feat(opentelemetry-exporter-prometheus): export PrometheusSerializer (#3034)

Co-authored-by: Valentin Marchaud <[email protected]>

Author: matschaffer

experimental/CHANGELOG.md

@@ -12,6 +12,7 @@ All notable changes to experimental packages in this project will be documented
 
 * feat(opentelemetry-instrumentation-fetch): optionally ignore network events #3028 @gregolsen
 * feat(http-instrumentation): record exceptions in http instrumentation #3008 @luismiramirez
+* feat(opentelemetry-exporter-prometheus): export PrometheusSerializer #3034 @matschaffer
 
 ### :bug: (Bug Fix)
 

experimental/packages/opentelemetry-exporter-prometheus/src/PrometheusSerializer.ts

@@ -179,20 +179,20 @@ export class PrometheusSerializer {
   serialize(resourceMetrics: ResourceMetrics): string {
     let str = '';
     for (const scopeMetrics of resourceMetrics.scopeMetrics) {
-      str += this.serializeScopeMetrics(scopeMetrics);
+      str += this._serializeScopeMetrics(scopeMetrics);
     }
     return str;
   }
 
-  serializeScopeMetrics(scopeMetrics: ScopeMetrics) {
+  private _serializeScopeMetrics(scopeMetrics: ScopeMetrics) {
     let str = '';
     for (const metric of scopeMetrics.metrics) {
-      str += this.serializeMetricData(metric) + '\n';
+      str += this._serializeMetricData(metric) + '\n';
     }
     return str;
   }
 
-  serializeMetricData(metricData: MetricData) {
+  private _serializeMetricData(metricData: MetricData) {
     let name = sanitizePrometheusMetricName(
       escapeString(metricData.descriptor.name)
     );
@@ -218,13 +218,13 @@ export class PrometheusSerializer {
     switch (dataPointType) {
       case DataPointType.SINGULAR: {
         results = metricData.dataPoints
-          .map(it => this.serializeSingularDataPoint(name, metricData.descriptor.type, it))
+          .map(it => this._serializeSingularDataPoint(name, metricData.descriptor.type, it))
           .join('');
         break;
       }
       case DataPointType.HISTOGRAM: {
         results = metricData.dataPoints
-          .map(it => this.serializeHistogramDataPoint(name, metricData.descriptor.type, it))
+          .map(it => this._serializeHistogramDataPoint(name, metricData.descriptor.type, it))
           .join('');
         break;
       }
@@ -236,7 +236,7 @@ export class PrometheusSerializer {
     return `${help}\n${type}\n${results}`.trim();
   }
 
-  serializeSingularDataPoint(name: string, type: InstrumentType, dataPoint: DataPoint<number>): string {
+  private _serializeSingularDataPoint(name: string, type: InstrumentType, dataPoint: DataPoint<number>): string {
     let results = '';
 
     name = enforcePrometheusNamingConvention(name, type);
@@ -252,7 +252,7 @@ export class PrometheusSerializer {
     return results;
   }
 
-  serializeHistogramDataPoint(name: string, type: InstrumentType, dataPoint: DataPoint<Histogram>): string {
+  private _serializeHistogramDataPoint(name: string, type: InstrumentType, dataPoint: DataPoint<Histogram>): string {
     let results = '';
 
     name = enforcePrometheusNamingConvention(name, type);

experimental/packages/opentelemetry-exporter-prometheus/src/index.ts

@@ -15,4 +15,5 @@
  */
 
 export * from './PrometheusExporter';
+export * from './PrometheusSerializer';
 export * from './export/types';

experimental/packages/opentelemetry-exporter-prometheus/test/PrometheusSerializer.test.ts

@@ -27,7 +27,7 @@ import {
   Histogram,
 } from '@opentelemetry/sdk-metrics-base';
 import * as sinon from 'sinon';
-import { PrometheusSerializer } from '../src/PrometheusSerializer';
+import { PrometheusSerializer } from '../src';
 import { mockedHrTimeMs, mockHrTime } from './util';
 
 const attributes = {
@@ -86,7 +86,7 @@ describe('PrometheusSerializer', () => {
         const pointData = metric.dataPoints as DataPoint<number>[];
         assert.strictEqual(pointData.length, 1);
 
-        const result = serializer.serializeSingularDataPoint(metric.descriptor.name, metric.descriptor.type, pointData[0]);
+        const result = serializer['_serializeSingularDataPoint'](metric.descriptor.name, metric.descriptor.type, pointData[0]);
         return result;
       }
 
@@ -129,7 +129,7 @@ describe('PrometheusSerializer', () => {
         const pointData = metric.dataPoints as DataPoint<Histogram>[];
         assert.strictEqual(pointData.length, 1);
 
-        const result = serializer.serializeHistogramDataPoint(metric.descriptor.name, metric.descriptor.type, pointData[0]);
+        const result = serializer['_serializeHistogramDataPoint'](metric.descriptor.name, metric.descriptor.type, pointData[0]);
         return result;
       }
 
@@ -184,7 +184,7 @@ describe('PrometheusSerializer', () => {
         assert.strictEqual(resourceMetrics.scopeMetrics[0].metrics.length, 1);
         const scopeMetrics = resourceMetrics.scopeMetrics[0];
 
-        const result = serializer.serializeScopeMetrics(scopeMetrics);
+        const result = serializer['_serializeScopeMetrics'](scopeMetrics);
         return result;
       }
 
@@ -236,7 +236,7 @@ describe('PrometheusSerializer', () => {
         assert.strictEqual(resourceMetrics.scopeMetrics[0].metrics.length, 1);
         const scopeMetrics = resourceMetrics.scopeMetrics[0];
 
-        const result = serializer.serializeScopeMetrics(scopeMetrics);
+        const result = serializer['_serializeScopeMetrics'](scopeMetrics);
         return result;
       }
 
@@ -284,7 +284,7 @@ describe('PrometheusSerializer', () => {
       const pointData = metric.dataPoints as DataPoint<number>[];
       assert.strictEqual(pointData.length, 1);
 
-      const result = serializer.serializeSingularDataPoint(metric.descriptor.name, metric.descriptor.type, pointData[0]);
+      const result = serializer['_serializeSingularDataPoint'](metric.descriptor.name, metric.descriptor.type, pointData[0]);
       return result;
     }
 
@@ -323,7 +323,7 @@ describe('PrometheusSerializer', () => {
       const pointData = metric.dataPoints as DataPoint<number>[];
       assert.strictEqual(pointData.length, 1);
 
-      const result = serializer.serializeSingularDataPoint(metric.descriptor.name, metric.descriptor.type, pointData[0]);
+      const result = serializer['_serializeSingularDataPoint'](metric.descriptor.name, metric.descriptor.type, pointData[0]);
       return result;
     }