From c86e09a63c2c4e6ea156e9d38ee8cbb00d2fa5ff Mon Sep 17 00:00:00 2001
From: Vlad Golubev <golubev.vld@gmail.com>
Date: Fri, 6 Jan 2017 20:33:33 +0200
Subject: [PATCH] Refactor calculating metrics counts

---
 lib/plugins/aws/metrics/awsMetrics.js | 42 +++++++++------------------
 1 file changed, 13 insertions(+), 29 deletions(-)

diff --git a/lib/plugins/aws/metrics/awsMetrics.js b/lib/plugins/aws/metrics/awsMetrics.js
index 070e7158c..7b9f3fa85 100644
--- a/lib/plugins/aws/metrics/awsMetrics.js
+++ b/lib/plugins/aws/metrics/awsMetrics.js
@@ -6,13 +6,6 @@ const _ = require('lodash');
 const moment = require('moment');
 const validate = require('../lib/validate');
 
-// helper functions
-const getRoundedAvgDuration = (duration, functionsCount) =>
-(Math.round(duration * 100) / 100) / functionsCount;
-
-const reduceDatapoints = (datapoints, statistic) => datapoints
-  .reduce((previous, datapoint) => previous + datapoint[statistic], 0);
-
 class AwsMetrics {
   constructor(serverless, options) {
     this.serverless = serverless;
@@ -190,33 +183,24 @@ class AwsMetrics {
     message += `${formattedStartTime} - ${formattedEndTime}\n\n`;
 
     if (metrics && metrics.length > 0) {
-      let invocations = 0;
-      let throttles = 0;
-      let errors = 0;
-      let duration = 0;
+      const getDatapointsByLabel = (Label) => {
+        return _.chain(metrics).flatten().filter({ Label }).map('Datapoints').flatten().value();
+      };
+
+      const invocationsCount = _.sumBy(getDatapointsByLabel('Invocations'), 'Sum');
+      const throttlesCount = _.sumBy(getDatapointsByLabel('Throttles'), 'Sum');
+      const errorsCount = _.sumBy(getDatapointsByLabel('Errors'), 'Sum');
+      const durationAverage = _.meanBy(getDatapointsByLabel('Duration'), 'Average');
 
-      _.forEach(metrics, (metric) => {
-        _.forEach(metric, (funcMetric) => {
-          if (funcMetric.Label === 'Invocations') {
-            invocations += reduceDatapoints(funcMetric.Datapoints, 'Sum');
-          } else if (funcMetric.Label === 'Throttles') {
-            throttles += reduceDatapoints(funcMetric.Datapoints, 'Sum');
-          } else if (funcMetric.Label === 'Errors') {
-            errors += reduceDatapoints(funcMetric.Datapoints, 'Sum');
-          } else {
-            duration += reduceDatapoints(funcMetric.Datapoints, 'Average');
-          }
-        });
-      });
-      const formattedDuration = `${getRoundedAvgDuration(duration, metrics.length)}ms`;
       // display the data
-      message += `${chalk.yellow('Invocations:', invocations, '\n')}`;
-      message += `${chalk.yellow('Throttles:', throttles, '\n')}`;
-      message += `${chalk.yellow('Errors:', errors, '\n')}`;
-      message += `${chalk.yellow('Duration (avg.):', formattedDuration)}`;
+      message += `${chalk.yellow('Invocations:', invocationsCount, '\n')}`;
+      message += `${chalk.yellow('Throttles:', throttlesCount, '\n')}`;
+      message += `${chalk.yellow('Errors:', errorsCount, '\n')}`;
+      message += `${chalk.yellow('Duration (avg.):', `${durationAverage}ms`)}`;
     } else {
       message += `${chalk.yellow('There are no metrics to show for these options')}`;
     }
+
     this.serverless.cli.consoleLog(message);
     return BbPromise.resolve(message);
   }