diff --git a/.github/workflows/unit-test.yml b/.github/workflows/unit-test.yml
index 4cc9daca63..d054a29f93 100644
--- a/.github/workflows/unit-test.yml
+++ b/.github/workflows/unit-test.yml
@@ -81,6 +81,41 @@ jobs:
         run: npm run test:browser
       - name: Report Coverage
         run: npm run codecov:browser
+  webworker-tests-stable:
+    runs-on: ubuntu-latest
+    container:
+      image: circleci/node:14-browsers
+    env:
+      NPM_CONFIG_UNSAFE_PERM: true
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v1
+      - name: Permission Setup
+        run: sudo chmod -R 777 /github /__w
+
+      - name: restore lerna
+        uses: actions/cache@v2
+        id: cache
+        with:
+          path: |
+            node_modules
+            */*/node_modules
+          key: browser-tests-stable-${{ runner.os }}-${{ matrix.node_version }}-${{ hashFiles('**/package.json') }}
+
+      - name: Bootstrap
+        if: steps.cache.outputs.cache-hit != 'true'
+        run: |
+          npm install --ignore-scripts
+          npx lerna bootstrap --no-ci --hoist --nohoist='zone.js'
+
+      - name: Build 🔧
+        run: |
+          npm run compile
+
+      - name: Unit tests
+        run: npm run test:webworker
+      - name: Report Coverage
+        run: npm run codecov:webworker
   node-tests-experimental:
     strategy:
       fail-fast: false
@@ -164,3 +199,42 @@ jobs:
       - name: Report Coverage
         working-directory: experimental
         run: npm run codecov:browser
+  webworker-tests-experimental:
+    runs-on: ubuntu-latest
+    container:
+      image: circleci/node:14-browsers
+    env:
+      NPM_CONFIG_UNSAFE_PERM: true
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v1
+      - name: Permission Setup
+        run: sudo chmod -R 777 /github /__w
+
+      - name: restore lerna
+        uses: actions/cache@v2
+        id: cache
+        with:
+          path: |
+            experimental/node_modules
+            experimental/*/*/node_modules
+          key: browser-tests-experimental-${{ runner.os }}-${{ matrix.node_version }}-${{ hashFiles('**/package.json') }}
+
+      - name: Bootstrap
+        if: steps.cache.outputs.cache-hit != 'true'
+        working-directory: experimental
+        run: |
+          npm install --ignore-scripts
+          npx lerna bootstrap --no-ci --hoist --nohoist='zone.js'
+
+      - name: Build 🔧
+        working-directory: experimental
+        run: |
+          npm run compile
+
+      - name: Unit tests
+        working-directory: experimental
+        run: npm run test:webworker
+      - name: Report Coverage
+        working-directory: experimental
+        run: npm run codecov:webworker
diff --git a/doc/web-api.md b/doc/web-api.md
new file mode 100644
index 0000000000..8d916e5847
--- /dev/null
+++ b/doc/web-api.md
@@ -0,0 +1,21 @@
+# Web API Usages Guidance
+
+The packages of OpenTelemetry that targeting web platforms should be compatible
+with the following web environments:
+
+- [Browsing Context](https://developer.mozilla.org/en-US/docs/Glossary/Browsing_context),
+- [Web Worker](https://developer.mozilla.org/en-US/docs/Web/API/Web_Workers_API/Functions_and_classes_available_to_workers).
+
+As such, the usage of Web API that depends on APIs like [`window`],
+[`document`] and [`navigator`] is discouraged.
+
+If the use of the browsing context API is necessary, like adding `onload`
+listeners, an alternative code path for Web Worker environment should also be
+supported.
+
+It is an exception to above guidance if the package is instrumenting the
+browsing context only.
