fix: prefer globalThis instead of window to support webworkers (#2465)

* fix: prefer globalThis instead of window to support webworkers

There is no `window` in either WebWorkers and ServiceWorkers.

* Update packages/opentelemetry-core/test/platform/browser/environment.test.ts

* fixup! add globalThis helpers

experimental/packages/opentelemetry-api-metrics/src/platform/browser/globalThis.ts

@@ -14,6 +14,22 @@
  * limitations under the License.
  */
 
+// Updates to this file should also be replicated to @opentelemetry/api and
+// @opentelemetry/core too.
+
+/**
+ * - globalThis (New standard)
+ * - self (Will return the current window instance for supported browsers)
+ * - window (fallback for older browser implementations)
+ * - global (NodeJS implementation)
+ * - <object> (When all else fails)
+ */
+
 /** only globals that common to node and browsers are allowed */
 // eslint-disable-next-line node/no-unsupported-features/es-builtins, no-undef
-export const _globalThis = typeof globalThis === 'object' ? globalThis : window;
+export const _globalThis: typeof globalThis =
+  typeof globalThis === 'object' ? globalThis :
+  typeof self === 'object' ? self :
+  typeof window === 'object' ? window :
+  typeof global === 'object' ? global :
+  {} as typeof globalThis;

packages/opentelemetry-core/src/platform/browser/environment.ts

@@ -20,12 +20,12 @@ import {
   RAW_ENVIRONMENT,
   parseEnvironment,
 } from '../../utils/environment';
+import { _globalThis } from './globalThis';
 
 /**
  * Gets the environment variables
  */
 export function getEnv(): Required<ENVIRONMENT> {
-  const _window = window as typeof window & RAW_ENVIRONMENT;
-  const globalEnv = parseEnvironment(_window);
+  const globalEnv = parseEnvironment(_globalThis as typeof globalThis & RAW_ENVIRONMENT);
   return Object.assign({}, DEFAULT_ENVIRONMENT, globalEnv);
 }

packages/opentelemetry-core/src/platform/browser/globalThis.ts

@@ -0,0 +1,35 @@
+/*
+ * Copyright The 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.
+ */
+
+// Updates to this file should also be replicated to @opentelemetry/api and
+// @opentelemetry/api-metrics too.
+
+/**
+ * - globalThis (New standard)
+ * - self (Will return the current window instance for supported browsers)
+ * - window (fallback for older browser implementations)
+ * - global (NodeJS implementation)
+ * - <object> (When all else fails)
+ */
+
+/** only globals that common to node and browsers are allowed */
+// eslint-disable-next-line node/no-unsupported-features/es-builtins, no-undef
+export const _globalThis: typeof globalThis =
+  typeof globalThis === 'object' ? globalThis :
+  typeof self === 'object' ? self :
+  typeof window === 'object' ? window :
+  typeof global === 'object' ? global :
+  {} as typeof globalThis;

packages/opentelemetry-core/src/platform/browser/index.ts

@@ -15,6 +15,7 @@
  */
 
 export * from './environment';
+export * from './globalThis';
 export * from './hex-to-base64';
 export * from './RandomIdGenerator';
 export * from './performance';

packages/opentelemetry-core/src/platform/node/globalThis.ts

@@ -0,0 +1,19 @@
+/*
+ * Copyright The 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.
+ */
+
+/** only globals that common to node and browsers are allowed */
+// eslint-disable-next-line node/no-unsupported-features/es-builtins
+export const _globalThis = typeof globalThis === 'object' ? globalThis : global;

packages/opentelemetry-core/src/platform/node/index.ts

@@ -15,6 +15,7 @@
  */
 
 export * from './environment';
+export * from './globalThis';
 export * from './hex-to-base64';
 export * from './RandomIdGenerator';
 export * from './performance';

packages/opentelemetry-core/test/platform/browser/environment.test.ts

@@ -0,0 +1,25 @@
+/*
+ * Copyright The 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.
+ */
+
+import * as assert from 'assert';
+import { getEnv } from '../../../src/platform/browser/environment';
+
+describe('getEnv', () => {
+  it('get environments variables in a browser', () => {
+    const env = getEnv();
+    assert.strictEqual(typeof env, 'object');
+  });
+});