AppSync JavaScript Support for Array.sort of objects

Question

While implementing JS resolvers in AppSync I can't find a way to sort an Array of objects.

```
array_of_objects.sort((a, b) => (a.event_ts - b.event_ts))
```
 is failing with:
"errorType": "UNSUPPORTED_SYNTAX_TYPE",

"value": "Unsupported Syntax Type: ArrowFunction",

```
const compareFn = (a, b) => {
        return (a.event_ts - b.event_ts)
        if ( a.event_ts < b.event_ts ){
            return -1;
          }
          if ( a.event_ts > b.event_ts ){
            return 1;
          }
          return 0;
    };

array_of_objects.sort(compareFn)
```
Doesn't sort the array in place and doesn't return a sorted array (JavaScript is annoying...).

The documentation of AppSync (https://docs.aws.amazon.com/appsync/latest/devguide/built-in-objects-functions.html) mentions that `Array.prototype.sort()` is supported, and indeed, if I pass a simple array (of Strings, for example) it is working OK. However, for objects, I can't get it to work.

Answer

Hi, I would suggest to try this out:

* try, just for experiment, to not use "=>" arrow function but rather a function

```
const compareFn = function(a, b) {
        return (a.event_ts - b.event_ts)
        if ( a.event_ts < b.event_ts ){
            return -1;
          }
          if ( a.event_ts > b.event_ts ){
            return 1;
          }
          return 0;
    };
```
* Alternatively use the "map" function on the array before you call the sort method. (https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/map)

AppSync JavaScript Support for Array.sort of objects

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