fix: add mayurkale22 recommendations

packages/opentelemetry-exporter-zipkin/src/utils.ts

@@ -0,0 +1,17 @@
+/*!
+ * Copyright 2019, OpenTelemetry Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+export const OT_HEADER_NAME = 'x-opentelemetry-outgoing-request';

packages/opentelemetry-exporter-zipkin/src/zipkin.ts

@@ -31,13 +31,12 @@ import {
   statusCodeTagName,
   statusDescriptionTagName,
 } from './transform';
-
+import { OT_HEADER_NAME } from './utils';
 /**
  * Zipkin Exporter
  */
 export class ZipkinExporter implements SpanExporter {
   static readonly DEFAULT_URL = 'http://localhost:9411/api/v2/spans';
-  static readonly OT_HEADER_NAME = 'x-opentelemetry-outgoing-request';
   private readonly _forceFlush: boolean;
   private readonly _logger: types.Logger;
   private readonly _serviceName: string;
@@ -56,7 +55,7 @@ export class ZipkinExporter implements SpanExporter {
         method: 'POST',
         headers: {
           'Content-Type': 'application/json',
-          [ZipkinExporter.OT_HEADER_NAME]: 1,
+          [OT_HEADER_NAME]: 1,
         },
       },
       urlOpts

packages/opentelemetry-exporter-zipkin/test/zipkin.test.ts

@@ -21,6 +21,7 @@ import { NoopLogger, hrTimeToMilliseconds } from '@opentelemetry/core';
 import * as types from '@opentelemetry/types';
 import { ZipkinExporter } from '../src';
 import * as zipkinTypes from '../src/types';
+import { OT_HEADER_NAME } from '../src/utils';
 
 const MICROS_PER_MILLI = 1000;
 
@@ -242,11 +243,11 @@ describe('ZipkinExporter', () => {
       });
     });
 
-    it(`should send '${ZipkinExporter.OT_HEADER_NAME}' header`, () => {
+    it(`should send '${OT_HEADER_NAME}' header`, () => {
       const scope = nock('https://localhost:9411')
         .post('/api/v2/spans')
         .reply(function(uri, requestBody, cb) {
-          assert.ok(this.req.headers[ZipkinExporter.OT_HEADER_NAME]);
+          assert.ok(this.req.headers[OT_HEADER_NAME]);
           cb(null, [200, 'Ok']);
         });