+
+[`window`]: https://developer.mozilla.org/en-US/docs/Web/API/window
+[`document`]: https://developer.mozilla.org/en-US/docs/Web/API/Document
+[`navigator]: https://developer.mozilla.org/en-US/docs/Web/API/Navigator
diff --git a/experimental/packages/opentelemetry-instrumentation-xml-http-request/.eslintrc.js b/experimental/packages/opentelemetry-instrumentation-xml-http-request/.eslintrc.js
index 6ad6c9f216..b50dfd815b 100644
--- a/experimental/packages/opentelemetry-instrumentation-xml-http-request/.eslintrc.js
+++ b/experimental/packages/opentelemetry-instrumentation-xml-http-request/.eslintrc.js
@@ -1,9 +1,7 @@
 module.exports = {
     "env": {
         "mocha": true,
-        "commonjs": true,
         "browser": true,
-        "jquery": true
     },
     ...require('../../../eslint.config.js')
 }
diff --git a/karma.base.js b/karma.base.js
index cbae813f7b..7df76d7b13 100644
--- a/karma.base.js
+++ b/karma.base.js
@@ -26,6 +26,8 @@ module.exports = {
   },
   reporters: ['spec', 'coverage-istanbul'],
   files: ['test/index-webpack.ts'],
-  preprocessors: { 'test/index-webpack.ts': ['webpack'] },
+  preprocessors: {
+    'test/index-webpack*.ts': ['webpack']
+  },
   webpackMiddleware: { noInfo: true }
 };
diff --git a/karma.worker.js b/karma.worker.js
new file mode 100644
index 0000000000..9a6f9d5eb3
--- /dev/null
+++ b/karma.worker.js
@@ -0,0 +1,27 @@
+/*!
+ * 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
+ *
+ *      http://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.
+ */
+
+const baseConfig = require('./karma.base');
+
+module.exports = {
+  ...baseConfig,
+  frameworks: ['mocha-webworker'],
+
+  files: [{
+    pattern: 'test/index-webpack.worker.ts',
+    included: false,
+  }],
+};
diff --git a/package.json b/package.json
index 693ccde5d6..6798a9a996 100644
--- a/package.json
+++ b/package.json
@@ -16,11 +16,13 @@
     "version:update": "lerna run version:update",
     "test": "lerna run test",
     "test:browser": "lerna run test:browser",
+    "test:webworker": "lerna run test:webworker",
     "test:backcompat": "lerna run test:backcompat",
     "bootstrap": "lerna bootstrap --hoist --nohoist='zone.js'",
     "changelog": "lerna-changelog",
     "codecov": "lerna run codecov",
     "codecov:browser": "lerna run codecov:browser",
+    "codecov:webworker": "lerna run codecov:webworker",
     "predocs-test": "npm run docs",
     "docs": "typedoc && touch docs/.nojekyll",
     "docs-deploy": "gh-pages --dotfiles --dist docs",
diff --git a/packages/opentelemetry-sdk-trace-web/.eslintrc.js b/packages/opentelemetry-sdk-trace-web/.eslintrc.js
index 01b8d09740..86d794e2f5 100644
--- a/packages/opentelemetry-sdk-trace-web/.eslintrc.js
+++ b/packages/opentelemetry-sdk-trace-web/.eslintrc.js
@@ -1,9 +1,7 @@
 module.exports = {
     "env": {
         "mocha": true,
-        "commonjs": true,
         "browser": true,
-        "jquery": true
     },
     ...require('../../eslint.config.js')
 }
diff --git a/packages/opentelemetry-sdk-trace-web/karma.worker.js b/packages/opentelemetry-sdk-trace-web/karma.worker.js
new file mode 100644
index 0000000000..d392e58ba6
--- /dev/null
+++ b/packages/opentelemetry-sdk-trace-web/karma.worker.js
@@ -0,0 +1,24 @@
+/*!
+ * 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
+ *
+ *      http://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.
