fixup! feat(instrumentation): added synchronous gauge

Author: clintonb

api/src/metrics/Metric.ts

@@ -102,7 +102,7 @@ export interface Gauge<
   AttributesTypes extends MetricAttributes = MetricAttributes,
 > {
   /**
-   * Records a measurement. Value of the measurement must not be negative.
+   * Records a measurement.
    */
   record(value: number, attributes?: AttributesTypes, context?: Context): void;
 }

packages/sdk-metrics/test/Instruments.test.ts

@@ -19,25 +19,25 @@ import * as sinon from 'sinon';
 import { InstrumentationScope } from '@opentelemetry/core';
 import { Resource } from '@opentelemetry/resources';
 import {
-  InstrumentType,
-  MeterProvider,
-  MetricReader,
   DataPoint,
   DataPointType,
   Histogram,
+  InstrumentType,
+  MeterProvider,
   MetricDescriptor,
+  MetricReader,
 } from '../src';
 import {
   TestDeltaMetricReader,
   TestMetricReader,
 } from './export/TestMetricReader';
 import {
-  assertMetricData,
   assertDataPoint,
-  commonValues,
+  assertMetricData,
   commonAttributes,
-  defaultResource,
+  commonValues,
   defaultInstrumentationScope,
+  defaultResource,
 } from './util';
 import { ObservableResult, ValueType } from '@opentelemetry/api';
 
@@ -764,6 +764,41 @@ describe('Instruments', () => {
       });
     });
   });
+
+  describe('Gauge', () => {
+    it('should record common values and attributes without exceptions', async () => {
+      const { meter } = setup();
+      const gauge = meter.createGauge('test');
+
+      for (const values of commonValues) {
+        for (const attributes of commonAttributes) {
+          gauge.record(values, attributes);
+        }
+      }
+    });
+
+    it('should record values', async () => {
+      const { meter, cumulativeReader } = setup();
+      const gauge = meter.createGauge('test');
+
+      gauge.record(1, { foo: 'bar' });
+      gauge.record(-1);
+
+      await validateExport(cumulativeReader, {
+        dataPointType: DataPointType.GAUGE,
+        dataPoints: [
+          {
+            attributes: { foo: 'bar' },
+            value: 1,
+          },
+          {
+            attributes: {},
+            value: -1,
+          },
+        ],
+      });
+    });
+  });
 });
 
 function setup() {

packages/sdk-metrics/test/Meter.test.ts

@@ -19,6 +19,7 @@ import * as assert from 'assert';
 import * as sinon from 'sinon';
 import {
   CounterInstrument,
+  GaugeInstrument,
   HistogramInstrument,
   ObservableCounterInstrument,
   ObservableGaugeInstrument,
@@ -88,6 +89,18 @@ describe('Meter', () => {
     });
   });
 
+  describe('createGauge', () => {
+    testWithNames('Gauge', name => {
+      const meterSharedState = new MeterSharedState(
+        new MeterProviderSharedState(defaultResource),
+        defaultInstrumentationScope
+      );
+      const meter = new Meter(meterSharedState);
+      const Gauge = meter.createGauge(name);
+      assert(Gauge instanceof GaugeInstrument);
+    });
+  });
+
   describe('createObservableCounter', () => {
     testWithNames('ObservableCounter', name => {
       const meterSharedState = new MeterSharedState(