Port enabling/disabling tests

These tests doesn't actually need the complicated setup to work,
so seperated them out into a new suite. Spiritually should be the
same coverage as before, with a new test for `{ enabled: false }`.

experimental/packages/opentelemetry-instrumentation-fetch/test/fetch.msw.test.ts

@@ -0,0 +1,55 @@
+/*
+ * 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 { isWrapped } from '@opentelemetry/instrumentation';
+
+import * as assert from 'assert';
+import { FetchInstrumentation } from '../src';
+
+describe('fetch', () => {
+  describe('enabling/disabling', () => {
+    let fetchInstrumentation: FetchInstrumentation | undefined;
+
+    afterEach(() => {
+      fetchInstrumentation?.disable();
+      fetchInstrumentation = undefined;
+    });
+
+    it('should wrap global fetch when instantiated', () => {
+      assert.ok(!isWrapped(window.fetch));
+      fetchInstrumentation = new FetchInstrumentation();
+      assert.ok(isWrapped(window.fetch));
+    });
+
+    it('should not wrap global fetch when instantiated with `enabled: false`', () => {
+      assert.ok(!isWrapped(window.fetch));
+      fetchInstrumentation = new FetchInstrumentation({ enabled: false });
+      assert.ok(!isWrapped(window.fetch));
+      fetchInstrumentation.enable();
+      assert.ok(isWrapped(window.fetch));
+    });
+
+    it('should unwrap global fetch when disabled', () => {
+      fetchInstrumentation = new FetchInstrumentation();
+      assert.ok(isWrapped(window.fetch));
+      fetchInstrumentation.disable();
+      assert.ok(!isWrapped(window.fetch));
+
+      // Avoids ERROR in the logs when calling `disable()` again during cleanup
+      fetchInstrumentation = undefined;
+    });
+  });
+});

experimental/packages/opentelemetry-instrumentation-fetch/test/fetch.old.ts

@@ -368,13 +368,13 @@ describe('fetch', () => {
       clearData();
     });
 
-    it('should wrap methods', () => {
+    xit('should wrap methods', () => {
       assert.ok(isWrapped(window.fetch));
       fetchInstrumentation.enable();
       assert.ok(isWrapped(window.fetch));
     });
 
-    it('should unwrap methods', () => {
+    xit('should unwrap methods', () => {
       assert.ok(isWrapped(window.fetch));
       fetchInstrumentation.disable();
       assert.ok(!isWrapped(window.fetch));