call an asynchronous function for every value in a map, but each function call must only start after the previous call has completed and returned its promise value in javascript

One way to achieve this is to use the async/await syntax along with a for...of loop to iterate over the entries in the map one by one, awaiting the completion of each call before proceeding to the next. Here is an example code snippet:

index.tsx
async function processMapEntries(map, asyncFunc) {
  for (const [key, value] of map.entries()) {
    const result = await asyncFunc(key, value);
    console.log(`Result for ${key}: ${result}`);
  }
}

async function asyncFunction(key, value) {
  // do some async processing using key and value...
  return somePromise;
}

// example usage:
const myMap = new Map([
  ["a", 1],
  ["b", 2],
  ["c", 3],
]);

processMapEntries(myMap, asyncFunction);
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In this example, processMapEntries is an async function that takes a map object and an asynchronous function asyncFunc as parameters. It then iterates over each key-value entry in the map using a for...of loop, each time calling asyncFunc with the key and value as arguments and waiting for it to complete using await. Once the promise returned by asyncFunc is resolved, the result is logged to the console.

Note that the asyncFunc function can return any kind of promise, not just a native Promise object. It could also be a function that takes no arguments and returns a promise based on some external state or data source.