fix: Multi fill + test (#2048)

* fix: Multi fill + test

* meta: Changelog

Author: HazAT

CHANGELOG.md

@@ -2,6 +2,7 @@
 
 ## Unreleased
 
+- [browser] fix: Fixed a bug if Sentry was initialized multiple times: Fix #2043
 - [browser] ref: Mangle more stuff, reduce bundle size
 - [browser] fix: Support for ram bundle frames
 - [node] fix: Expose lastEventId method

packages/browser/test/manual/npm-build.js

@@ -59,4 +59,10 @@ function runTests() {
   const scriptEl = window.document.createElement('script');
   scriptEl.textContent = myLibrary;
   window.document.body.appendChild(scriptEl);
+
+  // Testing https://github.com/getsentry/sentry-javascript/issues/2043
+  const scriptEl2 = window.document.createElement('script');
+  scriptEl2.textContent = myLibrary;
+  window.document.body.appendChild(scriptEl2);
+  // ------------------------------------------------------------------
 }

packages/browser/test/manual/test-code.js

@@ -62,3 +62,9 @@ Sentry.withScope(scope => {
   Sentry.captureException(new TypeError('bar'));
   Sentry.captureMessage('baz');
 });
+
+var xhr = new XMLHttpRequest();
+xhr.onload = () => console.log('loaded'); // This throws error
+// xhr.addEventListener("load", () => console.log('loaded')); This does not throw error
+xhr.open('GET', 'https://httpbin.org/get');
+xhr.send();

packages/utils/src/object.ts

@@ -23,21 +23,26 @@ export function fill(source: { [key: string]: any }, name: string, replacement:
   // otherwise it'll throw "TypeError: Object.defineProperties called on non-object"
   // tslint:disable-next-line:strict-type-predicates
   if (typeof wrapped === 'function') {
-    wrapped.prototype = wrapped.prototype || {};
-    Object.defineProperties(wrapped, {
-      __sentry__: {
-        enumerable: false,
-        value: true,
-      },
-      __sentry_original__: {
-        enumerable: false,
-        value: original,
-      },
-      __sentry_wrapped__: {
-        enumerable: false,
-        value: wrapped,
-      },
-    });
+    try {
+      wrapped.prototype = wrapped.prototype || {};
+      Object.defineProperties(wrapped, {
+        __sentry__: {
+          enumerable: false,
+          value: true,
+        },
+        __sentry_original__: {
+          enumerable: false,
+          value: original,
+        },
+        __sentry_wrapped__: {
+          enumerable: false,
+          value: wrapped,
+        },
+      });
+    } catch (_Oo) {
+      // This can throw if multiple fill happens on a global object like XMLHttpRequest
+      // Fixes https://github.com/getsentry/sentry-javascript/issues/2043
+    }
   }
 
   source[name] = wrapped;

packages/utils/test/object.test.ts

@@ -33,7 +33,7 @@ describe('fill()', () => {
     expect.assertions(3);
   });
 
-  test('mulitple fills calls all functions', () => {
+  test('multiple fills calls all functions', () => {
     const source = {
       foo: (): number => 42,
     };