+ */
+
+const karmaWebpackConfig = require('../../karma.webpack');
+const karmaBaseConfig = require('../../karma.worker');
+
+module.exports = (config) => {
+  config.set(Object.assign({}, karmaBaseConfig, {
+    webpack: karmaWebpackConfig
+  }))
+};
diff --git a/packages/opentelemetry-sdk-trace-web/package.json b/packages/opentelemetry-sdk-trace-web/package.json
index 2e88f6520e..7e6ce6b66f 100644
--- a/packages/opentelemetry-sdk-trace-web/package.json
+++ b/packages/opentelemetry-sdk-trace-web/package.json
@@ -13,9 +13,11 @@
     "lint": "eslint . --ext .ts",
     "lint:fix": "eslint . --ext .ts --fix",
     "codecov:browser": "nyc report --reporter=json && codecov -f coverage/*.json -p ../../",
+    "codecov:webworker": "nyc report --reporter=json && codecov -f coverage/*.json -p ../../",
     "version": "node ../../scripts/version-update.js",
     "tdd": "karma start",
     "test:browser": "nyc karma start --single-run",
+    "test:webworker": "nyc karma start karma.worker.js --single-run",
     "watch": "tsc --build --watch tsconfig.all.json",
     "precompile": "lerna run version --scope $(npm pkg get name) --include-dependencies",
     "prewatch": "npm run precompile"
@@ -69,6 +71,7 @@
     "karma-coverage-istanbul-reporter": "3.0.3",
     "karma-jquery": "0.2.4",
     "karma-mocha": "2.0.1",
+    "karma-mocha-webworker": "1.3.0",
     "karma-spec-reporter": "0.0.32",
     "karma-webpack": "4.0.2",
     "mocha": "7.2.0",
diff --git a/packages/opentelemetry-sdk-trace-web/src/utils.ts b/packages/opentelemetry-sdk-trace-web/src/utils.ts
index 58831f4f21..fc3978abad 100644
--- a/packages/opentelemetry-sdk-trace-web/src/utils.ts
+++ b/packages/opentelemetry-sdk-trace-web/src/utils.ts
@@ -164,7 +164,7 @@ export function getResource(
   }
   const sorted = sortResources(filteredResources);
 
-  if (parsedSpanUrl.origin !== window.location.origin && sorted.length > 1) {
+  if (parsedSpanUrl.origin !== location.origin && sorted.length > 1) {
     let corsPreFlightRequest: PerformanceResourceTiming | undefined = sorted[0];
     let mainRequest: PerformanceResourceTiming = findMainRequest(
       sorted,
@@ -421,7 +421,7 @@ export function shouldPropagateTraceHeaders(
   }
   const parsedSpanUrl = parseUrl(spanUrl);
 
-  if (parsedSpanUrl.origin === window.location.origin) {
+  if (parsedSpanUrl.origin === location.origin) {
     return true;
   } else {
     return propagateTraceHeaderUrls.some(propagateTraceHeaderUrl =>
diff --git a/packages/opentelemetry-sdk-trace-web/test/StackContextManager.test.ts b/packages/opentelemetry-sdk-trace-web/test/StackContextManager.test.ts
index 1509780e7b..8fb1e34d13 100644
--- a/packages/opentelemetry-sdk-trace-web/test/StackContextManager.test.ts
+++ b/packages/opentelemetry-sdk-trace-web/test/StackContextManager.test.ts
@@ -111,7 +111,7 @@ describe('StackContextManager', () => {
         assert.strictEqual(contextManager.active(), ctx1);
         return done();
       });
-      assert.strictEqual(contextManager.active(), window);
+      assert.strictEqual(contextManager.active(), globalThis);
     });
 
     it('should finally restore an old context when context is an object', done => {
@@ -130,7 +130,7 @@ describe('StackContextManager', () => {
         assert.strictEqual(contextManager.active(), ctx1);
         return done();
       });
-      assert.strictEqual(contextManager.active(), window);
+      assert.strictEqual(contextManager.active(), globalThis);
     });
 
     it('should forward this, arguments and return value', () => {
diff --git a/packages/opentelemetry-sdk-trace-web/test/index-webpack.ts b/packages/opentelemetry-sdk-trace-web/test/index-webpack.ts
index 061a48ccfa..e455815ca9 100644
--- a/packages/opentelemetry-sdk-trace-web/test/index-webpack.ts
+++ b/packages/opentelemetry-sdk-trace-web/test/index-webpack.ts
@@ -13,8 +13,13 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-const testsContext = require.context('.', true, /test$/);
-testsContext.keys().forEach(testsContext);
 
