I've been trying to get data from an API, a async call is used to parse the data. I've be naively iterating over the responses with forEach, calling await in the forEach function, and wondering why it is not producing the result I expected, i.e. wait for the data to settle.

NG:

async function getData() {
  output = ""
  results.forEach(async (block) => {   
    var b = await abc.parse(block)
    output += b
  })
}

Solution

Use a standard for or for..of to loop over the list:

async function getData() {
  output = ""
  for (const block of results) {
    var b = await abc.parse(block)
    output += b
  }
}