Checking if a function is executed with the async keyword

Question

Checking if a function is executed with the async keyword

In my vue3 application, I am looking to create a straightforward test that verifies the presence of the updateRoute function with an async declaration in multiple components.

It's worth noting that due to the structure of my current project, isolating this function in a single file for reusability is not feasible.

For example:

const updateRoute = () => { doSomething() }

This should fail.

However, if it is written as:

const updateRoute = async () => { await doSomething() }

the test should succeed.

The specific testing library used (e.g. Jest) is flexible and can vary based on requirements.

javascript vue.js testing jestjs vuejs3

Answer 1

Answer №1

There isn't a foolproof method or justification to identify an async function. When dealing with a function that gives back a promise, the approach is identical to this:

const updateRoute = () => {
  return doSomethig().then(() => {}) // Results in a promise of undefined
}

It's crucial to validate that updateRoute does indeed give a promise, regardless of whether it utilizes async or not. In Jest, you can achieve this by using:

expect(updateRoute()).toEqual(expect.any(Promise));

If there is a requirement for compulsory await, one can manage this by utilizing the ESLint require-await rule.

Answer 2

There isn't a foolproof method or justification to identify an async function. When dealing with a function that gives back a promise, the approach is identical to this:

const updateRoute = () => {
  return doSomethig().then(() => {}) // Results in a promise of undefined
}

It's crucial to validate that updateRoute does indeed give a promise, regardless of whether it utilizes async or not. In Jest, you can achieve this by using:

expect(updateRoute()).toEqual(expect.any(Promise));

If there is a requirement for compulsory await, one can manage this by utilizing the ESLint require-await rule.

Answer 3

Answer №2

Verify whether the function's contructor.name matches with 'AsyncFunction':

const a = async () => {};
const b = () => {}

console.log(a.constructor.name);
console.log(a.constructor.name === 'AsyncFunction');

console.log(b.constructor.name);
console.log(b.constructor.name === 'AsyncFunction');

Answer 4

Verify whether the function's contructor.name matches with 'AsyncFunction':

const a = async () => {};
const b = () => {}

console.log(a.constructor.name);
console.log(a.constructor.name === 'AsyncFunction');

console.log(b.constructor.name);
console.log(b.constructor.name === 'AsyncFunction');

Checking if a function is executed with the async keyword

Answer №1

Answer №2

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