Update sentry config to ignore unhandled fetch exceptions

Fixes #2018

src/sidebar/util/sentry.js

@@ -51,6 +51,8 @@ export function init(config) {
   Sentry.init({
     dsn: config.dsn,
     environment: config.environment,
+    // Do not log Fetch failures to avoid inundating with unhandled fetch exceptions
+    ignoreErrors: ['Fetch operation failed'],
     release: '__VERSION__', // replaced by versionify
     whitelistUrls,
 

src/sidebar/util/test/sentry-test.js

@@ -75,6 +75,20 @@ describe('sidebar/util/sentry', () => {
       );
     });
 
+    it('configures Sentry to ignore Errors with matching the text "Fetch operation failed"', () => {
+      sentry.init({
+        dsn: 'test-dsn',
+        environment: 'dev',
+      });
+
+      assert.calledWith(
+        fakeSentry.init,
+        sinon.match({
+          ignoreErrors: ['Fetch operation failed'],
+        })
+      );
+    });
+
     it('disables the URL whitelist if `document.currentScript` is inaccessible', () => {
       fakeDocumentCurrentScript.get(() => null);