refactor: Replace _.flatten with Array.prototype.flat

lib/plugins/aws/deploy/lib/check-for-changes.js

@@ -255,8 +255,9 @@ module.exports = {
     const partition = account.partition;
 
     const functionNames = await this.serverless.service.getAllFunctions();
-    const cloudwatchLogEvents = _.flatten(
-      functionNames.map((functionName) => {
+
+    const cloudwatchLogEvents = functionNames
+      .map((functionName) => {
         const functionObj = this.serverless.service.getFunction(functionName);
         const FunctionName = functionObj.name;
         const events = functionObj.events;
@@ -272,7 +273,7 @@ module.exports = {
             return { FunctionName, functionName, logGroupName, logSubscriptionSerialNumber };
           });
       })
-    );
+      .flat();
 
     const cloudwatchLogEventsMap = _.groupBy(cloudwatchLogEvents, 'logGroupName');
     const logGroupNames = Object.keys(cloudwatchLogEventsMap);

lib/plugins/aws/metrics.js

@@ -113,11 +113,10 @@ class AwsMetrics {
 
     if (metrics && metrics.length > 0) {
       const getDatapointsByLabel = (Label) =>
-        _.flatten(
-          _.flatten(metrics)
-            .filter((metric) => metric.Label === Label)
-            .map((metric) => metric.Datapoints)
-        );
+        metrics
+          .flat(2)
+          .filter((metric) => metric.Label === Label)
+          .map((metric) => metric.Datapoints);
 
       const invocationsCount = _.sumBy(getDatapointsByLabel('Invocations'), 'Sum');
       const throttlesCount = _.sumBy(getDatapointsByLabel('Throttles'), 'Sum');

lib/plugins/aws/package/compile/events/api-gateway/lib/api-keys.js

@@ -43,7 +43,10 @@ module.exports = {
         if (
           _.isObject(apiKeyDefinition) &&
           Array.isArray(usagePlan) &&
-          _.flatten(usagePlan.map((item) => Object.keys(item))).includes(name)
+          usagePlan
+            .map((item) => Object.keys(item))
+            .flat()
+            .includes(name)
         ) {
           keyNumber = 0;
           apiKeyDefinition[name].forEach((key) => {

lib/plugins/aws/package/compile/events/websockets/lib/deployment.js

@@ -6,16 +6,17 @@ const pickWebsocketsTemplatePart = require('./pick-websockets-template-part');
 
 module.exports = {
   compileDeployment() {
-    const dependentResourceIds = _.flatten(
-      this.validated.events.map((event) => {
+    const dependentResourceIds = this.validated.events
+      .map((event) => {
         const result = [];
         if (event.routeResponseSelectionExpression) {
           result.push(this.provider.naming.getWebsocketsRouteResponseLogicalId(event.route));
         }
         result.push(this.provider.naming.getWebsocketsRouteLogicalId(event.route));
         return result;
       })
-    );
+      .flat();
+
     const websocketsTemplatePart = pickWebsocketsTemplatePart(
       this.serverless.service.provider.compiledCloudFormationTemplate,
       this.provider.naming.getWebsocketsApiLogicalId()

lib/plugins/aws/utils/get-s3-objects-from-stacks.js

@@ -1,8 +1,6 @@
 'use strict';
 
-const _ = require('lodash');
-
 module.exports = (stacks, prefix, service, stage) =>
-  _.flatten(stacks).map((entry) => ({
+  stacks.flat().map((entry) => ({
     Key: `${prefix}/${service}/${stage}/${entry.directory}/${entry.file}`,
   }));