Make Collections iterable

Currently cannot use code similar to this to loop a Collection:

let dataRows = await MyTable.where({someValue: 7}).fetchAll();
for (let row of dataRows) {
    // do something on row
}

Get: TypeError: dataRows is not iterable

[leebickmtu]

That would be valid in that it would make the awaited Promises within each forEach iteration synchronous. But each iteration would be asynchronous to the main function without a way to await each iteration.

Try this for example. Each iteration will wait for the timeout to resolve back with the row to rowValue then print it. So synchronous within an iteration. But they will print in the order 1,2,3,4 (not the iteration order) because each iteration is asynchronous relative to the others. And you will see ‘after loop’ print before any of them cause the main code can’t await each iteration either.

let dataRows = [2,1,4,3];
dataRows.forEach( async (row) => {
    let rowValue = await new Promise(function(resolve, reject) {
        setTimeout(resolve, row*1000, row);
    });
    console.log(rowValue);
})
console.log('after loop');

[ricardograca]

Duplicate of #1525.