-const srcContext = require.context('.', true, /src$/);
-srcContext.keys().forEach(srcContext);
+{
+  const testsContext = require.context('./', false, /test$/);
+  testsContext.keys().forEach(testsContext);
+}
+
+{
+  const testsContext = require.context('./window', false, /test$/);
+  testsContext.keys().forEach(testsContext);
+}
diff --git a/packages/opentelemetry-sdk-trace-web/test/index-webpack.worker.ts b/packages/opentelemetry-sdk-trace-web/test/index-webpack.worker.ts
new file mode 100644
index 0000000000..4ee65b7b12
--- /dev/null
+++ b/packages/opentelemetry-sdk-trace-web/test/index-webpack.worker.ts
@@ -0,0 +1,18 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+const testsContext = require.context('./', false, /test$/);
+testsContext.keys().forEach(testsContext);
diff --git a/packages/opentelemetry-sdk-trace-web/test/utils.test.ts b/packages/opentelemetry-sdk-trace-web/test/utils.test.ts
index b8217e4f13..f870450013 100644
--- a/packages/opentelemetry-sdk-trace-web/test/utils.test.ts
+++ b/packages/opentelemetry-sdk-trace-web/test/utils.test.ts
@@ -27,7 +27,6 @@ import * as sinon from 'sinon';
 import {
   addSpanNetworkEvent,
   addSpanNetworkEvents,
-  getElementXPath,
   getResource,
   normalizeUrl,
   parseUrl,
@@ -48,45 +47,6 @@ function createHrTime(startTime: HrTime, addToStart: number): HrTime {
   }
   return [seconds, nanos];
 }
-const fixture = `
-<div>
-  <div></div>
-  <div></div>
-  <div></div>
-  <div>
-    <div></div>
-    <div>
-    </div>
-    <div id="text">lorep ipsum</div>
-    <div></div>
-    <div class="btn2">
-      foo
-      <button></button>
-      <button></button>
-      <button id="btn22"></button>
-      <button></button>
-      bar
-    </div>
-    <div>
-      aaaaaaaaa
-      <![CDATA[ /*Some code with < & and what not */ ]]>
-      <button id="btn23"></button>
-      bbb
-    </div>
-    <div></div>
-    <div id="comment"></div>
-    <div></div>
-    <div id="cdata">
-      <![CDATA[ /*Some code with < & and what not */ ]]>
-      <![CDATA[ /*Some code with < & and what not */ ]]>
-      <![CDATA[ /*Some code with < & and what not */ ]]>
-      bar
-    </div>
-    <div></div>
-  </div>
-  <div></div>
-</div>
-`;
 
 function createResource(
   resource = {},
@@ -475,92 +435,11 @@ describe('utils', () => {
       });
     });
   });
-  describe('getElementXPath', () => {
-    let $fixture: any;
-    let child: any;
-    before(() => {
-      $fixture = $(fixture);
-      const body = document.querySelector('body');
-      if (body) {
-        body.appendChild($fixture[0]);
-        child = body.lastChild;
-      }
-    });
-    after(() => {
-      child.parentNode.removeChild(child);
-    });
-
-    it('should return correct path for element with id and optimise = true', () => {
-      const element = getElementXPath($fixture.find('#btn22')[0], true);
-      assert.strictEqual(element, '//*[@id="btn22"]');
-      assert.strictEqual(
-        $fixture.find('#btn22')[0],
-        getElementByXpath(element)
-      );
-    });
-
-    it(
-      'should return correct path for element with id and surrounded by the' +
-        ' same type',
-      () => {
-        const element = getElementXPath($fixture.find('#btn22')[0]);
-        assert.strictEqual(element, '//html/body/div/div[4]/div[5]/button[3]');
-        assert.strictEqual(
-          $fixture.find('#btn22')[0],
-          getElementByXpath(element)
-        );
-      }
-    );
-
-    it(
-      'should return correct path for element with id and and surrounded by' +
-        ' text nodes mixed with cnode',
-      () => {
-        const element = getElementXPath($fixture.find('#btn23')[0]);
-        assert.strictEqual(element, '//html/body/div/div[4]/div[6]/button');
-        assert.strictEqual(
-          $fixture.find('#btn23')[0],
-          getElementByXpath(element)
-        );
-      }
-    );
-
-    it(
-      'should return correct path for text node element surrounded by cdata' +
-        ' nodes',
