feat!: support Node.js v20 (#78)

BREAKING CHANGE:
Drop support for Node.js v14
Update prom-client to v15
metrics is now an async function

.github/workflows/nodejs-ci-action.yml

@@ -6,14 +6,17 @@ on:
   pull_request:
     branches: [ main ]
 
+env:
+  HUSKY: 0
+
 jobs:
   build:
 
     runs-on: ubuntu-latest
 
     strategy:
       matrix:
-        node-version: [14.x, 16.x, 18.x]
+        node-version: [16.x, 18.x, 20.x, 21.x]
 
     steps:
     - uses: actions/checkout@v2

README.md

@@ -33,7 +33,7 @@ Example:
   prometheus.add([c3]);
 
   // Write metrics to the console
-  console.log(prometheus.metrics);
+  console.log(await prometheus.metrics());
 ```
 
 This module would typically be used in an application that can provide

index.js

@@ -33,11 +33,10 @@ class PrometheusMetrics {
     }
 
     if (!options.registry) {
-      this.interval = this._client
-        .collectDefaultMetrics({
-          prefix: `${this._metricPrefix}opossum_`,
-          timeout: 5000
-        });
+      this._client.collectDefaultMetrics({
+        prefix: `${this._metricPrefix}opossum_`,
+        register: this._registry
+      });
     }
 
     if (options.circuits) {
@@ -75,11 +74,10 @@ class PrometheusMetrics {
   }
 
   clear () {
-    clearInterval(this.interval);
     this._registry.clear();
   }
 
-  get metrics () {
+  metrics () {
     return this._registry.metrics();
   }