Wait for array.map iterations in Promise.all [duplicate]

Question

I have the following code that should add items for customers if they dont already exist. Execution should be in parallel.

await Promise.all(
    customers.map(async (customer) => {
        return customer.items.map(async (item) => {
            return new Promise(async (resolve) => {
                const productExists = someArray.some(
                    (arrayValue) => arrayValue === item.id
                );
                if (!productExists) {
                    logger.info(
                    `customer item ${item.id} does not exist, creating...`
                    );
                    await createCustomerItem(item.id);
                    logger.info(`customer item ${item.id} created.`);

                    someArray.push(item.id);
                } else {
                    logger.info(`customer item ${item.id} already exists, skipping...`);
                }
                resolve(true);
            });
        });
    })

);

logger.info(`All items should now be present`);

The problem is that the execution is not waiting for createCustomerItem to resolve in the cases of !productExists)

This is the log

customer item 32310 does not exist, creating...
customer item ao does not exist, creating...
customer item ute does not exist, creating...
All items should not be present
customer item ao created.
customer item ute created.
customer item 32310 created.

Naturally All items should not be present should come last.

When all the items already exist, then the process looks good.

Answer 1

you can do something like this

const fruitsToGet = ['apple', 'grape', 'pear']

const mapLoop = async () => {
  console.log('Start')

  const promises = await fruitsToGet.map(async fruit => {
    const numFruit = new Promise((resolve, reject) => {
      setTimeout(() => resolve(fruit), 1000)
    });
    return numFruit
  })
  const numFruits = await Promise.all(promises)
  console.log(numFruits)

  console.log('End')
}

mapLoop();

results

Start
["apple", "grape", "pear"]
End

source demo