Async Await issues with NodeJS & AWS Lambda - node.js

Question

I'm currently developing a Lamba function call for my AWS project, but with me not being a master at asynchronous functions it appears it's falling apart, the code I've put together is:
const AWS = require("aws-sdk");
const game = require('game-api');
const uuid = require("uuid");
AWS.config.update({
region: "us-east-1"
});
exports.handler = async (event, context, callback) => {
//set db
var documentClient = new AWS.DynamoDB.DocumentClient()
//params
const params = {
Item: {
'id': uuid.v1(),
'player_1_name': null,
'player_1_network': null,
'player_1_matches': 0,
'player_1_kills': 0,
'player_1_last_updated': 0,
'player_2_name': null,
'player_2_network': null,
'player_2_matches': 0,
'player_2_kills': 0,
'player_2_last_updated': 0,
'match_id': 0,
'status': 0
},
TableName : 'matches'
};
var matchData = JSON.parse(event.body);
//player 1
const player_1_name = matchData.player_1_name ? matchData.player_1_name : null;
const player_1_network = matchData.player_1_network ? matchData.player_1_network : null;
//player 2
const player_2_name = matchData.player_2_name ? matchData.player_2_name : null;
const player_2_network = matchData.player_2_network ? matchData.player_2_network : null;
//match data
const match_id = matchData.match_id ? matchData.match_id : 0;
//game object
let gameAPI = new game(
[
"email#email.com",
"password"
]
);
//gameAPI.login() returns a Promise()
await gameAPI.login().then(() => {
//check stats for player 1, getStats returns a Promise()
gameAPI.getStats(player_1_name, player_1_network).then(stats => {
params.Item.player_1_matches = stats.lifetimeStats.matches;
params.Item.player_1_kills = stats.lifetimeStats.kills;
}).catch(err => {
//error! we must work out what to do here!
console.log(err);
});
//example insert
documentClient.put(params, function(err, data){
return callback(err, data);
});
}).catch(err => {
console.log("We failed to login!");
console.log(err);
});
};
This logic seems flawed since nothing is being thrown to my AWS logs? my idea is to send the request to the function & have it do it as quickly as possible so I can send a 200 response back to Lambda, can anyone point me in the correct direction?

Answer 1

When using async/await you don't need to use callback neither you need to fall into the Promise Hell.
Just await on your promises and grab the result. The great advantage here is it looks as though your code is synchronous.
Here's your refactored code:
const AWS = require("aws-sdk");
const game = require('game-api');
const uuid = require("uuid");
AWS.config.update({
region: "us-east-1"
});
exports.handler = async (event) => {
//set db
var documentClient = new AWS.DynamoDB.DocumentClient()
//params
const params = {
Item: {
'id': uuid.v1(),
'player_1_name': null,
'player_1_network': null,
'player_1_matches': 0,
'player_1_kills': 0,
'player_1_last_updated': 0,
'player_2_name': null,
'player_2_network': null,
'player_2_matches': 0,
'player_2_kills': 0,
'player_2_last_updated': 0,
'match_id': 0,
'status': 0
},
TableName : 'matches'
};
var matchData = JSON.parse(event.body);
//player 1
const player_1_name = matchData.player_1_name ? matchData.player_1_name : null;
const player_1_network = matchData.player_1_network ? matchData.player_1_network : null;
//player 2
const player_2_name = matchData.player_2_name ? matchData.player_2_name : null;
const player_2_network = matchData.player_2_network ? matchData.player_2_network : null;
//match data
const match_id = matchData.match_id ? matchData.match_id : 0;
//game object
let gameAPI = new game(
[
"email#email.com",
"password"
]
);
//gameAPI.login() returns a Promise()
await gameAPI.login()
const stats = await gameAPI.getStats(player_1_name, player_1_network)
params.Item.player_1_matches = stats.lifetimeStats.matches;
params.Item.player_1_kills = stats.lifetimeStats.kills;
//example insert
await documentClient.put(params).promise();
};
If you need to handle the exceptions (you should) just wrap your await calls in try/catch blocks, like this:
try {
console.log(await somePromise)
} catch (e) {
console.log(e)
}
The snippet above is equivalent to:
somePromise.then(console.log).catch(console.log)
with the great difference that you don't need to chain promises/asynchronous code in order to keep the execution order, so I highly recommend you pick the async/await approach and forget about .then().catch()