From ba183e416e464fa281c5316c25ea35c8485f89fe Mon Sep 17 00:00:00 2001
From: Raymond Feng <enjoyjava@gmail.com>
Date: Thu, 17 Oct 2019 08:44:09 -0700
Subject: [PATCH] chore(extension-metrics): address review comments

---
 .../src/__tests__/acceptance/metrics-push.acceptance.ts      | 4 +---
 .../metrics/src/__tests__/acceptance/metrics.acceptance.ts   | 4 +---
 extensions/metrics/src/metrics.component.ts                  | 4 ++--
 extensions/metrics/src/observers/index.ts                    | 2 +-
 extensions/metrics/src/observers/metrics.observer.ts         | 3 +++
 .../{pushgateway.observer.ts => metrics.push.observer.ts}    | 5 ++++-
 6 files changed, 12 insertions(+), 10 deletions(-)
 rename extensions/metrics/src/observers/{pushgateway.observer.ts => metrics.push.observer.ts} (87%)

diff --git a/extensions/metrics/src/__tests__/acceptance/metrics-push.acceptance.ts b/extensions/metrics/src/__tests__/acceptance/metrics-push.acceptance.ts
index 483aab8f0bec..d72ded8ea9bf 100644
--- a/extensions/metrics/src/__tests__/acceptance/metrics-push.acceptance.ts
+++ b/extensions/metrics/src/__tests__/acceptance/metrics-push.acceptance.ts
@@ -7,9 +7,7 @@ import {RestApplication, RestServerConfig} from '@loopback/rest';
 import {givenHttpServerConfig, supertest} from '@loopback/testlab';
 import {AddressInfo} from 'net';
 import {promisify} from 'util';
-import {MetricsComponent} from '../..';
-import {MetricsBindings} from '../../keys';
-import {MetricsOptions} from '../../types';
+import {MetricsBindings, MetricsComponent, MetricsOptions} from '../..';
 import {PushGateway} from './mock-pushgateway';
 
 const gateway = new PushGateway();
diff --git a/extensions/metrics/src/__tests__/acceptance/metrics.acceptance.ts b/extensions/metrics/src/__tests__/acceptance/metrics.acceptance.ts
index 7eef91ab337b..469bf6e835f3 100644
--- a/extensions/metrics/src/__tests__/acceptance/metrics.acceptance.ts
+++ b/extensions/metrics/src/__tests__/acceptance/metrics.acceptance.ts
@@ -10,9 +10,7 @@ import {
   expect,
   givenHttpServerConfig,
 } from '@loopback/testlab';
-import {MetricsComponent} from '../..';
-import {MetricsBindings} from '../../keys';
-import {MetricsOptions} from '../../types';
+import {MetricsBindings, MetricsComponent, MetricsOptions} from '../..';
 
 describe('Metrics (acceptance)', () => {
   let app: RestApplication;
diff --git a/extensions/metrics/src/metrics.component.ts b/extensions/metrics/src/metrics.component.ts
index 7a07f36a2e62..6e521122976e 100644
--- a/extensions/metrics/src/metrics.component.ts
+++ b/extensions/metrics/src/metrics.component.ts
@@ -15,7 +15,7 @@ import {Application, Component, CoreBindings} from '@loopback/core';
 import {metricsControllerFactory} from './controllers';
 import {MetricsInterceptor} from './interceptors';
 import {MetricsBindings} from './keys';
-import {MetricsObserver, PushGatewayObserver} from './observers';
+import {MetricsObserver, MetricsPushObserver} from './observers';
 import {DEFAULT_METRICS_OPTIONS, MetricsOptions} from './types';
 
 /**
@@ -39,7 +39,7 @@ export class MetricsComponent implements Component {
       !options.pushGateway ||
       (options.pushGateway && !options.pushGateway.disabled)
     ) {
-      this.application.lifeCycleObserver(PushGatewayObserver);
+      this.application.lifeCycleObserver(MetricsPushObserver);
     }
     this.application.add(createBindingFromClass(MetricsInterceptor));
     if (!options.endpoint || (options.endpoint && !options.endpoint.disabled)) {
diff --git a/extensions/metrics/src/observers/index.ts b/extensions/metrics/src/observers/index.ts
index c177bafa36d5..ed69679e9a98 100644
--- a/extensions/metrics/src/observers/index.ts
+++ b/extensions/metrics/src/observers/index.ts
@@ -4,4 +4,4 @@
 // License text available at https://opensource.org/licenses/MIT
 
 export * from './metrics.observer';
-export * from './pushgateway.observer';
+export * from './metrics.push.observer';
diff --git a/extensions/metrics/src/observers/metrics.observer.ts b/extensions/metrics/src/observers/metrics.observer.ts
index 1db72c17d897..aec0669dff0a 100644
--- a/extensions/metrics/src/observers/metrics.observer.ts
+++ b/extensions/metrics/src/observers/metrics.observer.ts
@@ -8,6 +8,9 @@ import {collectDefaultMetrics, register} from 'prom-client';
 import {MetricsBindings} from '../keys';
 import {DEFAULT_METRICS_OPTIONS, MetricsOptions} from '../types';
 
+/**
+ * An observer to set default Node.js metrics collection
+ */
 export class MetricsObserver implements LifeCycleObserver {
   private interval: NodeJS.Timeout | undefined;
 
diff --git a/extensions/metrics/src/observers/pushgateway.observer.ts b/extensions/metrics/src/observers/metrics.push.observer.ts
similarity index 87%
rename from extensions/metrics/src/observers/pushgateway.observer.ts
rename to extensions/metrics/src/observers/metrics.push.observer.ts
index 76f27e45d28f..c14f2bd4e4c3 100644
--- a/extensions/metrics/src/observers/pushgateway.observer.ts
+++ b/extensions/metrics/src/observers/metrics.push.observer.ts
@@ -8,7 +8,10 @@ import {Pushgateway} from 'prom-client';
 import {MetricsBindings} from '../keys';
 import {DEFAULT_METRICS_OPTIONS, MetricsOptions} from '../types';
 
-export class PushGatewayObserver implements LifeCycleObserver {
+/**
+ * An observer to set up periodical push of metrics to a push gateway
+ */
+export class MetricsPushObserver implements LifeCycleObserver {
   private interval: NodeJS.Timeout | undefined;
   private gateway: Pushgateway;