forEach & Promise.all() doesn't works - adonis.js

Question

I have a problem with forEach Promise... It doesn't works on AdonisJS.
await Promise.all(items.map(async (item) => {
console.log(item)
}))
No console logged...

Answer 1

I would bet that what the Promise.all return is an empty list, otherwise the console would have logged at least something ^^
Ensure the items object is an iterable object so that Promise.all will not throw an exception
Let's say we test this using adonis cli repl inside your adonis project root so that you can test your application models and also to be sure that your issue does not come from adonis
#!/bin/bash
cd <your adonis project root folder>
adonis repl
# stupid test with a fake iterable object
const MAX_ITEMS = 5
const items = []
for (let i = 0; i < MAX_ITEMS; ++i) {
items.push(i % 2 === 0? i / 2: i * 3 + 1)
}
// let items = []
await Promise.all(items.map(async (item) => {
console.log(item)
return item % 2 === 0 ? item / 2: item * 3 + 1
}))
Now the console would have logged this
0
4
1
10
2
And the result of the Promise.all call would have given this
[ 0, 2, 4, 5, 1 ]
If you use Promise.all without an iterable object you would see some errors (let you test in using adonis repl)
adonis repl
let itemsAsObject = {}
let itemsAsUndefined = undefined
let itemsAsEmptyList = []
async function testPromise(items) {
return Promise.all(items.map(async (item) => {
console.log(item)
return await item % 2 === 0 ? item / 2: item * 3 + 1
}))
}
await testPromise(itemsAsObject) // throws an error
await testPromise(itemsAsUndefined) // throws an error
await testPromise(itemsAsEmptyList) // returns []
You could use the same mechanic with your own Lucid Models
Cheers :)