Added Apollo Server GraphQL API error message for failed requests (aws#129)

Any expired security tokens or network connectivity errors when querying neptune resulted in a cryptic error message that was not helpful for debugging.

Instead of swallowing errors, added an error catch message with rethrow to ensure that when these errors result it returns a more useful error message that will help with the debugging of the error.

Author: flora-jin

CHANGELOG.md

@@ -70,6 +70,7 @@ permissions and limitations under the License.
   neptune analytics graph and added testing
   documentation ([#113](https://github.com/aws/amazon-neptune-for-graphql/pull/113))
 * Updated query and mutation names to be less graph-specific ([#124](https://github.com/aws/amazon-neptune-for-graphql/pull/124))
+* Improved API error message for failed requests ([#129](https://github.com/aws/amazon-neptune-for-graphql/pull/129)) 
 * Documented custom query to filter nodes by connected nodes'
   properties ([#130](https://github.com/aws/amazon-neptune-for-graphql/pull/130))
 

templates/ApolloServer/neptune.mjs

@@ -34,9 +34,7 @@ export async function resolveEvent(event) {
         if (loggingEnabled) {
             console.error(err);
         }
-        return {
-            "error": [{"message": err}]
-        };
+        throw new Error(`Failed to query Neptune: ${err.message || err}`);
     }
 
 }

templates/queryHttpNeptune.mjs

@@ -71,11 +71,9 @@ export async function queryNeptune(neptuneUrl, resolvedQuery, options = {logging
             return jsonData;
         }
     } catch (err) {
-        console.error("Failed to query neptune")
+        console.error("Failed to query neptune");
         console.error(err);
-        return {
-            "error": [{"message": err}]
-        };
-    }
 
+        throw new Error(`Neptune query failed: ${err.message || err}`);
+    }
 }