-      () => {
-        const text = $fixture.find('#cdata')[0];
-        const textNode = document.createTextNode('foobar');
-        text.appendChild(textNode);
-        const element = getElementXPath(textNode);
-        assert.strictEqual(element, '//html/body/div/div[4]/div[10]/text()[5]');
-        assert.strictEqual(textNode, getElementByXpath(element));
-      }
-    );
-
-    it('should return correct path when element is text node', () => {
-      const text = $fixture.find('#text')[0];
-      const textNode = document.createTextNode('foobar');
-      text.appendChild(textNode);
-      const element = getElementXPath(textNode);
-      assert.strictEqual(element, '//html/body/div/div[4]/div[3]/text()[2]');
-      assert.strictEqual(textNode, getElementByXpath(element));
-    });
-
-    it('should return correct path when element is comment node', () => {
-      const comment = $fixture.find('#comment')[0];
-      const node = document.createComment('foobar');
-      comment.appendChild(node);
-      const element = getElementXPath(node);
-      assert.strictEqual(element, '//html/body/div/div[4]/div[8]/comment()');
-      assert.strictEqual(node, getElementByXpath(element));
-    });
-  });
 
   describe('shouldPropagateTraceHeaders', () => {
     it('should propagate trace when url is the same as origin', () => {
       const result = shouldPropagateTraceHeaders(
-        `${window.location.origin}/foo/bar`
+        `${globalThis.location.origin}/foo/bar`
       );
       assert.strictEqual(result, true);
     });
@@ -611,14 +490,6 @@ describe('utils', () => {
         assert.strictEqual(typeof url[field], 'string');
       });
     });
-
-    it('should parse url with fallback', () => {
-      sinon.stub(window, 'URL').value(undefined);
-      const url = parseUrl('https://opentelemetry.io/foo');
-      urlFields.forEach(field => {
-        assert.strictEqual(typeof url[field], 'string');
-      });
-    });
   });
 
   describe('normalizeUrl', () => {
@@ -626,21 +497,5 @@ describe('utils', () => {
       const url = normalizeUrl('https://opentelemetry.io/你好');
       assert.strictEqual(url, 'https://opentelemetry.io/%E4%BD%A0%E5%A5%BD');
     });
-
-    it('should parse url with fallback', () => {
-      sinon.stub(window, 'URL').value(undefined);
-      const url = normalizeUrl('https://opentelemetry.io/你好');
-      assert.strictEqual(url, 'https://opentelemetry.io/%E4%BD%A0%E5%A5%BD');
-    });
   });
 });
-
-function getElementByXpath(path: string) {
-  return document.evaluate(
-    path,
-    document,
-    null,
-    XPathResult.FIRST_ORDERED_NODE_TYPE,
-    null
-  ).singleNodeValue;
-}
diff --git a/packages/opentelemetry-sdk-trace-web/test/window/utils.test.ts b/packages/opentelemetry-sdk-trace-web/test/window/utils.test.ts
new file mode 100644
index 0000000000..fb184c2d1b
--- /dev/null
+++ b/packages/opentelemetry-sdk-trace-web/test/window/utils.test.ts
@@ -0,0 +1,193 @@
+/*
+ * 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 * as sinon from 'sinon';
+import {
+  getElementXPath,
+  normalizeUrl,
+  parseUrl,
+  URLLike,
+} from '../../src/utils';
+
+const fixture = `
+<div>
+  <div></div>
+  <div></div>
+  <div></div>
+  <div>
+    <div></div>
+    <div>
+    </div>
+    <div id="text">lorep ipsum</div>
+    <div></div>
+    <div class="btn2">
+      foo
+      <button></button>
+      <button></button>
+      <button id="btn22"></button>
+      <button></button>
+      bar
+    </div>
+    <div>
+      aaaaaaaaa
+      <![CDATA[ /*Some code with < & and what not */ ]]>
+      <button id="btn23"></button>
+      bbb
+    </div>
+    <div></div>
+    <div id="comment"></div>
+    <div></div>
+    <div id="cdata">
+      <![CDATA[ /*Some code with < & and what not */ ]]>
+      <![CDATA[ /*Some code with < & and what not */ ]]>
+      <![CDATA[ /*Some code with < & and what not */ ]]>
+      bar
+    </div>
+    <div></div>
+  </div>
+  <div></div>
+</div>
+`;
+
+describe('utils', () => {
