Async function returns [object Object] instead of value

Question

In calling an async function, I am expecting it to return a JSON payload so I can extract a value from the object. However, the function only returns [object Object]

The async function was being called in a normal function, so I tried changing the parent function to an async function. This helped me because originally I was only getting a value of [object Promise]

Originally, I was attempting this:

const sendRequestToApprover = (userId, announcement, username) => {
  const { title, details, channel } = announcement;

  const channelName = channels.getChannelName(channel);
  console.log('channelName' + channelName);

and getChannelName looks like:

async function getChannelName(id) { 
  try {
    return await api.get('/channels.info', {
      params: { 
        token: botToken,
        channel: id,
      }
    });
  } catch (err) {
    console.log(err);
  }
}

I was able to resolve the issue of getting [object Promise] by making the following change to sendRequestToApprover :

async function sendRequestToApprover(userId, announcement, username) {
  const { title, details, channel } = announcement;

  const channelName = await channels.getChannelName(channel);

  console.log('channelName' + channelName);

Note it is now an async function and I added await to the function call.

I know the payload called by will return the following:

{
    "ok": true,
    "channel": {
        "id": "CJSFDR83T",
        "name": "general",
...
}

I can't quite figure out why I can't get to the name in this case. I've done this in other functions and this one has me stumped. channelName is still returning [object Object] .

Answer 1

When you're doing this:

console.log("channelName" + channelName);

You're calling the toString method on channelName , and on an object this results in [object Object] .

 console.log("Object.toString() -> " + { foo: "bar" }); 

You can avoid this by passing another argument to console.log .

 console.log("Object.toString() -> ", { foo: "bar" }); 

Answer 2

I feel pretty defeated after trying to figure this out this weekend.

I figured this out by assigning the API call to a variable and logging the result.

try {
    const result = await api.get('/channels.info', {
      params: { 
        token: botToken,
        channel: id,
      }
    });

Then I tried logging result and saw the payload! So I updated the function as so:

async function getChannelName(id) { 
  try {
    const result = await api.get('/channels.info', {
      params: { 
        token: botToken,
        channel: id,
      }
    });
    return result.data.channel.name
  } catch (err) {
    console.log(err);
  }
}

Now my channelName variable returns the channel name!