in the for loop, how to get the data asynchronously through mongoose, and how to execute the following commands after all the asynchronous methods are finished.

pseudo code is as follows:

function getData (list) {
    let result = []
    
    list.forEach((item) => {
        if (item.type === 1) {
            //
            result.push(x)
        } elseif (item.type === 2) {
            //
            result.push(y)
        } else {
            //
            result.push(z)
        }
    })
    
    return result
}

function main () {
    // 
    let result = getData (list)
}

after execution, the result data is all empty, mainly due to the fact that the asynchronous task has not yet been executed. How to solve this problem?