+  afterEach(() => {
+    sinon.restore();
+  });
+
+  describe('getElementXPath', () => {
+    let $fixture: any;
+    let child: any;
+    before(() => {
+      $fixture = $(fixture);
+      const body = document.querySelector('body');
+      if (body) {
+        body.appendChild($fixture[0]);
+        child = body.lastChild;
+      }
+    });
+    after(() => {
+      child.parentNode.removeChild(child);
+    });
+
+    it('should return correct path for element with id and optimise = true', () => {
+      const element = getElementXPath($fixture.find('#btn22')[0], true);
+      assert.strictEqual(element, '//*[@id="btn22"]');
+      assert.strictEqual(
+        $fixture.find('#btn22')[0],
+        getElementByXpath(element)
+      );
+    });
+
+    it(
+      'should return correct path for element with id and surrounded by the' +
+        ' same type',
+      () => {
+        const element = getElementXPath($fixture.find('#btn22')[0]);
+        assert.strictEqual(element, '//html/body/div/div[4]/div[5]/button[3]');
+        assert.strictEqual(
+          $fixture.find('#btn22')[0],
+          getElementByXpath(element)
+        );
+      }
+    );
+
+    it(
+      'should return correct path for element with id and and surrounded by' +
+        ' text nodes mixed with cnode',
+      () => {
+        const element = getElementXPath($fixture.find('#btn23')[0]);
+        assert.strictEqual(element, '//html/body/div/div[4]/div[6]/button');
+        assert.strictEqual(
+          $fixture.find('#btn23')[0],
+          getElementByXpath(element)
+        );
+      }
+    );
+
+    it(
+      'should return correct path for text node element surrounded by cdata' +
+        ' nodes',
+      () => {
+        const text = $fixture.find('#cdata')[0];
+        const textNode = document.createTextNode('foobar');
+        text.appendChild(textNode);
+        const element = getElementXPath(textNode);
+        assert.strictEqual(element, '//html/body/div/div[4]/div[10]/text()[5]');
+        assert.strictEqual(textNode, getElementByXpath(element));
+      }
+    );
+
+    it('should return correct path when element is text node', () => {
+      const text = $fixture.find('#text')[0];
+      const textNode = document.createTextNode('foobar');
+      text.appendChild(textNode);
+      const element = getElementXPath(textNode);
+      assert.strictEqual(element, '//html/body/div/div[4]/div[3]/text()[2]');
+      assert.strictEqual(textNode, getElementByXpath(element));
+    });
+
+    it('should return correct path when element is comment node', () => {
+      const comment = $fixture.find('#comment')[0];
+      const node = document.createComment('foobar');
+      comment.appendChild(node);
+      const element = getElementXPath(node);
+      assert.strictEqual(element, '//html/body/div/div[4]/div[8]/comment()');
+      assert.strictEqual(node, getElementByXpath(element));
+    });
+  });
+
+  describe('parseUrl', () => {
+    const urlFields: Array<keyof URLLike> = [
+      'hash',
+      'host',
+      'hostname',
+      'href',
+      'origin',
+      'password',
+      'pathname',
+      'port',
+      'protocol',
+      'search',
+      'username',
+    ];
+    it('should parse url with fallback', () => {
+      sinon.stub(globalThis, 'URL').value(undefined);
+      const url = parseUrl('https://opentelemetry.io/foo');
+      urlFields.forEach(field => {
+        assert.strictEqual(typeof url[field], 'string');
+      });
+    });
+  });
+
+  describe('normalizeUrl', () => {
+    it('should parse url with fallback', () => {
+      sinon.stub(globalThis, 'URL').value(undefined);
+      const url = normalizeUrl('https://opentelemetry.io/你好');
+      assert.strictEqual(url, 'https://opentelemetry.io/%E4%BD%A0%E5%A5%BD');
+    });
+  });
+});
+
+function getElementByXpath(path: string) {
+  return document.evaluate(
+    path,
+    document,
+    null,
+    XPathResult.FIRST_ORDERED_NODE_TYPE,
+    null
+  ).singleNodeValue;
+}