
.toHaveBeenCalledWith('loading');
expect(setButtonSpy).toHaveBeenCalledTimes(1);
expect(setResultsSpy).toHaveBeenCalledTimes(1);
expect(setResultsSpy).toHaveBeenCalledWith(returnedFileList);
expect(setAppStateSpy).toHaveBeenCalledTimes(1);
expect(setAppStateSpy).toHaveBeenCalledWith('confirm');
});
_
// myFunction.js
async function processRequest({
component,
request,
data,
actions,
}){
if (component === COMPONENTS.myComponent) {
const path = data.path.trim();
switch (request) {
case RequestTypes.REQUEST:
actions.setMsg('message');
actions.setButton('disabled');
try {
const results = await getFileList(data.path);
actions.setResults(results);
actions.setAppState('confirm');
} catch (e) {
actions.setError(e);
actions.setAppState('error');
}
}
break;
default:
break;
}
}
The the problem was Jest was failing out of the test before the results from getFileList() execution has completed since getFileList() is an async function.
The solution is for the test to handle the execution asynchronously as per the documentation. There are 4 ways to solve this problem:
Use callbacks
Use .then() and .catch() on the returned promise (see docs on .then() here and .catch() here)
Use .resolves() or .rejects() Jest methods on expect() to let Jest resolve the promise.
Use Async-Await syntax by declaring the test anonymous function as async and using await on processRequest() .
I went with option 4 as I enjoy using async-await syntax. Here's the solution:
// test_myFunction.js
test((`myFunction with valid path should return list of files`), async () => {
//(all of the variables established from above)
await processRequest(requestConfig)
expect(setMsgSpy).toHaveBeenCalledTimes(1);
expect(setMsgSpy)
.toHaveBeenCalledWith('loading');
expect(setButtonSpy).toHaveBeenCalledTimes(1);
expect(setResultsSpy).toHaveBeenCalledTimes(1);
expect(setResultsSpy).toHaveBeenCalledWith(returnedFileList);
expect(setAppStateSpy).toHaveBeenCalledTimes(1);
expect(setAppStateSpy).toHaveBeenCalledWith('confirm');
});
Notice async being used on the first line and await when calling processRequest(requestConfig).