I have a function that would return a promise, and in the case of an error, I have to call the same function again. The problem is that whenever I call it again, I get the same response, as if it was never called again.
This is how am resolving:
first_file = async () => {
return new Promise(async (resolve, reject) => {
//Generating the token
(async () => {
while (true) {
console.log("Resolving...");
resolve(token);
await sleep(5000);
resolved_token = token;
}
})();
});
};
I'm generating a token here, which I use in the second script:
function sleep(ms) {
return new Promise((resolve) => {
setTimeout(resolve, ms);
});
}
(async() =>{
while(true){
test = require("./test")
test.first_file ().then(res=>{
console.log(res)
})
await sleep(15000)
}
})()
The expected value here is that every 15000ms (15 sec) I get a new response, but here I'm getting the same response over and over again.
Sorry if the title is inaccurate; I didn't know how to explain the problem.
Promises represent a value + time, a promise's settled value doesn't change like the number 5 doesn't change. Calling resolve multiple times is a no-op*.
What you want to do instead of using the language's abstraction for value + time is to use the language's abstraction for action + time - an async function (or just a function returning a promise)
const tokenFactory = () => {
let current = null;
(async () =>
while (true) {
console.log("Resolving...");
current = token; // get token somewhere
await sleep(5000);
}
})().catch((e) => {/* handle error */});
return () => current; // we return a function so it's captured
};
Which will let you do:
tokenFactory(); // first token (or null)
// 5 seconds later
tokenFactory(); // second token
*We have a flag we added in Node.js called multipleResolves that will let you observe that for logging/error handling