require-await

An async function with no await does nothing asynchronous, but it still wraps its result in a promise, so every caller has to await it. Often the await was removed in a refactor and the async stayed, or an await is missing.

for await and await using count as awaiting. Functions with an empty body and async generators aren't reported. An await in a nested function doesn't count for the outer one.

The report comes with a suggestion that removes async. Callers then get the value and not a promise, so only --fix-dangerously applies it, not --fix-suggestions.

Configure#

Off by default. To turn it on:

[lint.rules]
"require-await" = "error" # or "warn"

Examples#

async function getUser(id) {
  return cache.get(id);
}

function getUser(id) {
  return cache.get(id);
}

async function loadUser(id) {
  const response = await fetch(`/users/${id}`);
  return response.json();
}

The await here belongs to the callback, so saveAll is reported:

async function saveAll(items) {
  items.forEach(async (item) => {
    await save(item);
  });
}

When not to use it#

An async function turns a thrown error into a rejected promise. If a function needs to return a promise to fit an interface, and you rely on async for that, turn the rule off for it.