chore: Fix lint warnings in propagator-jaeger, propagator-b3, resources, and sdk-metrics-base packages (#2406)

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

Author: alisabzevari

packages/opentelemetry-propagator-b3/src/B3MultiPropagator.ts

@@ -42,7 +42,7 @@ function isValidSampledValue(sampled: TraceFlags | undefined): boolean {
   return sampled === TraceFlags.SAMPLED || sampled === TraceFlags.NONE;
 }
 
-export function parseHeader(header: unknown) {
+function parseHeader(header: unknown) {
   return Array.isArray(header) ? header[0] : header;
 }
 
@@ -93,7 +93,7 @@ function getTraceFlags(
  * Based on: https://github.com/openzipkin/b3-propagation
  */
 export class B3MultiPropagator implements TextMapPropagator {
-  inject(context: Context, carrier: unknown, setter: TextMapSetter) {
+  inject(context: Context, carrier: unknown, setter: TextMapSetter): void {
     const spanContext = trace.getSpanContext(context);
     if (
       !spanContext ||

packages/opentelemetry-propagator-b3/src/B3Propagator.ts

@@ -53,7 +53,7 @@ export class B3Propagator implements TextMapPropagator {
     }
   }
 
-  inject(context: Context, carrier: unknown, setter: TextMapSetter) {
+  inject(context: Context, carrier: unknown, setter: TextMapSetter): void {
     if (isTracingSuppressed(context)) {
       return;
     }

packages/opentelemetry-propagator-b3/src/B3SinglePropagator.ts

@@ -49,7 +49,7 @@ function convertToTraceFlags(samplingState: string | undefined): TraceFlags {
  * Based on: https://github.com/openzipkin/b3-propagation
  */
 export class B3SinglePropagator implements TextMapPropagator {
-  inject(context: Context, carrier: unknown, setter: TextMapSetter) {
+  inject(context: Context, carrier: unknown, setter: TextMapSetter): void {
     const spanContext = trace.getSpanContext(context);
     if (
       !spanContext ||

packages/opentelemetry-propagator-jaeger/src/JaegerPropagator.ts

@@ -55,7 +55,7 @@ export class JaegerPropagator implements TextMapPropagator {
     this._jaegerTraceHeader = customTraceHeader || UBER_TRACE_ID_HEADER;
   }
 
-  inject(context: Context, carrier: unknown, setter: TextMapSetter) {
+  inject(context: Context, carrier: unknown, setter: TextMapSetter): void {
     const spanContext = trace.getSpanContext(context);
     const baggage = propagation.getBaggage(context);
     if (spanContext && isTracingSuppressed(context) === false) {

packages/opentelemetry-resources/src/platform/browser/default-service-name.ts

@@ -14,6 +14,6 @@
  * limitations under the License.
  */
 
-export function defaultServiceName() {
+export function defaultServiceName(): string {
     return 'unknown_service';
-}
+}

packages/opentelemetry-resources/src/platform/node/default-service-name.ts

@@ -14,6 +14,6 @@
  * limitations under the License.
  */
 
-export function defaultServiceName() {
+export function defaultServiceName(): string {
     return `unknown_service:${process.argv0}`;
-}
+}

packages/opentelemetry-sdk-metrics-base/src/BaseObserverMetric.ts

@@ -14,6 +14,7 @@
  * limitations under the License.
  */
 import * as api from '@opentelemetry/api-metrics';
+import { Observation } from '@opentelemetry/api-metrics';
 import { InstrumentationLibrary } from '@opentelemetry/core';
 import { Resource } from '@opentelemetry/resources';
 import { BoundObserver } from './BoundInstrument';
@@ -64,14 +65,14 @@ export abstract class BaseObserverMetric
     return super.getMetricRecord();
   }
 
-  protected _processResults(observerResult: ObserverResult) {
+  protected _processResults(observerResult: ObserverResult): void {
     observerResult.values.forEach((value, labels) => {
       const instrument = this.bind(labels);
       instrument.update(value);
     });
   }
 
-  observation(value: number) {
+  observation(value: number): Observation {
     return {
       value,
       observer: this as BaseObserverMetric,

packages/opentelemetry-sdk-metrics-base/src/BatchObserverResult.ts

@@ -35,7 +35,7 @@ export class BatchObserverResult implements api.BatchObserverResult {
    *     updated
    * @param [callback]
    */
-  onObserveCalled(callback?: () => void) {
+  onObserveCalled(callback?: () => void): void {
     this._callback = callback;
   }
 

packages/opentelemetry-sdk-metrics-base/src/CounterMetric.ts

@@ -48,7 +48,7 @@ export class CounterMetric extends Metric<BoundCounter> implements api.Counter {
    * @param [labels = {}] key-values pairs that are associated with a specific metric
    *     that you want to record.
    */
-  add(value: number, labels: api.Labels = {}) {
+  add(value: number, labels: api.Labels = {}): void {
     this.bind(labels).add(value);
   }
 }

packages/opentelemetry-sdk-metrics-base/src/MeterProvider.ts

@@ -54,6 +54,7 @@ export class MeterProvider implements api.MeterProvider {
       );
     }
 
+    // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
     return this._meters.get(key)!;
   }